Just something I caught... If the crank of an engine is at ten thousand RPM, the camshaft spins at half the crank speed so wouldn't the valve only be cycling at 41.5 times per second?
10000 Crank Shaft rpm Divided by 2 = (Cam Speed) That’s 5000 rpm For every rotation of the CAMSHAFT the valve’s open 1 time 5000 rpm / 60 to get revolution’s per second That is 83.333 times per second the valve opens.
@@johnniebarker9746 At one point, the older N/A Mercedes F1 engines were nudging 21k rpm! Reportedly nudging 1000hp from a 3 litre - might have been the 3.5 era - engine - all N/A!
sometimes we forget that Steve is one of the best engine builders in the country. And then he pops out a video like this one and reminds us why he is in that category.
@@joshrawlings2621you guys are delusional. Clearly you only know what you see on UA-cam. You only know of SM cause he’s on UA-cam. There are atleast 5 way better builders I can think of just off the top of my head.
@@chicago_race_engines7538 That's why I said "One of the best engine builders in the country", not "the best engine builder in the country". There's always someone better, but give him recognition for who he is. He's been at it a long long time.
As a former pro stock hemi builder I can tell you definitively why they work better boosted and not as well NA. Hemi's are capable of better airflow but for NA using high compression the chamber is a nightmare shape that burns like crap(shaped like half a grapefruit peel). Supercharged with lowered compression you can burn what you get in because the chamber is open and burns properly. High compression does not hurt a wedge nearly as bad as it does a hemi. At high compression the extra flow does not make up for the lousy chamber . To get a hemi to run at high compression you have to tighten up the chamber a LOT , that is what Ford did and also the gen 3 hemi.
This is also why the Hemi was a revelation when it was introduced in the 50s, then replaced by the B/RB wedge in stock applications in 1959. In 1952, 9:1 was “high” compression. Low compression is basically the same as a slow-burning fuel. Low compression Gen1 Hemis made more power than anything else because they had so much better flow. As fuel improved and compression came up, canted valve heads gained the advantage (first the Chrysler Poly and then the big-block Chevy and later the Lima Ford used their version of it). The true wedge (SBC, SBF, Mopar B/RB and LA/Magnum smallblock) is the simplest to mass produce and most durable mechanically because of the in-plane pushrod/rocker geometry, can have a huge quench area, but has the least flow potential. The modern Gen3 Hemi is really fascinating because of the tweaks to address all the usual Hemi low speed/street driving issues… dual plugs, ovoid-section chamber with dual quench pads. A streetable small block sized head that out of box flows as much or more than a ported BBC head.
This makes a lot of sense. Many years ago I was involved in racing an import with hemi heads. We welded the chambers and when we were finished they looked like a 351c Ford chamber. It was an N/A class and it did wonders for power.
My NA 5" bore space 650cuin ntpa Ford hemi with 83cc chamber makes 1680hp at 8900rpm on c25 and only needs 32deg timing. Maybe in the past, chamber designs weren't very good, but 99% of the trucks in the class run hemis because they simply make more horsepower.
That's why four valve engines are so good. You get the crossflow scavenging, with more valve circumference than you can get with two valves, in a shape where you can still achieve high compression.
@@stephencurry8552 You can't be serious with that statement. Did you bother looking at previous videos where Dewey is clearly banging away on the keyboard with the SolidWorks program open in plain view on the monitor? Steve may not have an engineering degree but that didn't stop him from hiring one that's been in previous videos and no, his name isn't Dewey.
Good Lord! I just caught myself answering Steve's questions and statements OUTLOUD!!! Thank You Steve. I'm a 75 year old performance addict and I'm STILL LEARNING stuff from you. I love your shop so much that I have a picture of it in my room, LOL! May God bless you and all you do for all high speed enthusiasts.
@@stevemorrisracingShame you despise NA stuff. You would build a fire Big Block dirt modified motor. A custom SMX wide bore Small block for Dirt Latemodel would not only be sweet but that’s also a massive consumer base. 950+ HP NA Carbureted motors.
@@stevemorrisracing With opposed valve location of the Hemi, the incoming intake charge helps push out the exhaust. Causes efficiency and emission issues at lower RPM, but full effort engines at high engine speeds, it's money.
People understand you make great engines. Just because Cletus got a hemi doesn’t mean your engines are any less. I’d take an SMX over that every day. Maybe one day. Keep killing it. Love your channel
Great video Steve, i’ve been an automotive mechanic for 40 years. I’ve assembled a lot of engines, but I never built an engine for horsepower until about 10 years ago no where at the level that you build engines I just have a naturally Aspirated SBC 434 making about 700 Hp And boy did I learn a lot about valvetrain really fast. I learned that shops that claim to know what they’re doing don’t , which cost me a lot of money with shotty Machine work and valve train recommendations. Guess you can say I learned the hard way. This was an excellent video describing the differences in builds for all out horsepower and then having to compromise for durability street driving and drag racing , very informative.
Keep the SBC content coming, I run one in my 61 Austin Healey and you show a lot of my ideas on it so I don't have to waste money going the wrong way ! Thanks for your time and vibes !😊❤
I saw a great video of darin morgan at BES showing a nice drawing on the path air flows from the intake to out the exhaust in a wedge head ranging from a normal non canted in line valve head like a sbc so something like DRCE 2 head where the valves are highly rotated to a full hemi where the valves are straight across from each other and how the RPM capability of the head increases the more you rotate the valves and eventually land at a hemi. Interestingly it seems wedge heads will make more low and midrange torque and hp than a hemi. I saw an interview with the guys from proline comparing the 481x to the hemi and they mentioned the 481x will tend to out 60ft the hemi. The reason ive heard that makes alot of sense is at lower rpm the hemi valve arrangement over scavenges and hurts low to mid rpm hp and torque over a wedge. That's why the hemis shine at super high rpm which is why some say that when NHRA put the 10500 rpm limit on prostock the hemis dropped away
I did watch Darin Morgan interview at Engine Performance Expo. (Super Stock Hemi Cylinder Head Porting with Darin Morgan (Expo 2024 - Episode 20) It has interesting talk about Gen2 and Gen3 Hemi heads, even its from Super Stock NA point of view. Lots of info “dos”, “don’ts”, “hows,” and “whys”.
Wonder how much street able power and torque a SMX would make NA to run in a cool street car, that’s raced about as much as you’d race your stick c7 ? aid love to put one in a truck like a 2014 -2015 extended cab f150, and just have fun…or put it in a classic car..
@@stephencurry8552 Steve did the specs first the SMX, pulling what he felt were the best aspects of Hemi and BBC engines. I believe DART (?) did the CAD/CAM coding. The CAM effort then moved to Tom Bailey’s shop and the HAAS 6 axis machine there. Steve then bought(?) the HAAS from Tom so blocks and heads are now carved out in house. Steve has an in-house CAM coder/tech
@@willecutlip That does not answer my query. There had to have been someone who actually understands metallurgy, and the actual design process who created the design. It was most obviously not steve.
Referring to Hemi vs. Wedge. I was told the reason why the Chrysler Hemi began to take over when top fuel started was simply because you could tear it down and assemble it with an air impact gun between rounds. It was just easier way back then. 😅 nowadays, your theory about the valve opening more centered in the cyl. makes the most sence. Also... yes, I would like an in-depth video about quench. I am fascinated with where Pro stock would run it and how it changes with different heat expansion of different engine materials. Ie. Aluminum rods vs. Steel. Same with blocks. I was told long ago the goal is to have the quench set up for your individual combination so the quench pads basically clean the carbon off the top of the pistons, basically just a kiss... Would enjoy hearing your story's.
@@scottconrad2719 Keeping the combustion up and in the top of the cylinder is key. I wonder about exhaust valves on hi-lift long duration camshafts all the boost going out the exhaust valves. Especially in hi- boost situations. When you think about it, it probably does loose a lot of boost on hi-lift,long duration camshafts. If the engine can't take it, it's going out the exhaust. Another point of concern is when the exhaust valve closes. It's measured in crank degrees so we need to be aware of the closings of exhaust valves because of possible valve to piston clearance issues. Evan on a R.V. camshaft, stay aware of the valve timing. I believe it is more important to keep the compression in the cylinders as well. The more squeeze,the more power we can make. That's the biggest gain we get from aftermarket camshafts. Cylinder pressure. Not compression ratio. The more compression, the more power. I said compression but I ment cylinder pressure. Just changing the camshaft is not always the best thing to do. Most performance cams just move the power to a spot that you don't want to drive at. The more aggressive the cam the higher up the RPM range the power goes. If you drive on the street, a more aggressive camshaft will probably be a dissipoi n
Love hearing all this! I am 64 years old ( Jonathan‘s dad) and learning about this is amazing. We will be at the race track this weekend!!! See you there.
Absolutely love watching thos channel I constantly learn something and thats what keeps me coming back well that and the entertainment. N while I was at World Cup I cant tell you how many people said the exact same thing about watching you and your channel and your willingness to share knowledge you don't have to let alone take the time to make a UA-cam video teaching all of us said knowledge!! Hopefully you enjoy hearing your goals of doing that are truly loved by like-minded people!!
Excellent information I like that you don't claim to know it all but are willing to take an educated guess and leave it open to other opinions and comments I think that's excellent thanks for the information and the great channel , been subscribed for a couple of months .
hi Steve, I think as you rotate the position of the valves in the cylinder head you can achieve more rpm, the big advantage of hemi i think is that the intake valve opens and uses the cylinder wall as a continuation of the seat angles and the air doesn't become turbulent when the intake valve opens, good pressure recovery. the disadvantage for N/A application is I believe in the second generation hemi, the huge combustion chamber and the dome in the piston, and the piston weight. On the other hand the huge combustion chamber is very good for forced induction to control the detonation! there are a couple videos of darin morgan who explained this very well. regards from Argentina, your channel is awesome!
Ford produced a cammer and then forgot about it cause they got banned from racing it and chev had nothing to match it.. the way forward would be OHC heads but where do we draw the line of insane horsepower.. better crankshafts , rods , pistons the list just multiplies to the point of more money wins..😂😂
I had this same thought too. It would be interesting to hear why Steve didn't go for a multi valve overhead cam cylinder head. Not so much for increasing power but improving reliability
Good ol Steve always giving his fans new content. You would think he would run out of different stuff but he mostly does not run out. I have been watching since 20 k subs and I have never looked back. Great American. Thanks Steve.
I wish this was PINNED to the top so all these bro science backyarders could hear a cylinder head design expert talk about heads and how the chamber shape and valve rotation effects everything.
I have a very very old 388 you built along time ago. Recently went to fuel tech and made 1290 wheel on a 70/30 meth/nitro blend with a gear driven procharger
I hope everyone watching this picks up on the very subtle -- but extremely important -- differences between Steve's "drag and drive" SMX engines and Promod "drag only" hemi engines. Bravo!
@@ChrisS-oo6fl As a mechanical engineer with 40 years of experience, they’re subtle 😉😊. The blocks are essentially identical (if you use Steve’s dry block) since Steve has incorporated so many Hemi features in his design. It really comes down to hemispherical head versus wedge head design and the engineering differences has been well documented since Chrysler released the hemi engine back in 1952 (see the link to the SAE technical paper). Cheers! 😁
We used to beat up on the Hemis with our 481x (SMX’s older brother) because the rules of our class didn’t allow them to take full advantage of their monster heads. We used the additional bottom end torque and made them try to run us down. Fun times! We shifted at 10500 and never hurt a bearing - EVER. definitely killed valvesprings from time to time though.
The video of Darin Morgan explaining the ford jC51 cylinder heads is amazing….. that man has forgotten more about cylinder heads than any of us could ever hope to learn…
Stupid question, as a small plane pilot, I notice that we've got 2 spark plugs per cylinder. Redundancy is nice, but its mainly for power, we check each mag/plug before each flight and when you drop a mag you have at least a 50 RPM drop. I realize they've come a long way with ignition systems, but would you also benefit from 2 plugs??? Thanks, love your channel sir 🙂
In aviation the dual plug and dual magneto setup is primarily for redundancy not power. A plane would become a very inefficient glider if only one magneto went out AND you only had one. Small aero engines are still using basically vw bug engines so very old tech but modernization is at snails pace because those old engines are proven.
I’ve always been curious if ford made a coyote that was 500+ ci, would it make more power than a hemi or a bbc? From what I understand is the 4v is superior
I think ur spot on with the valve orientation with the hemi letting more air out of the valves being in the center. Its not the volume of air but the path it takes to leave.
Steve the hemi combustion chamber is fantastic for combustion. The plug in center and cross flow works fantastic. The reason they aren’t good for na power is high compression in a hemi causes the piston to be up in the combustion chamber which messes up the flow and the combustion by jamming that dome up into the combustion. When you can use boost to make compression and run flat tops a hemi design will flat stomp. Dohc solves the rocker mess on a hemi setup but then the drive setup becomes a nightmare. Always compromises. 🤠
I agree with you as to the hemi theory. I feel as when the valves move into the center of the cylinder, the gasses can escape faster as the valve has moved away from the port in allowing a faster path to evacuate the cylinder where as in a wedge style the valve is essentially still in front of the valve port, same deal with intake
but depending on the valve angle the hemi gives up a lot of cam timing with bigger valve size due to overlap constraints. It's all trade offs. I think the wedge canted valve is actually better for a host a reasons, the valve train is more stable at high rpm as seen with prostock stuff. It's a case of, nobody's really bothered yet. I think a solid block SMX with some development would likely be competitive in top alcohol, the chamber shape on the hemi has some advantages with nitromethane that a wedge can't compete with, namely spark plug location.
@@seancollins9745 Yes forsure, I agree with you as to the cam timing 100% but I was just comparing non canted to hemi, from one extreme to another and as to why I believe the hemi is more efficient. On a wedge style I feel like the exhaust gasses get bounced back so to say instead of limited restricted flow, also believe that hemi style kind of creates a tornado effect to help completely evacuate the cylinder.
Hemi head valves are placed across the cylinder bore and inclined toward the center resulting in better airflow than a wedge design in a relatively small package. You can run bigger valves in a hemi head without issues with valve shrouding from the cylinder walls.
The hemi valves go into the center of the cylinder. The other regular heads that have big valves are shrouded on one side. Its really that simple. Air flow.
@@wingracer1614they don’t. Nhra crippled n/a hemi development early on with massive weight penalties and left the door open for wedge engines to progress…and they did. nobody has a platform to push n/a hemi development, if one existed, it would dominate.
@@wingracer1614 ehh? how are wedge better than hemispherical NA? 🤣 motorbike engines being all hemisphere headed. There is no better running NA lump than a japanese motorbike son.
@@5uprnva what do you mean nobody has pushed hemi dev? Nearly every engine in any car or motorbike here in the UK is hemispherical 😂 Wedge is an outdated concept here
We can't avoid Boyle's Law in physics. Volumetric efficiencies differ between the Hemi & Wedge head design. Simple analogy that most can wrap their melons around is you can take a gradual turn at higher speeds than you can in taking a 180° turn. Gases are on par with lightning in that they enjoy taking the path of least resistance. On another note, Dewey staring out the window yearning to chase a squirrel is always welcome. lol
most engine guys know the Hemi law, proline are the Kings of fast Hemi's Turbo, Pro charger, and NOS which ever way you want it pro line can do, they make 1000-1500hp more than the SMX when your talking over 4000hp to 5400hp is way harder to make an extra 1000hp, I like Steve but the SMX and Proline Hemi's are 2 different animals the fastest auto engines on earth is a Hemi that sits in a top fuel dragsters and funny cars, look at the street outlaw guys the fast guys use proline Hemi's Steve fixated on calling them promod their not they can come in all sorts of cars
@@Eqium pretty sure Steve stated this in the video. And what differentiates a 300k+ dollar tube chassis car from a promod? Proline engines are exactly that, promod engines!!
@@Eqium Please expand on "Hemi Law" and give a points of reference(s) that can be gleaned as there are no white papers in physics study that make mention of this 'Hemi Law' in published literature. This is the first time it's been mentioned by anyone.
@@Eqiumplease Mr LS turbo guy. Please tell us all about this Hemi Law and who discovered and wrote this law. And since you're an expert on this platform tell us all about how the engineers at Proline designed this engine.
@@EqiumSteve is referencing their use in ProMod because of fans incessantly comparing the two due to Cletus’s new engine. They see smoke where there is no fire and force Steve to respond. They have questions about the two. He’s repeatedly mentioned the other uses of a Hemi design. He’s also right, in the NA world No one runs Hemi. They just don’t. They make more power with a wedge style head. It’s not really debatable. Steve wasn’t making it about pro line. Obsessed fans are.
Phenomenal job, it is so rare to A find someone who can go through and explain all that you do,B have the knowledge to do so and willing to do so for both good and bad and C have the care and compassion to want to help teach and explain to level that most anyone that has any kind of engine knowledge that we can all not only keep up but understand and want more. As a rule most all people of your experience and or knowledge would NEVER give it the time or day nor would they ever want to give up the sacred knowledge with out wanting you to sign a non compete disclosure agreement for all the TOP SECRET INFO but in return they would want to give you an invoice at the end. Thank you so very much for what you do and if I could have my dream drive train in my dream car it would be with out any discussion or hesitation be Steve Morris powered. Thank you again.
I feel like part of the thing that makes a hemi so efficient for power is the fact that during the overlap period of the cam and just in general all of the air charge in and out of the cylinder is moving in 1 direction in a straight flow path. Where as with a wedge engine the way it comes in and out of the cylinder is 180° from eachother. So during over lap it comes in the intake makes a hard 90° toward the exhaust valve and then makes another hard 90° back out the exhaust.
Listening to Steve describe the mass inherent to the cylinder heads does point to why moving the camshafts to above the valves is the go to for F1 engines
Steve, I hereby dub thee Professor Emeritus of the Drag and Drive Horsepower. Please keep bringing these highly informative videos coming. I thought I had a fair handle on the internal combustion engine, but I always learn quite a bit from these videos. I'm the kind of guy that needs to keep learning, regardless of how old I get.
I think there are a few different reasons. As Steve mentioned, cross flow during valve overlap. The hemispherical shape of the combustion chamber with the spark plug location allows the flame front to more efficiently covert combustion energy to downward force on the piston than a wedge style head.
I agree 100% valves that opens up intake and exhaust directly in the center of the bore can make a tornado effect and intake and execute air and liquids faster. That's why they take beer and shake it in a small circle make a tornado effect it comes out comes out much faster. That's my YouTub theory 😂
Thanks Professor Steve, love the tech talk, Making sense of all the black magic, exhaust valve opens 83 per sec, so a top fuel car runs 3.70 sec on a run, the exhaust valve opens 307 times during a typical run, that is amazing.
I wonder how the hemi and the great SMX compare to a 4 valve per cylinder. Then there is a long belt or chain to deal with, so that sucks. I only dream of owning an SML or SMX. Perfect hobby Steve.
It works on motorcycles. Also can run shorter chain to a single gear on each head and have the cams gear driven. I think the 4 valve idea would make more power.
I remember watching a super slow motion video of a hemi and how the explosion would burn . The way a hemisphere engine flows makes the burn just that little more complete and can put more volume just a little more.
Thanks for all you post and educate. It’s great entertainment and educational at the same time. I hope you enjoy your little trip even though there’s quite a bit of work to do. Love the show.
Love the technical explanations The water jacketing on the SMX heads is some terrific engineering. Hemi's have great airflow and absolute crap combustion chambers. So much so, that N/A the extra airflow isn't enough to make up the difference. (that giant dome is a killer) As you have pointed out, in boosted applications, squish/quench isn't as important (and can be detrimental) while N/A it is critical. (Love to hear more about your findings here) N/A Hem'is also require a heavier piston. Of course, 4V engines have the best of both worlds- hard to package on a giant engine though. One could speculate a billet 400 inch LT based 4V V8 would be a killer drag and drive engine just because of the increased reliability. Maybe something based on the new Z06 engine
I love the details, Steve. Rod specifications, bearing journals, valve angles and sizes, rocker ratios with identical intake and exhaust rockers is genius. Wow. Best video since the piston design video you did years ago. Thank you.
No kidding. Poor Steve can’t let it go that garret bought that proline hemi. Now I get it Steve reads the comments and everyone is talking about it but don’t let it bother you man. Cleetus gave you couple hundred thousand followers overnight, just let it go
Steve I running a 9,000 RPM SBC NA and I love all this information you are giving us , been building engines for 40 years all makes and all ways learn something from your videos. What is the main difference in quench on the generation 3 hemi and the old Hemi ? Seams like quench isn't a good thing in the boosted World ?😅
I think a wedge might have better NA performance due to swirl as well. With boost you might get better mixing from the airflow and compression alone, but with the wedge you can get the swirling motion in the chamber to help mix fuel better.
Steve, everything you said about HEMI vs Wedge air flow is correct. The HEMI has a Quality and Quantity of air flow the wedge just doesn't have. This is because as you said, the Wedge valves get close to the cylinder walls. The NA HEMI would also make more power than the wedge today if the cylinder head development had not stopped for NA GEN2 (426) applications in about 1974. NHRA threw the rule book at the 426 HEMI in Prostock, the only place the NA HEMI was still run. The Prostock HEMIs had to carry an extra 600 pounds of weight when the last driver parked his car in about 1974 and said screw it!!! NA Cylinder Head development continued on the BBC because guys were still running them, to this day. GEN2 HEMI Head development did continue for blown Nitromethane heads. Billet solid heads and blocks allow those engines to make 13,000HP. PS. Your SMX heads look like they have great ports. Give us some flow numbers sometime. I know you don't care, but let us know?
Not true. The weight break system was long gone in the 80's with the 500CI rule. The last competitive CHRYSLER hemi retired in 87(Us and Roy Hill) but Glidden used a Ford hemi which had a far superior combustion chamber for a long time after that.
Steve, I agree with your explanation comparing a wedge to hemi combustion chambers. Each chamber has its advantages. I would suggest that you do some flow bench comparison tests of Hemi verses SMX. I believe there could be some gains to be had in the SMX heads. If you can rotatate the SMX chamber around a bit, you should be able to reduce the valve to cylinder wall shrouding at very high flow conditions. You could end up with the best of both worlds. The GM prostock heads flow very well, but they also have a larger intake valve than the SMX and I believe there are rotated around more than the SMX. I really enjoy watching your videos, keep up the good work.
The hemi is obviously most efficient when paired with the turbo encabulator. Chrysler invented both to work in tandem, so make sure you crank up the capacitive diractance on the pre-famulated amulite.
I always thought the advantages of a Hemi is the unshrouding (You mentioned this) and the short runner lengths with the valves sideways (90*) to a wedge, the runner can be lined up (both the intake and exhaust) to where the flow is maximized, as well as the shortest path possible through the engine. Under boost the combination of unshrouding, the inline flowpath as well as the much shorter runner length help to move everything in a more orderly fashion and much much quicker. Edit, I need to elaborate on why it's better on boost over NA, Sorry forgot that was part of the comparison. The hemi as i said has a shorter route through the CC on both Intake and exhaust But the turn in is very sharp, That will slow the charges for NA, where as boost (Blower/turbo and sometimes Nitrous) it doesn't matter as the pressure backing it compensates for lacking of easy flow (As Steve always says, "Flow doesn't matter as boost always compensates"), a wedge has a smoother albeit longer path, NA typically responds better with the smoother wedge design
If you study wet flow you will understand why the wedge is better N/A. I have spent 40 years working on wet flow thru and engine along with countless pulls on the Dyno. And what you see is the wedge will run with 8 to 10 degrees less total Ign. timing. So burn time is always faster on the wedge engine. The Hemi is better suited for slow burning fuel. I feel this is because of the lack of quench and the cross flow at overlap.
@@BlatantBurnerAccount You must understand that a 4 valve engine is no comparison to a 2 valve. I did a lot of development work on the Olds Q4 engine. Very easy to make over 2HP/ cu in. Another thing, you cannot compare small cu, in engines to large ones. It is so much easier to supply the air and camshaft needs .
@racerd9669 i know that. That wasnt the point. Size for size if you can squeeze more valve opening area in then you can shift more air/gasses. Right so big and small your 2vpc gets smoked by 4vpc in all but low down torque unless the 4vpc has valve managment. Thats just the valve arrangement nevermind the other stuff that goes with a more ideal combustion area shape.
@@BlatantBurnerAccount you seem to forget 1 thing, RPM yes that is the big advantage you have with the 4 valve engine, when you can make power at 17,000 rpm . I would hope you could power / cu. in. than any 2 valve engine.
I’d say the main benefits of the hemi head in those applications is better cylinder evacuation because during overlap the air is moving in a basically straight line where a wedge is asking the air to stop and make a u-turn on its way through. Plus the combustion chamber design makes it less prone to detonation which allow more aggressive boost and timing before you run into problems.
Top fuel guys used to say a hemi in a na configuration is good for 3 to 5 percent more hp than a wedge. And in a boosted application 10 percent more. Ive always thought that the hemi advantage was the really straight shot at the valves. And the fact when you angle the valve that much you can run a lot larger valve for the same bore size.
something interesting on the hemi topic Steve. I managed to squeeze out 50 more wheel kilowatts on my mercedes v8 just trying to copy head chamber like a hemi. Also noticed more centralised burn patterns on the pistons. This was after porting the heads and the motor has a 3.0l supercharger. Yes I guess cnc work on the chambers would be the best way, I just matched it to water volume as best I could by head. My temps even came down a bit which allowed more stability in my timing map on factory ecu.
Steve thank you for sharing your knowledge, you always remind me of my brother in law who passed away before I could learn from him. He was a huge boosted LS guy. Had his own shop, dyno, and made turbo manifolds. RIP Kyle Brown, KB Racing. Fawk Covid
Calculation of rocker frequency of actuation is correct - with the divide by two factor. However, the four stroke operation means the valve is closed for a lot of degrees of crankshaft rotation, which means the rocker is loaded much more violently than just the frequency of opening would imply.
The valves opining into the center of the cylinder on hemi are : 1) in a better location for beter evacuation/intake. 2) they are almost completely unshrouded all the way around the valve. Vs. wedge style.
I had no idea of the difference. Thanks for explaining.. But I would love to see you max out the smx. Just to see how much it could put out. Awesome videos brother keep them coming
There's a video somewhere of a shop rolling over a small engine with the head off. At a couple thousand RPM they put a BOTTLE of Coke on the piston and it didn't even foam up, It was cool to think where/ how do the valves open if the piston is really there all the time. Cool.
Steve you make perfect sense. I’m absolutely with you on the desire for low maintenance, high performance. Who wouldn’t? But there are people who wouldn’t! That’s not me 😂 I’d like to hear your quench tutorial when you find the time thank you. Enjoy your weekend and I hope you achieve all you have planned from 🇬🇧
Wow love this video! The nuts and bolts along with theory. It doesn’t get any better for a motor head. Hope to see result on this sbc build. Love how quickly u determined cam lift plus valve lift. Would have loved to see na hp for this motor before rebuild.
It’s after 3am and I’m hooked again watching another Steve video. I’m a dang electrician but these vids are so informative I get hooked. Thanks Steve, I don’t need to sleep.
I have to say I really love how you explain things so us on experience guys can really get a handle on what you're saying. I am definitely learning a lot thank you so much
I always chocked it up to the shape of the chamber. With the hemi being domed it is easy for air for flow in a less turbulent manner in and out. With a wedge the air has to hit a wall and redirect into the exhaust port. Air will flow around a sphere smoother than it will around a flat wall.
for a simple experiment, you will need a smoke machine to watch the fluid mechanics between how the air moves through a smooth radius vs a sharp corner, the same thing happens in rooms with sound traps and pressurized sound waves in the corner of a room.
@Steve. I appreciate and respect the way you break down things very logically and putting it in elementary terms with visuals and language to help us little guys understand. Thank you for all your contributions to this industry. 💯💪
Definitely want to see more cylinder head tech, especially stuff that a guy can do at home to improve stock headed motors when rebuilding for more power. Money saved is money earned
I’m definitely interested in a video about quench. I was also wondering why the hemi that Cleetus has doesn’t use captured lash caps like the SMX does.
The greater valve angle in the hemi allows a larger valve to be used (in relation to piston diameter ratio). These larger valves allow quicker cylinder filling for more high end power where that starts becoming a limitation.
As far as cylinder combustion and head design I have never seen a head design better than the Honda hurricane head design, whereas the valve trains and cams are straight up and down and the intake and exhaust flow is straight into the cylinder, one should probably take a look at the reasurch they did on the development of that particular head design because it doesn't get much better than that
Great video love hearing your explanation on the gammit of what you do ! I agree on hemis the intake valves fill better and exhaust valves exit better being the air flow central to the bore the advantage is diffenately an advantage as the the air flows more in a straight line crosses in straight path over from Intake manifold through valve into combustion chamber straight out exhaust valve straight out to exhaust manifold in a straight line. What really makes this so effective is the timing of valves taking advantage of scavenging and fill happening with overlap events, for volumetric efficiency through the exhaust and intake overlap of valves. This is where the valve geometry really shines is its volumetric efficiency gains. But that's also what boost does is increase volume of air being filled that's the reason for it being so effective together and your top fueler guys go a step further when your fuel is being dumped in marginally close to hydraulicing because the fuel also makes its own oxygen as it burns. The fuel and valve system were meant for each other in top fuel funnies and dragsters.
Hemi's are still a 4 stroke though - the air flow theory you suggest breaks down a bit as both valves are closed during the compression stroke. There would be some swirl, but not sure the valve position would help. One thing it may do is ease the flow around the valve. The wedge style valving, the gases have to do a dog leg to get around the valve head, where as with a hemi style, the gas can slip around the edges. Interesting from what you say that with N/A engines the wedge style seems better. Can't immediately think why that would change when going to boosted. Suggests that flow in and out (higher cylinder pressure) is again the important factor.
Just something I caught... If the crank of an engine is at ten thousand RPM, the camshaft spins at half the crank speed so wouldn't the valve only be cycling at 41.5 times per second?
10000 Crank Shaft rpm
Divided by 2 = (Cam Speed)
That’s 5000 rpm
For every rotation of the CAMSHAFT the valve’s open 1 time
5000 rpm / 60 to get revolution’s per second
That is 83.333 times per second the valve opens.
That is insane
@@johnniebarker9746
At one point, the older N/A Mercedes F1 engines were nudging 21k rpm! Reportedly nudging 1000hp from a 3 litre - might have been the 3.5 era - engine - all N/A!
Like you said slightly more efficient filling and exhausting let's it move more air faster
Looks like Matt and Steve had the same intention, just did the math in a different order :)
Appreciate how you don't talk down to your audience or above their heads. Terrific balance. Thanks
Thanks
sometimes we forget that Steve is one of the best engine builders in the country. And then he pops out a video like this one and reminds us why he is in that category.
Try in the World....🌎
@@joshrawlings2621you guys are delusional. Clearly you only know what you see on UA-cam. You only know of SM cause he’s on UA-cam. There are atleast 5 way better builders I can think of just off the top of my head.
@@chicago_race_engines7538 what’s the point of this comment?
@@chicago_race_engines7538
To be fair, the OP's quote was "one of the best".
Of course there's 𝘣𝘦𝘵𝘵𝘦𝘳, regardless how one defines 𝘣𝘦𝘵𝘵𝘦𝘳.
@@chicago_race_engines7538 That's why I said "One of the best engine builders in the country", not "the best engine builder in the country". There's always someone better, but give him recognition for who he is. He's been at it a long long time.
Steve, you should be able to deduct your time on this video as a charitable deduction for all the free knowledge you're bestowing on us.
As a former pro stock hemi builder I can tell you definitively why they work better boosted and not as well NA. Hemi's are capable of better airflow but for NA using high compression the chamber is a nightmare shape that burns like crap(shaped like half a grapefruit peel). Supercharged with lowered compression you can burn what you get in because the chamber is open and burns properly. High compression does not hurt a wedge nearly as bad as it does a hemi. At high compression the extra flow does not make up for the lousy chamber .
To get a hemi to run at high compression you have to tighten up the chamber a LOT , that is what Ford did and also the gen 3 hemi.
This is also why the Hemi was a revelation when it was introduced in the 50s, then replaced by the B/RB wedge in stock applications in 1959. In 1952, 9:1 was “high” compression. Low compression is basically the same as a slow-burning fuel. Low compression Gen1 Hemis made more power than anything else because they had so much better flow. As fuel improved and compression came up, canted valve heads gained the advantage (first the Chrysler Poly and then the big-block Chevy and later the Lima Ford used their version of it). The true wedge (SBC, SBF, Mopar B/RB and LA/Magnum smallblock) is the simplest to mass produce and most durable mechanically because of the in-plane pushrod/rocker geometry, can have a huge quench area, but has the least flow potential.
The modern Gen3 Hemi is really fascinating because of the tweaks to address all the usual Hemi low speed/street driving issues… dual plugs, ovoid-section chamber with dual quench pads. A streetable small block sized head that out of box flows as much or more than a ported BBC head.
This makes a lot of sense. Many years ago I was involved in racing an import with hemi heads. We welded the chambers and when we were finished they looked like a 351c Ford chamber. It was an N/A class and it did wonders for power.
My NA 5" bore space 650cuin ntpa Ford hemi with 83cc chamber makes 1680hp at 8900rpm on c25 and only needs 32deg timing. Maybe in the past, chamber designs weren't very good, but 99% of the trucks in the class run hemis because they simply make more horsepower.
That's why four valve engines are so good. You get the crossflow scavenging, with more valve circumference than you can get with two valves, in a shape where you can still achieve high compression.
@@theosmit6366 High compression isn't a problem, simply a custom piston order. My hemi is 17.1:1
When Steve Morris says something, smart people listen. Thank you for all the time you spend in your busy schedule to educate us.
He doesn't do it for free, lol. These videos make him money and increase sales which make him even more money.
james: Who is the engineer who designed the engines? Farmed out given the fact that this shop does not have an engineer(s) or CAD design office...
@@stephencurry8552
Ok, who does that computer stuff of which you mention?
@@FOH3663 Obviously American English is not your first language...
@@stephencurry8552 You can't be serious with that statement. Did you bother looking at previous videos where Dewey is clearly banging away on the keyboard with the SolidWorks program open in plain view on the monitor? Steve may not have an engineering degree but that didn't stop him from hiring one that's been in previous videos and no, his name isn't Dewey.
Good Lord! I just caught myself answering Steve's questions and statements OUTLOUD!!! Thank You Steve. I'm a 75 year old performance addict and I'm STILL LEARNING stuff from you. I love your shop so much that I have a picture of it in my room, LOL! May God bless you and all you do for all high speed enthusiasts.
I love how you have engineered durability in the SMX. You and Val are delightful, I had an awesome time in Edgewater with you guys!
Thanks!
@@stevemorrisracingShame you despise NA stuff. You would build a fire Big Block dirt modified motor. A custom SMX wide bore Small block for Dirt Latemodel would not only be sweet but that’s also a massive consumer base. 950+ HP NA Carbureted motors.
@@stevemorrisracing With opposed valve location of the Hemi, the incoming intake charge helps push out the exhaust. Causes efficiency and emission issues at lower RPM, but full effort engines at high engine speeds, it's money.
People understand you make great engines. Just because Cletus got a hemi doesn’t mean your engines are any less. I’d take an SMX over that every day. Maybe one day. Keep killing it. Love your channel
Love how Steve is always taking us to school. Good luck to you and Tom in Le Mullets.
Can't believe how awesome this is!
Great video Steve, i’ve been an automotive mechanic for 40 years. I’ve assembled a lot of engines, but I never built an engine for horsepower until about 10 years ago no where at the level that you build engines I just have a naturally Aspirated SBC 434 making about 700 Hp And boy did I learn a lot about valvetrain really fast. I learned that shops that claim to know what they’re doing don’t , which cost me a lot of money with shotty Machine work and valve train recommendations. Guess you can say I learned the hard way. This was an excellent video describing the differences in builds for all out horsepower and then having to compromise for durability street driving and drag racing , very informative.
Keep the SBC content coming, I run one in my 61 Austin Healey and you show a lot of my ideas on it so I don't have to waste money going the wrong way !
Thanks for your time and vibes !😊❤
I saw a great video of darin morgan at BES showing a nice drawing on the path air flows from the intake to out the exhaust in a wedge head ranging from a normal non canted in line valve head like a sbc so something like DRCE 2 head where the valves are highly rotated to a full hemi where the valves are straight across from each other and how the RPM capability of the head increases the more you rotate the valves and eventually land at a hemi. Interestingly it seems wedge heads will make more low and midrange torque and hp than a hemi. I saw an interview with the guys from proline comparing the 481x to the hemi and they mentioned the 481x will tend to out 60ft the hemi. The reason ive heard that makes alot of sense is at lower rpm the hemi valve arrangement over scavenges and hurts low to mid rpm hp and torque over a wedge. That's why the hemis shine at super high rpm which is why some say that when NHRA put the 10500 rpm limit on prostock the hemis dropped away
I did watch Darin Morgan interview at Engine Performance Expo. (Super Stock Hemi Cylinder Head Porting with Darin Morgan (Expo 2024 - Episode 20) It has interesting talk about Gen2 and Gen3 Hemi heads, even its from Super Stock NA point of view. Lots of info “dos”, “don’ts”, “hows,” and “whys”.
You mentioned you would discuss cylinder head quench in the video. Did I miss it? Very informative video by the way.
As always, thanks for the lesson. Such a smart, humble guy.
Wonder how much street able power and torque a SMX would make NA to run in a cool street car, that’s raced about as much as you’d race your stick c7 ? aid love to put one in a truck like a 2014 -2015 extended cab f150, and just have fun…or put it in a classic car..
@@markim5087 I’m guessing 1,200 Hp and 1,200 ft lbs of Tq on 93 octane all day long. 😎
Who is the engineer who designed the engines? Farmed out given the fact that this shop does not have an engineer(s) or CAD design office...
@@stephencurry8552 Steve did the specs first the SMX, pulling what he felt were the best aspects of Hemi and BBC engines. I believe DART (?) did the CAD/CAM coding. The CAM effort then moved to Tom Bailey’s shop and the HAAS 6 axis machine there. Steve then bought(?) the HAAS from Tom so blocks and heads are now carved out in house. Steve has an in-house CAM coder/tech
@@willecutlip That does not answer my query. There had to have been someone who actually understands metallurgy, and the actual design process who created the design. It was most obviously not steve.
I appreciate your knowledge Steve and the leg work you always do to inform us.
Referring to Hemi vs. Wedge. I was told the reason why the Chrysler Hemi began to take over when top fuel started was simply because you could tear it down and assemble it with an air impact gun between rounds. It was just easier way back then. 😅 nowadays, your theory about the valve opening more centered in the cyl. makes the most sence.
Also... yes, I would like an in-depth video about quench. I am fascinated with where Pro stock would run it and how it changes with different heat expansion of different engine materials. Ie. Aluminum rods vs. Steel. Same with blocks.
I was told long ago the goal is to have the quench set up for your individual combination so the quench pads basically clean the carbon off the top of the pistons, basically just a kiss...
Would enjoy hearing your story's.
@@scottconrad2719 Keeping the combustion up and in the top of the cylinder is key. I wonder about exhaust valves on hi-lift long duration camshafts all the boost going out the exhaust valves. Especially in hi- boost situations. When you think about it, it probably does loose a lot of boost on hi-lift,long duration camshafts. If the engine can't take it, it's going out the exhaust. Another point of concern is when the exhaust valve closes. It's measured in crank degrees so we need to be aware of the closings of exhaust valves because of possible valve to piston clearance issues. Evan on a R.V. camshaft, stay aware of the valve timing. I believe it is more important to keep the compression in the cylinders as well. The more squeeze,the more power we can make. That's the biggest gain we get from aftermarket camshafts. Cylinder pressure. Not compression ratio. The more compression, the more power. I said compression but I ment cylinder pressure. Just changing the camshaft is not always the best thing to do. Most performance cams just move the power to a spot that you don't want to drive at. The more aggressive the cam the higher up the RPM range the power goes. If you drive on the street, a more aggressive camshaft will probably be a dissipoi n
Love hearing all this!
I am 64 years old ( Jonathan‘s dad) and learning about this is amazing. We will be at the race track this weekend!!! See you there.
These kind of videos are my favorite, by a wide margin.
Absolutely love watching thos channel I constantly learn something and thats what keeps me coming back well that and the entertainment. N while I was at World Cup I cant tell you how many people said the exact same thing about watching you and your channel and your willingness to share knowledge you don't have to let alone take the time to make a UA-cam video teaching all of us said knowledge!! Hopefully you enjoy hearing your goals of doing that are truly loved by like-minded people!!
Excellent information I like that you don't claim to know it all but are willing to take an educated guess and leave it open to other opinions and comments I think that's excellent thanks for the information and the great channel , been subscribed for a couple of months .
hi Steve, I think as you rotate the position of the valves in the cylinder head you can achieve more rpm, the big advantage of hemi i think is that the intake valve opens and uses the cylinder wall as a continuation of the seat angles and the air doesn't become turbulent when the intake valve opens, good pressure recovery. the disadvantage for N/A application is I believe in the second generation hemi, the huge combustion chamber and the dome in the piston, and the piston weight. On the other hand the huge combustion chamber is very good for forced induction to control the detonation! there are a couple videos of darin morgan who explained this very well. regards from Argentina, your channel is awesome!
DOHC hemi might be interesting 🤔
It sounds like it might reduce some of the valve train issues, but it might introduce some others.
Came here to ask the same thing.
Ford produced a cammer and then forgot about it cause they got banned from racing it and chev had nothing to match it.. the way forward would be OHC heads but where do we draw the line of insane horsepower.. better crankshafts , rods , pistons the list just multiplies to the point of more money wins..😂😂
I had this same thought too. It would be interesting to hear why Steve didn't go for a multi valve overhead cam cylinder head. Not so much for increasing power but improving reliability
@@rogerbarnes9904 research and development would be a nightmare i guess.. tried n true pushrods and 2 valves doing pretty good so far at 5k HP..
It needs a k20 style head yes two more timing chains or I would like gear to gear matchup like diesels use
Good ol Steve always giving his fans new content. You would think he would run out of different stuff but he mostly does not run out. I have been watching since 20 k subs and I have never looked back. Great American. Thanks Steve.
Been following you for ages, keep it up!
Really enjoy your stuff Steve. I built engines on a much smaller engine for years. You are truly a knowledgeable builder/designer
Daron Morgan has some great videos on explaining the development of pro stock heads. Hemi, and wedge. Some great videos on Dragboss garage also.
I wish this was PINNED to the top so all these bro science backyarders could hear a cylinder head design expert talk about heads and how the chamber shape and valve rotation effects everything.
I love learning more on this high end stuff. I miss being around machine shops and all the engine building. Thx for the geeking out time.
Always super interesting and well explained!
I have a very very old 388 you built along time ago. Recently went to fuel tech and made 1290 wheel on a 70/30 meth/nitro blend with a gear driven procharger
I hope everyone watching this picks up on the very subtle -- but extremely important -- differences between Steve's "drag and drive" SMX engines and Promod "drag only" hemi engines. Bravo!
Subtle? The differences are extremely vast. He literally 30 min discussing them in great detail.
They are very different yet those that don't know still won't know and those of us that do know we already knew.
@@ChrisS-oo6fl As a mechanical engineer with 40 years of experience, they’re subtle 😉😊. The blocks are essentially identical (if you use Steve’s dry block) since Steve has incorporated so many Hemi features in his design. It really comes down to hemispherical head versus wedge head design and the engineering differences has been well documented since Chrysler released the hemi engine back in 1952 (see the link to the SAE technical paper). Cheers! 😁
@@willecutlipthr blocks arent even close😂 Hoonan and Proline hemia are nothing close to 481x like SMX is.
We used to beat up on the Hemis with our 481x (SMX’s older brother) because the rules of our class didn’t allow them to take full advantage of their monster heads. We used the additional bottom end torque and made them try to run us down. Fun times!
We shifted at 10500 and never hurt a bearing - EVER. definitely killed valvesprings from time to time though.
Darin Morgan explains the hemi vs wedge similarly.
Love the smx👍
The video of Darin Morgan explaining the ford jC51 cylinder heads is amazing….. that man has forgotten more about cylinder heads than any of us could ever hope to learn…
Stupid question, as a small plane pilot, I notice that we've got 2 spark plugs per cylinder. Redundancy is nice, but its mainly for power, we check each mag/plug before each flight and when you drop a mag you have at least a 50 RPM drop. I realize they've come a long way with ignition systems, but would you also benefit from 2 plugs??? Thanks, love your channel sir 🙂
In aviation the dual plug and dual magneto setup is primarily for redundancy not power.
A plane would become a very inefficient glider if only one magneto went out AND you only had one.
Small aero engines are still using basically vw bug engines so very old tech but modernization is at snails pace because those old engines are proven.
@@Roostfactor1that spinny thing out front is a fan to keep the pilot cool. When it turns off the pilot starts to sweat a lot. 🙃
My son said " Is there a video Steve has made that he does not pet his engine, or engine parts?" lol. I just said, that is Steve's thing.
I’ve always been curious if ford made a coyote that was 500+ ci, would it make more power than a hemi or a bbc? From what I understand is the 4v is superior
I think ur spot on with the valve orientation with the hemi letting more air out of the valves being in the center. Its not the volume of air but the path it takes to leave.
Steve the hemi combustion chamber is fantastic for combustion. The plug in center and cross flow works fantastic. The reason they aren’t good for na power is high compression in a hemi causes the piston to be up in the combustion chamber which messes up the flow and the combustion by jamming that dome up into the combustion. When you can use boost to make compression and run flat tops a hemi design will flat stomp. Dohc solves the rocker mess on a hemi setup but then the drive setup becomes a nightmare. Always compromises. 🤠
I agree with you as to the hemi theory. I feel as when the valves move into the center of the cylinder, the gasses can escape faster as the valve has moved away from the port in allowing a faster path to evacuate the cylinder where as in a wedge style the valve is essentially still in front of the valve port, same deal with intake
but depending on the valve angle the hemi gives up a lot of cam timing with bigger valve size due to overlap constraints. It's all trade offs. I think the wedge canted valve is actually better for a host a reasons, the valve train is more stable at high rpm as seen with prostock stuff. It's a case of, nobody's really bothered yet. I think a solid block SMX with some development would likely be competitive in top alcohol, the chamber shape on the hemi has some advantages with nitromethane that a wedge can't compete with, namely spark plug location.
@@seancollins9745 Yes forsure, I agree with you as to the cam timing 100% but I was just comparing non canted to hemi, from one extreme to another and as to why I believe the hemi is more efficient. On a wedge style I feel like the exhaust gasses get bounced back so to say instead of limited restricted flow, also believe that hemi style kind of creates a tornado effect to help completely evacuate the cylinder.
@@seancollins9745 smx on top fuel hahahaha you dont know what you are talking about mate.
Hemi head valves are placed across the cylinder bore and inclined toward the center resulting in better airflow than a wedge design in a relatively small package. You can run bigger valves in a hemi head without issues with valve shrouding from the cylinder walls.
The hemi valves go into the center of the cylinder. The other regular heads that have big valves are shrouded on one side. Its really that simple. Air flow.
True but that should be better for everything so why do wedge heads seem to be better NA
@@wingracer1614they don’t. Nhra crippled n/a hemi development early on with massive weight penalties and left the door open for wedge engines to progress…and they did.
nobody has a platform to push n/a hemi development, if one existed, it would dominate.
NTPA 4x4 class, 650cuin, 5" bore space, NA.
This class is dominated by hemi heads. Simply makes far more horsepower.
@@wingracer1614 ehh? how are wedge better than hemispherical NA? 🤣 motorbike engines being all hemisphere headed. There is no better running NA lump than a japanese motorbike son.
@@5uprnva what do you mean nobody has pushed hemi dev? Nearly every engine in any car or motorbike here in the UK is hemispherical 😂 Wedge is an outdated concept here
I take my hat off to you sir, nobody, but you, explain an engine in such detail the way you do,, 10/10 A+, Thank you
We can't avoid Boyle's Law in physics. Volumetric efficiencies differ between the Hemi & Wedge head design. Simple analogy that most can wrap their melons around is you can take a gradual turn at higher speeds than you can in taking a 180° turn. Gases are on par with lightning in that they enjoy taking the path of least resistance.
On another note, Dewey staring out the window yearning to chase a squirrel is always welcome. lol
most engine guys know the Hemi law, proline are the Kings of fast Hemi's Turbo, Pro charger, and NOS which ever way you want it pro line can do, they make 1000-1500hp more than the SMX when your talking over 4000hp to 5400hp is way harder to make an extra 1000hp, I like Steve but the SMX and Proline Hemi's are 2 different animals the fastest auto engines on earth is a Hemi that sits in a top fuel dragsters and funny cars, look at the street outlaw guys the fast guys use proline Hemi's Steve fixated on calling them promod their not they can come in all sorts of cars
@@Eqium pretty sure Steve stated this in the video. And what differentiates a 300k+ dollar tube chassis car from a promod? Proline engines are exactly that, promod engines!!
@@Eqium Please expand on "Hemi Law" and give a points of reference(s) that can be gleaned as there are no white papers in physics study that make mention of this 'Hemi Law' in published literature. This is the first time it's been mentioned by anyone.
@@Eqiumplease Mr LS turbo guy. Please tell us all about this Hemi Law and who discovered and wrote this law. And since you're an expert on this platform tell us all about how the engineers at Proline designed this engine.
@@EqiumSteve is referencing their use in ProMod because of fans incessantly comparing the two due to Cletus’s new engine. They see smoke where there is no fire and force Steve to respond. They have questions about the two. He’s repeatedly mentioned the other uses of a Hemi design. He’s also right, in the NA world No one runs Hemi. They just don’t. They make more power with a wedge style head. It’s not really debatable.
Steve wasn’t making it about pro line. Obsessed fans are.
Phenomenal job, it is so rare to A find someone who can go through and explain all that you do,B have the knowledge to do so and willing to do so for both good and bad and C have the care and compassion to want to help teach and explain to level that most anyone that has any kind of engine knowledge that we can all not only keep up but understand and want more. As a rule most all people of your experience and or knowledge would NEVER give it the time or day nor would they ever want to give up the sacred knowledge with out wanting you to sign a non compete disclosure agreement for all the TOP SECRET INFO but in return they would want to give you an invoice at the end. Thank you so very much for what you do and if I could have my dream drive train in my dream car it would be with out any discussion or hesitation be Steve Morris powered. Thank you again.
my guess would be the valve shrouding on a wedge heads effects on flow. and spark plug location being more centralized
I feel like part of the thing that makes a hemi so efficient for power is the fact that during the overlap period of the cam and just in general all of the air charge in and out of the cylinder is moving in 1 direction in a straight flow path. Where as with a wedge engine the way it comes in and out of the cylinder is 180° from eachother. So during over lap it comes in the intake makes a hard 90° toward the exhaust valve and then makes another hard 90° back out the exhaust.
Steve giving engine builder secrets
Listening to Steve describe the mass inherent to the cylinder heads does point to why moving the camshafts to above the valves is the go to for F1 engines
Steve, I hereby dub thee Professor Emeritus of the Drag and Drive Horsepower. Please keep bringing these highly informative videos coming. I thought I had a fair handle on the internal combustion engine, but I always learn quite a bit from these videos. I'm the kind of guy that needs to keep learning, regardless of how old I get.
Thanks for taking the time to make these videos!
Loving these tech videos, Steve you do a great job explaining where its understandable and comprehendable. Keep em coming
I think there are a few different reasons. As Steve mentioned, cross flow during valve overlap. The hemispherical shape of the combustion chamber with the spark plug location allows the flame front to more efficiently covert combustion energy to downward force on the piston than a wedge style head.
I agree 100% valves that opens up intake and exhaust directly in the center of the bore can make a tornado effect and intake and execute air and liquids faster. That's why they take beer and shake it in a small circle make a tornado effect it comes out comes out much faster. That's my YouTub theory 😂
Not quite right.. wedge heads swirl that way.. hemi flows 90 degrees to a wedge more like a rolling wave into the cylinder..
Thanks Professor Steve, love the tech talk, Making sense of all the black magic, exhaust valve opens 83 per sec, so a top fuel car runs 3.70 sec on a run, the exhaust valve opens 307 times during a typical run, that is amazing.
I wonder how the hemi and the great SMX compare to a 4 valve per cylinder. Then there is a long belt or chain to deal with, so that sucks.
I only dream of owning an SML or SMX. Perfect hobby Steve.
It works on motorcycles. Also can run shorter chain to a single gear on each head and have the cams gear driven. I think the 4 valve idea would make more power.
Billet coyote based 5.8L engines are making well over 4000hp
@@knowbull5hit590 Are they lasting?
Just unpacked my blue hoodie and I couldn't be happier. It is without any doubt the best quality hoodie ever. Cheers.
I remember watching a super slow motion video of a hemi and how the explosion would burn . The way a hemisphere engine flows makes the burn just that little more complete and can put more volume just a little more.
Thanks for all you post and educate. It’s great entertainment and educational at the same time. I hope you enjoy your little trip even though there’s quite a bit of work to do. Love the show.
Love the technical explanations
The water jacketing on the SMX heads is some terrific engineering.
Hemi's have great airflow and absolute crap combustion chambers. So much so, that N/A the extra airflow isn't enough to make up the difference. (that giant dome is a killer)
As you have pointed out, in boosted applications, squish/quench isn't as important (and can be detrimental) while N/A it is critical. (Love to hear more about your findings here)
N/A Hem'is also require a heavier piston.
Of course, 4V engines have the best of both worlds- hard to package on a giant engine though.
One could speculate a billet 400 inch LT based 4V V8 would be a killer drag and drive engine just because of the increased reliability. Maybe something based on the new Z06 engine
I love the details, Steve. Rod specifications, bearing journals, valve angles and sizes, rocker ratios with identical intake and exhaust rockers is genius. Wow. Best video since the piston design video you did years ago. Thank you.
Cleetus seems to have a lot of influence on all of your YT channels... You are great! Thank you for sharing all this insights with us. V8 Rules 🙂
No clue why I don’t get it. Bunch of goofs to me.
@@daleolson3506Vids Of Cars You Build...?
@@daleolson3506 Becareful speaking the truth, it hurts Cleety Clowns feels and they cry like woke folk who lost the election.
Could it have to do with the law of motion. The hemi has straight 😮high flow through the combustion chamber.
No kidding. Poor Steve can’t let it go that garret bought that proline hemi. Now I get it Steve reads the comments and everyone is talking about it but don’t let it bother you man. Cleetus gave you couple hundred thousand followers overnight, just let it go
Steve I running a 9,000 RPM SBC NA
and I love all this information you are giving us , been building engines for 40 years all makes and all ways learn something from your videos.
What is the main difference in quench on the generation 3 hemi and the old Hemi ? Seams like quench isn't a good thing in the boosted World ?😅
I would love to learn more about Quench, both boosted and N/A. Thanks for all the knowledge!
I think a wedge might have better NA performance due to swirl as well. With boost you might get better mixing from the airflow and compression alone, but with the wedge you can get the swirling motion in the chamber to help mix fuel better.
Steve, everything you said about HEMI vs Wedge air flow is correct. The HEMI has a Quality and Quantity of air flow the wedge just doesn't have. This is because as you said, the Wedge valves get close to the cylinder walls. The NA HEMI would also make more power than the wedge today if the cylinder head development had not stopped for NA GEN2 (426) applications in about 1974. NHRA threw the rule book at the 426 HEMI in Prostock, the only place the NA HEMI was still run. The Prostock HEMIs had to carry an extra 600 pounds of weight when the last driver parked his car in about 1974 and said screw it!!! NA Cylinder Head development continued on the BBC because guys were still running them, to this day. GEN2 HEMI Head development did continue for blown Nitromethane heads. Billet solid heads and blocks allow those engines to make 13,000HP. PS. Your SMX heads look like they have great ports. Give us some flow numbers sometime. I know you don't care, but let us know?
What you said about n/a hemi is false. (I know you think you’re right) As for the rest…thanks captain obvious for repeating him.
Not true. The weight break system was long gone in the 80's with the 500CI rule. The last competitive CHRYSLER hemi retired in 87(Us and Roy Hill) but Glidden used a Ford hemi which had a far superior combustion chamber for a long time after that.
Steve, I agree with your explanation comparing a wedge to hemi combustion chambers. Each chamber has its advantages. I would suggest that you do some flow bench comparison tests of Hemi verses SMX. I believe there could be some gains to be had in the SMX heads. If you can rotatate the SMX chamber around a bit, you should be able to reduce the valve to cylinder wall shrouding at very high flow conditions. You could end up with the best of both worlds. The GM prostock heads flow very well, but they also have a larger intake valve than the SMX and I believe there are rotated around more than the SMX. I really enjoy watching your videos, keep up the good work.
Just by design a true Hemi chamber doesnt suffer from valve shrouding like a wedge
The hemi is obviously most efficient when paired with the turbo encabulator. Chrysler invented both to work in tandem, so make sure you crank up the capacitive diractance on the pre-famulated amulite.
Idgaf about HP numbers...How durable and reliable is it? Any motor can make all the boost...but can it take it for more than single pass
I always thought the advantages of a Hemi is the unshrouding (You mentioned this) and the short runner lengths with the valves sideways (90*) to a wedge, the runner can be lined up (both the intake and exhaust) to where the flow is maximized, as well as the shortest path possible through the engine. Under boost the combination of unshrouding, the inline flowpath as well as the much shorter runner length help to move everything in a more orderly fashion and much much quicker.
Edit, I need to elaborate on why it's better on boost over NA, Sorry forgot that was part of the comparison. The hemi as i said has a shorter route through the CC on both Intake and exhaust But the turn in is very sharp, That will slow the charges for NA, where as boost (Blower/turbo and sometimes Nitrous) it doesn't matter as the pressure backing it compensates for lacking of easy flow (As Steve always says, "Flow doesn't matter as boost always compensates"), a wedge has a smoother albeit longer path, NA typically responds better with the smoother wedge design
If you study wet flow you will understand why the wedge is better N/A. I have spent 40 years working on wet flow thru and engine along with countless pulls on the Dyno. And what you see is the wedge will run with 8 to 10 degrees less total Ign. timing. So burn time is always faster on the wedge engine. The Hemi is better suited for slow burning fuel. I feel this is because of the lack of quench and the cross flow at overlap.
yeah so japanese motorbike engines must all be wrong then😂 So you know better than the guys who get 200+bhp per ltr NA for fun. Got it.
@@BlatantBurnerAccount You must understand that a 4 valve engine is no comparison to a 2 valve. I did a lot of development work on the Olds Q4 engine. Very easy to make over 2HP/ cu in. Another thing, you cannot compare small cu, in engines to large ones. It is so much easier to supply the air and camshaft needs .
@racerd9669 i know that. That wasnt the point. Size for size if you can squeeze more valve opening area in then you can shift more air/gasses. Right so big and small your 2vpc gets smoked by 4vpc in all but low down torque unless the 4vpc has valve managment. Thats just the valve arrangement nevermind the other stuff that goes with a more ideal combustion area shape.
@@BlatantBurnerAccount you seem to forget 1 thing, RPM yes that is the big advantage you have with the 4 valve engine, when you can make power at 17,000 rpm . I would hope you could power / cu. in. than any 2 valve engine.
I’d say the main benefits of the hemi head in those applications is better cylinder evacuation because during overlap the air is moving in a basically straight line where a wedge is asking the air to stop and make a u-turn on its way through. Plus the combustion chamber design makes it less prone to detonation which allow more aggressive boost and timing before you run into problems.
I vote for a new Steve Morris hemi head for a solid block. SMX call it SMXH
Yep u win the internet today I hope your having a badass weekend
Top fuel guys used to say a hemi in a na configuration is good for 3 to 5 percent more hp than a wedge. And in a boosted application 10 percent more. Ive always thought that the hemi advantage was the really straight shot at the valves. And the fact when you angle the valve that much you can run a lot larger valve for the same bore size.
you mopar guys need to stop drinking your mopar koolaid
@@superkillr ummmm what? What mention of mopar or that im somehow a mopar guy did you get from my comment?
Dewey for President.
something interesting on the hemi topic Steve. I managed to squeeze out 50 more wheel kilowatts on my mercedes v8 just trying to copy head chamber like a hemi. Also noticed more centralised burn patterns on the pistons. This was after porting the heads and the motor has a 3.0l supercharger. Yes I guess cnc work on the chambers would be the best way, I just matched it to water volume as best I could by head. My temps even came down a bit which allowed more stability in my timing map on factory ecu.
Remember steve it is always hard to explain that the sun is shining to people who keep thier heads in the sand...😊
Steve thank you for sharing your knowledge, you always remind me of my brother in law who passed away before I could learn from him. He was a huge boosted LS guy. Had his own shop, dyno, and made turbo manifolds. RIP Kyle Brown, KB Racing. Fawk Covid
NO WADER! no wader people, none
😂😂😂😂😂 this is fiiiiiine. Like a million bucks 😂😂
Need wader ,no help,no drive car and quad,now if I had a self driving quad hmm
Calculation of rocker frequency of actuation is correct - with the divide by two factor. However, the four stroke operation means the valve is closed for a lot of degrees of crankshaft rotation, which means the rocker is loaded much more violently than just the frequency of opening would imply.
It's just the way the air flows thru the motor between the 2 styles hemis flow better because of what you said with the valve opening to the center
The valves opining into the center of the cylinder on hemi are : 1) in a better location for beter evacuation/intake. 2) they are almost completely unshrouded all the way around the valve. Vs. wedge style.
I had no idea of the difference. Thanks for explaining..
But I would love to see you max out the smx. Just to see how much it could put out.
Awesome videos brother keep them coming
Gonna. Someday
There's a video somewhere of a shop rolling over a small engine with the head off. At a couple thousand RPM they put a BOTTLE of Coke on the piston and it didn't even foam up,
It was cool to think where/ how do the valves open if the piston is really there all the time. Cool.
Steve you make perfect sense.
I’m absolutely with you on the desire for low maintenance, high performance. Who wouldn’t? But there are people who wouldn’t! That’s not me 😂
I’d like to hear your quench tutorial when you find the time thank you.
Enjoy your weekend and I hope you achieve all you have planned from 🇬🇧
Wow love this video! The nuts and bolts along with theory. It doesn’t get any better for a motor head. Hope to see result on this sbc build. Love how quickly u determined cam lift plus valve lift. Would have loved to see na hp for this motor before rebuild.
It’s after 3am and I’m hooked again watching another Steve video. I’m a dang electrician but these vids are so informative I get hooked.
Thanks Steve, I don’t need to sleep.
same
I have to say I really love how you explain things so us on experience guys can really get a handle on what you're saying. I am definitely learning a lot thank you so much
I always chocked it up to the shape of the chamber. With the hemi being domed it is easy for air for flow in a less turbulent manner in and out. With a wedge the air has to hit a wall and redirect into the exhaust port. Air will flow around a sphere smoother than it will around a flat wall.
for a simple experiment, you will need a smoke machine to watch the fluid mechanics between how the air moves through a smooth radius vs a sharp corner, the same thing happens in rooms with sound traps and pressurized sound waves in the corner of a room.
@Steve. I appreciate and respect the way you break down things very logically and putting it in elementary terms with visuals and language to help us little guys understand. Thank you for all your contributions to this industry. 💯💪
Definitely want to see more cylinder head tech, especially stuff that a guy can do at home to improve stock headed motors when rebuilding for more power. Money saved is money earned
I really enjoy how you breakdown the technical explanations you give. Always cool to understand why things are done.
I’m definitely interested in a video about quench. I was also wondering why the hemi that Cleetus has doesn’t use captured lash caps like the SMX does.
The greater valve angle in the hemi allows a larger valve to be used (in relation to piston diameter ratio). These larger valves allow quicker cylinder filling for more high end power where that starts becoming a limitation.
As far as cylinder combustion and head design I have never seen a head design better than the Honda hurricane head design, whereas the valve trains and cams are straight up and down and the intake and exhaust flow is straight into the cylinder, one should probably take a look at the reasurch they did on the development of that particular head design because it doesn't get much better than that
Please tell us more about cylinder head quench. 👍
Great video love hearing your explanation on the gammit of what you do ! I agree on hemis the intake valves fill better and exhaust valves exit better being the air flow central to the bore the advantage is diffenately an advantage as the the air flows more in a straight line crosses in straight path over from Intake manifold through valve into combustion chamber straight out exhaust valve straight out to exhaust manifold in a straight line. What really makes this so effective is the timing of valves taking advantage of scavenging and fill happening with overlap events, for volumetric efficiency
through the exhaust and intake overlap of valves. This is where the valve geometry really shines is its volumetric efficiency gains. But that's also what boost does is increase volume of air being filled that's the reason for it being so effective together and your top fueler guys go a step further when your fuel is being dumped in marginally close to hydraulicing because the fuel also makes its own oxygen as it burns. The fuel and valve system were meant for each other in top fuel funnies and dragsters.
Hemi's are still a 4 stroke though - the air flow theory you suggest breaks down a bit as both valves are closed during the compression stroke. There would be some swirl, but not sure the valve position would help. One thing it may do is ease the flow around the valve. The wedge style valving, the gases have to do a dog leg to get around the valve head, where as with a hemi style, the gas can slip around the edges.
Interesting from what you say that with N/A engines the wedge style seems better. Can't immediately think why that would change when going to boosted. Suggests that flow in and out (higher cylinder pressure) is again the important factor.