I've done a lot of porting since about 1972 and agree this is oner of the best basic porting video's I've seen. There are several little things that people don't think of though. I use 6" shank burrs but cut them down to 5" or 4" which makes them easier to control when porting and is usually plenty long enough.The 'throat area' (bowl, behind valve head) is the first thing that should be done plus you need a little math to know how big it should be based on valve diameter (usually 75%~90% valve diameter) Even if your only ever doing one head, get one of David Vizard's books on porting (no affiliation, I don't get a penny recommending it) It can take a lot longer than 1~2 hrs to get a max flow high speed intake, depending on how much testing you do
I've ported the cylinder head of my fiat 115 lampredi 1.5L engine, before seeing this video. Now I watch this and seems like I did everything good, but I used a Dremel and a little conical shape stone to do all the job, LOTS of WD-40 and 40+ hours of work... I hope to win at least 5HP (the quality of the "meeteing" between the machined place for the valve seat and the port duct was very poor, with more than 6mm of lip). Have done some work on the carburetor too and made the rotating assembly loose some weight, so I would go over 100HP@5600RPM and a max of 8200RPM, good for a 1960's 1.5L engine; changing the carburation to two weber 45-45 and the engine would go over 120HP. Good content!
best video on porting by far, most of this I already know kind of from hours of reading and watching in the past years, but I'm getting ready to make my slow 350 faster and I'm just re learning and confirming stuff and learning some more. I can't believe I'm about to finish watching an hour long video on youtube, so you know it must be good.
xocohooco,hocohcpohpzjpozhopzcoxufcppxfpfxpfxpfoxffooxofxofoxfoffooxfoffoofofoxfofofoffxoxofofxfxoxfoxfoxfxofxfxfxxffoxxofxofoxfofofxoxoxofoxfofofxoffofoxofofofofofxoffxofoxfxofxoffoxofxofofofoxfoxfxofxofofofxoffoofofofofxofofxfofofoxxofoxffoofofofofofofofofofofofofofxoxofoffoofxofofofofofofofofofofofofofofofofofofofofofofofofofofofofofofoffoofofofoxfofofofofofofofofoffooffoofofofofofofofofofofofxofofxofofofofofofofxofoffofoxofofofofofxofofofofofofffxfxofoxfofoxoxggooxxofxffpoiu gfuyffff do ffchcyf by fyy by ff( ; f(iufiyfiy(
Great job on explaining even cutting those extra heads gives people an idea what it looks like with the water jackets. I usually do a light sand blasting in intake and combustion chamber just to keep the mixture but my exhaust is like a mirror... Myself I have straight and 90% angle grinder and dermal tools as well for the sanding drums and about 20 different burrs.. don't forget ear plugs.. I usually soap and water wash with small 1/2" paint brush wash them out the blow air dry.
Finally. Someone that knows what they're talking about. Velocity IS what it's all about. Air at velocity is stored energy. A CFM rating is just a number.
Not sure about that. The velocity is lost upon compression. You'll want greater volume to support a greater volume of fuel. Velocity would only affect mixing and scavenging.
MCE Performance what happens to intake port velocity when valve events are moved around? Theres more to port speed on a running engine than a pitot tube on a bench tells. Mass flow is what its all about.
@@HerrPoopschitz You are correct,a cylinder head on it's own does not make velocity,piston speed,cross section of the port,and cam events dictate velocity.
A while back I needed to get down into a header to open up a blockage, used a piece of 1/4 inch brake line about a foot long brazed a 1/4 inch rod about 1 1/5 inch back on one end and 1 1/4 inch out on the other, Epoxied a burr in the open end and went to work. Heat up the epoxy take out the burr. worked great! Good Video Thanks.
Thank you very very much for explaining terms which I have heard of, but did not really understand, raised port being a good example. the best video on this subject with good advice about not going too mad and keeping it a bit more subtle.
Correct, you shouldn't polish heads on a carbureted engin because the air and fuel is mixed in the intake manifold and can cause the fuel to bead up, but on a fuel injected engine it doesn't have that problem...
Actually they still do as the fuel and air mix in the port rather than the intake manifold and the port. You still don't want a polished surface for the same reason. Direct injection engines that don't also use port injection don't have that problem.
@@177SCmaro not really...the injectors are placed right before the valve on a PFI system (port fuel injection) so the air and fuel mix in the cylinder...there might be a very small amount of mixture in the port but not enough to cause moisture buildup...the only difference in PFI and GDI (gasoline direct injection) is that the injectors on a GDI system are placed right after the valve...the only advantage of GDI over PFI is that the fuel experiences less turbulence because the valve isn't in the way and it allows for a slightly more consistent mixture in the cylinder...
I've read good and bad comments, truth is if the Intake is a little rough, it creates turbulence. Example, stand by a creek and watch the water in the center, then the sides of the creek and watch the water churn and swirl. That's going on inside the rough cut and not mirrored porting wall hanger pretty polishing job. Now the exhaust needs as straight of a shot out of the chamber, Mirror it as high as you can, minimum cutting on the bottom, even a lip over the header bottom lip and keep reversion from trying to reenter the runner. so gas is atomized, and the exhaust is slid out faster.
Gasket matching is more hype than anything. A flow bench will show that for mild engine builds it's a waste of time. The money shot is 1 inch and less from the valves. Don't care how big your funnel is the small hole at the bottom is what's going to control the amount that's coming out! You do have it right about port velocity, it will make a well built engine scream while the over ported headed engine will be soggy until it hits the upper end. Hard running engines are well planned with combination of parts. Get one wrong and it will be $ to go slower. If you don't know what your doing, leave it alone. No porting is better than wrong porting!
I'd go so far as to say even half an inch around the valve is enough. It's certainly the best power per hour anyway. The seats too... I've seen an E7TE head flow more at .200 than it used to at .400 from bigger valves and a several (unfortunately secret) angle valve job with a good back cut and blend. That port job when it was finished (there was much more to it than that, it would have been a $2000 job if you charged it out) made I think 50hp on a mild 302 build.
The intake trick is to turn the airflow early, so it flows in an even cone around the valve. Using a junk valve drill small holes in the outer face. Tie sewing threads through the holes to observe turbulence. The exhaust responds to the same principal of turning the flow as far from the valve face as possible. Use a 70 degree, then an 80 degree valve seat stone to unshroud the bowl. Blend the guide boss, and any other sharp angles (very lightly!). If the intake ports are all slightly larger than the manifold ports forget matching. If the exhaust ports are slightly smaller than the header ports, leave it! Winning race cars have used these methods
This was an awesome presentation. The detailed info you gave was excellent until it wasn't. You tell people to go to town almost when port/gasket matching as well as bowl flowing and valve matching. You told us not to worry if we dig into the intake or valve cover bolt bosses because we can put thread sealer on our bolts. That was one of the first things I learned about porting in the mid-70s. But along with that was an admonishment to take care of the water jacket. You can't throw some thread sealer on a bolt to fix that.
Probably the best video for explaining porting. At least that I have seen. The one thing I have to disagree with is when he says liquid gas does not burn. Very poor choice of words. As a former fire fighter and medic, I can not tell you how many times I have gone to a call because people thought it was OK to throw their cigarette or a match into liquid gas. Liquid gas not only burns, but it also goes BOOM. It goes BIG BOOM. The other thing is the word is pronounced ROOF. NOT RUFF. Dogs say RUFF. Sand paper is ROUGH. The triangle shaped top of my house is a ROOF! If I told you to rhyme the word SPOOF, you would say ROOF, not RUFF! Just for future posts, the small, stream like body of water is a CREEK. It is NOT, however, a CRICK. The chunks of asphalt missing in the middle of the street leaves a POT HOLE! NOT a PAT HOLE! PAT HOLES are what you try to avoid while in prison! My mothers sister is not my ANT. Ants are little insects that run around eating crumbs. AUNTS are the women that take you for your first tattoo, buy you beer when you are too young to get it yourself. Obviously I am just making a funny and mean no disrespect. Lighten up people!
liquid gas burns of course, but when it's pooling on the sides of the port walls, it's not making its way into the combustion chamber as well to get ignited.
NO fuel that touches the cylinder wall or combustion chamber will burn. That's why larger CID combustion chambers are pollutive. It cannot burn those droplets because the surface its touching is acting as a heat sink. The fuel droplets will never reach ignition temperature. 100% guaranteed, on EVERY combustion stroke, there is unburned fuel expelled thru the exhaust. I've put hundreds of cigarettes out in gasoline and it's NEVER been enough to ignite it. The vapor is explosive when it builds in an enclosed space, such as a gas can, or the interior of your car. There is a physical boundary that allows the pressure to build inside that space, and the vapor will burn nearly instantly compared to liquid.
Best heads for porting are the 460 big block the exhaust has a peanut shaped thing in it big ass intake and really small exhaust ports and it was due to emissions take out that 1 inch bump and they flow over double on the exhaust side its crazy
If you are talking about 460 Ford I recommend DOVE-C HEADS Came on 1970 429 2bb police interceptor and they make a 460 come alive because of the small half round combustion chambers up the compression and have a better flame pattern that increases horsepower.
So what kind of upgrade should you do to the bottom. If any and or will it wear the engine faster ... you find the manifolds with ratings on them or just keep the stock one with the stock heads ? And the big manifolds are for the nice heads? And or for bigger block?
Very interresting video, thank you for sharing, I am just wandering what the valves size difference will do to the flow, or reciprocity ? It will be interrested to see a test on ported heads. I just wander if big valves are making more power particulary on the exhaust side. in another words will it also make a difference from the size between them ? 49/38 or 49/40 or 51/40 ? Great video Thanks for your time Konstantin
Wil this work for diesel engines? Also, for a diesel it’s just air. Does it make a difference if you polish the runners? Since only air is moving through the intake?
Sadly from 2030 on all combustion cars including classics will be banned from public streets in entire EU and Scandinavia :-( In Germany the Green Peoples Party gave order to shorten fuel supply from 2025 on by reducing all conventional fuel stations to only one state operated central gas station per city or county. Now they even want to slow down all the gas pumps from 20 litre per minute to 2 litre per minute...From 2027 on in the EU certain car spare parts will be banned too....as exhaust systems, turbo chargers and even some engine and gearbox oils...California and New York will do the same from 2027 on.... So no investments should be done in oil burning cars any longer....They even created a new kind of crime here, called emissions and smoke crime. "Bundesabgasbespaßungsverbot" in German....((((!
Yes and no. When the exhaust valve opens there is still residual pressure in the cylinder, around 100 psi or so, which rapidly leaves the cylinder the moment the seal is broken on the exhaust valve. This initial "blow down" is were most of the exhaust leaves the cylinder and this occurs before bottom dead center. After the piston reaches bottom whatever is left in the cylinder is forced out as the piston raises but also is being drawn out by the velocity of the exhaust as it leaves, i.e. scavenging. Near top dead center with the piston, still raising, the intake valve opens (both valves open) and the momentum and velocity of the exiting exhaust helps to draw in the air/fuel mix (again, scavenging). At some point past top dead center, as the piston is going back down, the exhaust valve closes. It's a pretty dynamic process. Remember that air and exhaust are gases so they have a certain amount of "springiness" to them as well as momentum - meaning it takes time and energy to get the gases moving and when the air "hits a wall" it "stacks up" or compresses slightly and basically rebounds, creating back and forth pressure and momentum pulses all throughout the intake and exhaust systems. We hear it as induction and exhaust noise. Well tuned intake and exhaust systems take advantage of this for more power.
I’m a sucker for punishment, landcruiser 4500 straight six yep the 24 valve monster, covig pacing myself, surprisingly I was astonished how poor the mismatch was of the intake manifold at the halfway thru chamber split flange, and the cast iron EX manifolds were about 3-4mm off-set also, at lapping stage but giving the rattle fatigue hands a rest haha, what can’t hear you, gone a bit deaf too, my dumb. What s that smoke coming out of my electric drill. Ah well , at least you confirmed I got the engineering part done good,🕺🏼
The Edelbrock heads are CNC ported to insure that all runners are the same and as large as is "practical". Most likely the only thing needed is to gasket match your Edelbrock intake manifold to the intake gasket you would buy with your Edelbrock heads. A lot of people make headers, but Edelbrock makes Headers, so I would imagine you could buy a package of heads, intake and headers and only have to work on the intake manifold to match everything up. Yes or no?
Would it help to gasket match and port the head on my 1980 Mercedes 300 Diesel. Any substantial power increase to keep pace with the traffic especially on the highway would really help.
When would you do actual porting mirror smooth? For High Flow and High Velocity do you recommend rough ports with smooth transition? Good instructions for beginners. How about undercut valves, swirl polished, SB Chevy casting numbers with a X at the end have larger intake ports to start with and a little bees wax on those fluted carbide tips keeps them sharp and doesn't have aluminum build up like ones in video, and why do exhaust ports on Chevy heads have one Port on each head in a different location? Do you recommend Port Matching Gaskets on all ports of the head? Anyway anyone that wants max performance should start with valve guides at proper angle for rocker arm alignment and valve seat height and spring boss heights equal to each other as well as valve length. Then grind or cut all ports concentric to the center of the valve guide. A flow bench is a misinterpreted correction to calibrate dis-functional imperfection of machine work and materials. Like balancing is correction for machine work and materials. Once you establish indexing all measurements the same, then you can calibrate all 16 valve spring pressures at max lift the same. In return creates more HP since seven cylinders aren't having to pull the one or two cylinders that don't have equal spring pressure or installed height. Square deck block with BHJ cam and crank centers, index throws, pistons compression heights then cc combustion chambers, otherwise you don't know what you are doing. Like most machine shops have mechanics that are trained machine operators, not machinist beware of the ones who say they do the best engine rebuild job and don't have a Rottler Boring Bar & Rottler Power hone, and a Rottler P69 Cylinderhead machine or Towbin Arp Valve Guide and Seat machine, which Sunnen Bought out Rottler took to the next level of a Quality Machinist Who knows how to locate centers (which is the shortest distance between two points) enough said ”Run what you brung" Most winners choose Dart, Brodix or other professional quality racing heads. Not a rookies pros and cons when you want what you pay for go with the quality machinist that has a winning reputation.
Alcohol requires mirror finish and so does 7000RPM. DON'T TRUST A GASKET TO INDEX YOUR HIGH DOLLAR HEADS. All heads have measurement specifications which you go by to check casting spec's before you do all that work for nothing or noting that a bumpy even finish like on a golf is good because less air is touching the port walls so the air fuel mixture can move faster. I can't watch Tom Foolery on flow bench, later.
I'm wondering if a smooth finish would be a good thing on my LPG powered engine since propane is a flammable vapor and not an atomized liquid, and thus not susceptible to the "condensation" he was referencing. I'm also wondering if it's worth the extra time and PITA to do the extra work for what amount of payoff...
Mirrors gather condensed water because they are cold(er). That's all. It has nothing to do with the shape. A *condenser* or *distillery* works on the same concept.
The way I understand it, you don't polish Port walls because you lose turbulence which is what causes the fuel to fall out of suspension, and therefore causes "puddling"
Yup. Ever use an in shower mirror that has the hot water going across the back? The lack of temperature differential eliminates the condensation. Plus any injection engine wether di or idi benifts huge from polishing and ceramic coatings. If you have iron heads and aluminum intake & carburetor then no, don’t polish the intake. Just smooth and coated with the Techline stuff. Just be aware the coatings help so much they are outlawed in most racing classes.
@@hummervs3278 Yup. A lot of people don't realize that all fuel charge that comes into contact with the cylinder walls and combustion chamber do not burn because they're transferring heat from the charge to keep it under the ignition point. That's why manufacturers are trying to reduce the surface area in the combustion chamber. It results in unburned fuel, and it can't be avoided. Larger combustion chamber surface area = more unburned fuel from heat transfer. Thermodynamics
I wonder if polishing the intake on my propane powered vehicle would have any noticeable improvement over leaving them rough since propane is a flammable vapor and not an atomized liquid? I ~do~ (rarely) have to go back to liquid gasoline as a backup fuel on the same engine, but would the trade off of having a smoother flowing LPG intake as main fuel be better than occasionally having gas "condensation" in the intake when I have to run liquid gasoline?
1. So if we gasket match, the intake runner will widen up the last inch or so til it hits the gasket, then taper back again inside the head. Shouldn't we ignore the gasket and just match the intake ports to each other? 2. I liked the flow bench test at the end, but how do you know if you lost more in velocity than gained in flow? As you said, bigger isn't nec bigger.
Someone may find it interesting that 'phase change' of water (from liquid to gas) is around x1600 expansion. Use water and you get a very good idea where gas will go but 28" water is not the same as 'vacuum cleaner motor in a superflow flow bench. Another thing to work with, it's been known since maybe 1920's (maybe even earlier?) that air doesn't like to turn more than about7 degrees so 14degree included angle inside ports is good to shoot for
I have a set of aluminum heads on a 385 ci Chevy. With 220cc intake runners, I could not find a intake gasket locally that did not cover the ports partly. I have a vicktor air gap intake. But would like to get a large port dual plane. Like dart makes. I don't want to loose the potential the heads have to make top end power. But want to see if I can gain lowend tq. Without loosing much topend power. The runners on the dual plane dart intake , seems to be kinda large, I haven't actually seen one. It's a chunk of change to buy one and not use it. That's why i haven't done anything yet! I would also like to do a bit of forced induction. I want to do a bit more street driving than i planned when the engine was built. I'd like to pick up a good bit of tq. At about 2-2.5k RPM. And up. I'd say it peaks about 4800, but starts making decent tq around 3grand. And revs to 6800. So its a mid range monkey , i wanna push the tq curve lower. And not loose much hp on top. If it peaks at 6400 is fine. Any way do you know of a good dual plane intake?
Go with 195 cc heads for more velocity, it will give you a good 30 ft lbs of torque with only robbing 2-5 cfm off the top end flow. Anyone can make horsepower by bolting on too big of parts, the trick is NOT losing TORQUE to get there. The best engine builders in the world right now get 1.47 ft. lbs of torque per cubic inch on a naturally aspirated engine. They dont compare their work to other shops by horsepower #'s, they compare their work by ft. lbs. per cubic inch of the last 10 motors they built. If you were building a screaming track only motor you could use 220 cfm on up for a 385 small block because you would have a 4000 or so stall converter with low gearing. For the street use much smaller cfm heads. Sounds crazy but it works. A tunnel ram is the middle ground of torque between a dual plenum and single plenum intake but the trick is to use vacuum secondaries on them for the street. Dual 600's will be fine, you dont need 350-400 cfm carbs.
I guess a higher lift camshaft that closes the exaust 3° before the one it has now (less valve overlap) will keep high end torque and give a little extra low end torque... that's what people here in argentina use to do with the fiat lampberdi TIPO engines.
Air isn’t vaporized water, it’s nitrogen and oxygen. Condensation is all over your walls, it’s just easier to see on a mirror. His understanding of fluid dynamics isn’t the best, but he does hit some good points. Surface roughness impacts flow and boundary layer thickness. There is a reason internal roughness is a measure of pipe quality. There is a reason that washing an airplane reduces fuel consumption. The reason people don’t polish is because it takes a lot of time and the biggest benefit is lowering the Reynolds number by removing bumps and sharp transitions. To do it right though, a smooth surface flows best. That’s physics folks.
Poor fuel atomization will result in poor combustion, so you don't want a glass finish on the intake, I've witnessed 2 stroke race engines with polished intakes burn up because the oil separated from the gas/air mixture due to lack of turbulence in the intake tract.
Race engines are also often small such as our 2L T making 680hp or 5L making about the same. In particular the 5L NA, head porting and induction design is extremely critical. It needs to make high ave hp across the rpm range. It amazes me that 57 people thumb this down. What is they disagree with given the video is factual?
If I order a set of eldelblock alum heads can I just pay eldelblock to have them done there? I can never get them to answer the phone.I have a 340 with a combo of a performer cam and intake with stock heads I need this done right!
I have a question on the comment you made about polishing and the mirror analogy at the beginning. It makes sense to me to a point, but then it occurred to me that once the engine is at operating temperature, I would think that condensation wouldn't be an issue anymore. Is this correct and if so, does it just come down to less turbulence being bad for atomization? Thanks for the great video!
This may be true for an engine that uses a carburetor and dumps imprecise amount gas down the intake. But apply a little logic here. Fuel droplets are not going condense and run down an intake port of any kind, polished or not because the heat will instantly cause the fuel to evaporate. Second and most important, there is no one size fits all method to engine tuning.
also to the point of the polished theory , the fuel should already be atomized leaving the injector, unless you have garbage injectors, or carburetors . if you want to really get technical , wouldn't it bead up when it hits the back of the valve and passes through the valve seat if that was the case?
ive been wanting to do the same with a pair of 2001-2006 2v sohc ford heads get them flowed before an after to see what i did good or bad. good luck hope can some hp
There is no such thing as a “heli-gram” Barometric pressure is measured in inches of mercury. The Romanized Greek name for mercury is hydrargyrum, which is the combined words for water and silver. So, the chemical symbol for mercury is Hg.
Having heads machined and ported . sure can-do some pocket porting, make the cash fly out your pocket fast!! But cash is power how fast do you want to go!!
Porting an iron head is like rolling a large rock up a steep hill, just buy some aftermarket heads. Your time is worth more than ported iron OEM heads.
why are you centering the gasket for port matching when you assemble the engine the gasket will fall to the lowest point unless you glue the gasket in place
Glenn Knox you do glue the gasket in place, or at least I was taught to. Originally a little contact cement carefully laid to let gasket still seal, nowadays an even spray of permatex hi tack gasket maker...
try this link ua-cam.com/channels/wtokjMoI_gz77Ti3Q7yBgg.html or this www.badasscars.com/ I am pretty sure he make these DVD's that you can purchase. He had or has a shop near Sonoma Raceway, builds a lot of engines. Bad Ass Race Engines. The town is going thru Gentrification, if you know what that is, so he is no longer out in the boonies anymore. I am pretty sure they don't want him around anymore.
Around the valve guide should it be a cone? And on a 78" 360 dodge head there is a like pocket on each bowl, should I taper off each side on the intake so as to make a wedge to not make a dead head aera?
@@Hohmies86 I have studied engine design for over 50 years. I had a SF100 in 1972 and my SF600 was serial # 11. I have done port designs for manufacturers and racing teams. But I always questioned intake port flow at different valve lifts. And what I learned is that any engine that makes outstanding TQ and HP always flows over 300cfm at .400 valve lift. And the reason for this has to do with rod to stroke ratio. The lenght of the rod to the stroke, this is what sets the demand for air as the piston goes down the bore on the intake stroke. Or where the peak flow demand will occur . And if you look at most engines you will find this point to be between 72deg to 76deg ATDC and the reason for this is that the piston has reached peak piston speed, approx. 2degs before. So this is always the point where the pressure differential has equalized and the air can no longer fall into the cylinder. Now all you have to do is measure how much valve lift your cam makes at that point. You will find that a cam with a very fast lobe will generate approx. .750 lift to make .500 lift at peak flow demand. So on a street engine with a cam of .450 lift you will find that the engine is breathing at approx. .250 valve lift. I think if you do some research on the net about peak flow demand on a 4stroke engine you will find more information. I hope this helps?
Clearest porting tutorial yet. Many thanks.
I've done a lot of porting since about 1972 and agree this is oner of the best basic porting video's I've seen. There are several little things that people don't think of though. I use 6" shank burrs but cut them down to 5" or 4" which makes them easier to control when porting and is usually plenty long enough.The 'throat area' (bowl, behind valve head) is the first thing that should be done plus you need a little math to know how big it should be based on valve diameter (usually 75%~90% valve diameter) Even if your only ever doing one head, get one of David Vizard's books on porting (no affiliation, I don't get a penny recommending it) It can take a lot longer than 1~2 hrs to get a max flow high speed intake, depending on how much testing you do
Peter Jones I literally screenshotted your comment!
I have watched many videos on porting this has been without a doubt most helpful learned me alot
This is the best tutorial I have ever seen on porting Thank you so much.
Wow! Thank you so much for your tutorial. Well explained for the person that has never done this before. All the very best to you. John.
I've ported the cylinder head of my fiat 115 lampredi 1.5L engine, before seeing this video. Now I watch this and seems like I did everything good, but I used a Dremel and a little conical shape stone to do all the job, LOTS of WD-40 and 40+ hours of work...
I hope to win at least 5HP (the quality of the "meeteing" between the machined place for the valve seat and the port duct was very poor, with more than 6mm of lip).
Have done some work on the carburetor too and made the rotating assembly loose some weight, so I would go over 100HP@5600RPM and a max of 8200RPM, good for a 1960's 1.5L engine; changing the carburation to two weber 45-45 and the engine would go over 120HP.
Good content!
best video on porting by far, most of this I already know kind of from hours of reading and watching in the past years, but I'm getting ready to make my slow 350 faster and I'm just re learning and confirming stuff and learning some more. I can't believe I'm about to finish watching an hour long video on youtube, so you know it must be good.
xocohooco,hocohcpohpzjpozhopzcoxufcppxfpfxpfxpfoxffooxofxofoxfoffooxfoffoofofoxfofofoffxoxofofxfxoxfoxfoxfxofxfxfxxffoxxofxofoxfofofxoxoxofoxfofofxoffofoxofofofofofxoffxofoxfxofxoffoxofxofofofoxfoxfxofxofofofxoffoofofofofxofofxfofofoxxofoxffoofofofofofofofofofofofofofxoxofoffoofxofofofofofofofofofofofofofofofofofofofofofofofofofofofofofofoffoofofofoxfofofofofofofofofoffooffoofofofofofofofofofofofxofofxofofofofofofofxofoffofoxofofofofofxofofofofofofffxfxofoxfofoxoxggooxxofxffpoiu gfuyffff do ffchcyf by fyy by ff( ; f(iufiyfiy(
Great job on explaining even cutting those extra heads gives people an idea what it looks like with the water jackets. I usually do a light sand blasting in intake and combustion chamber just to keep the mixture but my exhaust is like a mirror... Myself I have straight and 90% angle grinder and dermal tools as well for the sanding drums and about 20 different burrs.. don't forget ear plugs..
I usually soap and water wash with small 1/2" paint brush wash them out the blow air dry.
Best explanation I’ve seen on this topic. Great video. Keep it simple.
Finally. Someone that knows what they're talking about. Velocity IS what it's all about. Air at velocity is stored energy. A CFM rating is just a number.
Not sure about that. The velocity is lost upon compression. You'll want greater volume to support a greater volume of fuel. Velocity would only affect mixing and scavenging.
CFM is a measurement that tells you when that velocity will be achieved as per your build
MCE Performance what happens to intake port velocity when valve events are moved around? Theres more to port speed on a running engine than a pitot tube on a bench tells. Mass flow is what its all about.
@@HerrPoopschitz You are correct,a cylinder head on it's own does not make velocity,piston speed,cross section of the port,and cam events dictate velocity.
A while back I needed to get down into a header to open up a blockage, used a piece of 1/4 inch brake line about a foot long brazed a 1/4 inch rod about 1 1/5 inch back on one end and 1 1/4 inch out on the other, Epoxied a burr in the open end and went to work. Heat up the epoxy take out the burr. worked great! Good Video Thanks.
most under rated channel on youtube for this topic and topics. we need to help you grow.
I use an adjustable regulator for my air tools , when I am working around a sensitive area I back the pressure off to about 30 PSI .
Good idea
Thanks for uploading. Very well explained, i did not have to go back at all. Much appreciated and helped to understand the process clearly.
The best port video I have seen yet! Great video!!
Thank you very very much for explaining terms which I have heard of, but did not really understand, raised port being a good example. the best video on this subject with good advice about not going too mad and keeping it a bit more subtle.
Correct, you shouldn't polish heads on a carbureted engin because the air and fuel is mixed in the intake manifold and can cause the fuel to bead up, but on a fuel injected engine it doesn't have that problem...
Actually they still do as the fuel and air mix in the port rather than the intake manifold and the port. You still don't want a polished surface for the same reason. Direct injection engines that don't also use port injection don't have that problem.
@@177SCmaro not really...the injectors are placed right before the valve on a PFI system (port fuel injection) so the air and fuel mix in the cylinder...there might be a very small amount of mixture in the port but not enough to cause moisture buildup...the only difference in PFI and GDI (gasoline direct injection) is that the injectors on a GDI system are placed right after the valve...the only advantage of GDI over PFI is that the fuel experiences less turbulence because the valve isn't in the way and it allows for a slightly more consistent mixture in the cylinder...
Very informative video! Really explains how to make some power!
I thought you were grinding the valve seats until you mentioned they weren’t angle cut yet. Excellent video
looks like the 38 exhaust is even marginaly better
Very interresting test
Thank you
Great teaching technique !!! I felt like I was in autoshop class all over again!
VERY BEST VIDEO! Great for the people that build street Rods. Thanks
Excellent explanation! God bless you
Thank you very much, I've been doing these mods sense I was in eighth grade. My dad taught me. I didn't know what gains I was making.
Dang , best head porting video on youtube for sure.
I've read good and bad comments, truth is if the Intake is a little rough, it creates turbulence. Example, stand by a creek and watch the water in the center, then the sides of the creek and watch the water churn and swirl. That's going on inside the rough cut and not mirrored porting wall hanger pretty polishing job. Now the exhaust needs as straight of a shot out of the chamber, Mirror it as high as you can, minimum cutting on the bottom, even a lip over the header bottom lip and keep reversion from trying to reenter the runner. so gas is atomized, and the exhaust is slid out faster.
Wow, amazing video, thanks for making/sharing it!
Gasket matching is more hype than anything. A flow bench will show that for mild engine builds it's a waste of time. The money shot is 1 inch and less from the valves. Don't care how big your funnel is the small hole at the bottom is what's going to control the amount that's coming out! You do have it right about port velocity, it will make a well built engine scream while the over ported headed engine will be soggy until it hits the upper end. Hard running engines are well planned with combination of parts. Get one wrong and it will be $ to go slower. If you don't know what your doing, leave it alone. No porting is better than wrong porting!
I'd go so far as to say even half an inch around the valve is enough. It's certainly the best power per hour anyway.
The seats too... I've seen an E7TE head flow more at .200 than it used to at .400 from bigger valves and a several (unfortunately secret) angle valve job with a good back cut and blend. That port job when it was finished (there was much more to it than that, it would have been a $2000 job if you charged it out) made I think 50hp on a mild 302 build.
In some cases having them mismatched in an intended way on the exhaust helps make torque
Don't agree "Mr Expert".
The intake trick is to turn the airflow early, so it flows in an even cone around the valve. Using a junk valve drill small holes in the outer face. Tie sewing threads through the holes to observe turbulence. The exhaust responds to the same principal of turning the flow as far from the valve face as possible. Use a 70 degree, then an 80 degree valve seat stone to unshroud the bowl. Blend the guide boss, and any other sharp angles (very lightly!). If the intake ports are all slightly larger than the manifold ports forget matching. If the exhaust ports are slightly smaller than the header ports, leave it! Winning race cars have used these methods
Reversion on the exhaust side, aids back pressure contaminating the new intake charge
Great advice.
Yes, ridiculous to "port match" the exhaust ports to the gasket without checking the headers first.
You don't know how to do it
im giving thanks to the people that do cylinder head cut aways for educational purposes, it must be a hellacious task
This was an awesome presentation. The detailed info you gave was excellent until it wasn't.
You tell people to go to town almost when port/gasket matching as well as bowl flowing and valve matching. You told us not to worry if we dig into the intake or valve cover bolt bosses because we can put thread sealer on our bolts. That was one of the first things I learned about porting in the mid-70s. But along with that was an admonishment to take care of the water jacket. You can't throw some thread sealer on a bolt to fix that.
Thanks for the video. Porting my tine 231 3800 Series heads, need all the flow I can get cause I will be pushing it to 550 WHP.
This is pretty sweet. This stuff didn't make sense till I seen this video. Pretty sweet.
You are a great teacher thank you so much for the video this was Eazy to understand
Probably the best video for explaining porting. At least that I have seen. The one thing I have to disagree with is when he says liquid gas does not burn. Very poor choice of words. As a former fire fighter and medic, I can not tell you how many times I have gone to a call because people thought it was OK to throw their cigarette or a match into liquid gas. Liquid gas not only burns, but it also goes BOOM. It goes BIG BOOM. The other thing is the word is pronounced ROOF. NOT RUFF. Dogs say RUFF. Sand paper is ROUGH. The triangle shaped top of my house is a ROOF! If I told you to rhyme the word SPOOF, you would say ROOF, not RUFF! Just for future posts, the small, stream like body of water is a CREEK. It is NOT, however, a CRICK. The chunks of asphalt missing in the middle of the street leaves a POT HOLE! NOT a PAT HOLE! PAT HOLES are what you try to avoid while in prison! My mothers sister is not my ANT. Ants are little insects that run around eating crumbs. AUNTS are the women that take you for your first tattoo, buy you beer when you are too young to get it yourself. Obviously I am just making a funny and mean no disrespect. Lighten up people!
liquid gas burns of course, but when it's pooling on the sides of the port walls, it's not making its way into the combustion chamber as well to get ignited.
@@1flynlow Yeah I Knew what he was saying. Thanks again
@@bobbyalford2325 Of course liquid gas burns. But Vaporized gas explodes. It's the explosion that makes power inside an engine.
NO fuel that touches the cylinder wall or combustion chamber will burn. That's why larger CID combustion chambers are pollutive. It cannot burn those droplets because the surface its touching is acting as a heat sink. The fuel droplets will never reach ignition temperature. 100% guaranteed, on EVERY combustion stroke, there is unburned fuel expelled thru the exhaust.
I've put hundreds of cigarettes out in gasoline and it's NEVER been enough to ignite it.
The vapor is explosive when it builds in an enclosed space, such as a gas can, or the interior of your car. There is a physical boundary that allows the pressure to build inside that space, and the vapor will burn nearly instantly compared to liquid.
glad to see you're still around, Elvis. sure sounds like you know your gasses.
Best heads for porting are the 460 big block the exhaust has a peanut shaped thing in it big ass intake and really small exhaust ports and it was due to emissions take out that 1 inch bump and they flow over double on the exhaust side its crazy
If you are talking about 460 Ford I recommend DOVE-C HEADS Came on 1970 429 2bb police interceptor and they make a 460 come alive because of the small half round combustion chambers up the compression and have a better flame pattern that increases horsepower.
great video. Keep them coming.
So what kind of upgrade should you do to the bottom. If any and or will it wear the engine faster ... you find the manifolds with ratings on them or just keep the stock one with the stock heads ? And the big manifolds are for the nice heads? And or for bigger block?
Very interresting video, thank you for sharing, I am just wandering what the valves size difference will do to the flow, or reciprocity ? It will be interrested to see a test on ported heads.
I just wander if big valves are making more power particulary on the exhaust side. in another words will it also make a difference from the size between them ? 49/38 or 49/40 or 51/40 ?
Great video
Thanks for your time
Konstantin
I rarely watch hour long video on UA-cam but this time I did.
This is explained very well - thank you! I think I've been doing it wrong.
Amazing video thank you for sharing your knowledge !!
Excellent video. Thanks.
Wil this work for diesel engines? Also, for a diesel it’s just air. Does it make a difference if you polish the runners? Since only air is moving through the intake?
Sadly from 2030 on all combustion cars including classics will be banned from public streets in entire EU and Scandinavia :-( In Germany the Green Peoples Party gave order to shorten fuel supply from 2025 on by reducing all conventional fuel stations to only one state operated central gas station per city or county. Now they even want to slow down all the gas pumps from 20 litre per minute to 2 litre per minute...From 2027 on in the EU certain car spare parts will be banned too....as exhaust systems, turbo chargers and even some engine and gearbox oils...California and New York will do the same from 2027 on.... So no investments should be done in oil burning cars any longer....They even created a new kind of crime here, called emissions and smoke crime. "Bundesabgasbespaßungsverbot" in German....((((!
Atmospheric pressure fills the cylinder naturally, the piston forces the exhaust gasses out?
Thank you sir.
Yes and no. When the exhaust valve opens there is still residual pressure in the cylinder, around 100 psi or so, which rapidly leaves the cylinder the moment the seal is broken on the exhaust valve. This initial "blow down" is were most of the exhaust leaves the cylinder and this occurs before bottom dead center. After the piston reaches bottom whatever is left in the cylinder is forced out as the piston raises but also is being drawn out by the velocity of the exhaust as it leaves, i.e. scavenging. Near top dead center with the piston, still raising, the intake valve opens (both valves open) and the momentum and velocity of the exiting exhaust helps to draw in the air/fuel mix (again, scavenging). At some point past top dead center, as the piston is going back down, the exhaust valve closes.
It's a pretty dynamic process. Remember that air and exhaust are gases so they have a certain amount of "springiness" to them as well as momentum - meaning it takes time and energy to get the gases moving and when the air "hits a wall" it "stacks up" or compresses slightly and basically rebounds, creating back and forth pressure and momentum pulses all throughout the intake and exhaust systems. We hear it as induction and exhaust noise.
Well tuned intake and exhaust systems take advantage of this for more power.
@@177SCmaro great explanation. Intake/exhaust design is a Dark Art.
I’m a sucker for punishment, landcruiser 4500 straight six yep the 24 valve monster, covig pacing myself, surprisingly I was astonished how poor the mismatch was of the intake manifold at the halfway thru chamber split flange, and the cast iron EX manifolds were about 3-4mm off-set also, at lapping stage but giving the rattle fatigue hands a rest haha, what can’t hear you, gone a bit deaf too, my dumb. What s that smoke coming out of my electric drill. Ah well , at least you confirmed I got the engineering part done good,🕺🏼
Thanks so much. Very well done,and informative.
The Edelbrock heads are CNC ported to insure that all runners are the same and as large as is "practical". Most likely the only thing needed is to gasket match your Edelbrock intake manifold to the intake gasket you would buy with your Edelbrock heads. A lot of people make headers, but Edelbrock makes Headers, so I would imagine you could buy a package of heads, intake and headers and only have to work on the intake manifold to match everything up. Yes or no?
Ty For Sharing this Sir👍
great video! very informative. I learned a few things I didn't know
How does gas drops stick to the walls when the engine is running and 240-300 cfm is moving through the port?
Would it help to gasket match and port the head on my 1980 Mercedes 300 Diesel. Any substantial power increase to keep pace with the traffic especially on the highway would really help.
When would you do actual porting mirror smooth? For High Flow and High Velocity do you recommend rough ports with smooth transition? Good instructions for beginners. How about undercut valves, swirl polished, SB Chevy casting numbers with a X at the end have larger intake ports to start with and a little bees wax on those fluted carbide tips keeps them sharp and doesn't have aluminum build up like ones in video, and why do exhaust ports on Chevy heads have one Port on each head in a different location? Do you recommend Port Matching Gaskets on all ports of the head? Anyway anyone that wants max performance should start with valve guides at proper angle for rocker arm alignment and valve seat height and spring boss heights equal to each other as well as valve length. Then grind or cut all ports concentric to the center of the valve guide.
A flow bench is a misinterpreted correction to calibrate dis-functional imperfection of machine work and materials. Like balancing is correction for machine work and materials.
Once you establish indexing all measurements the same, then you can calibrate all 16 valve spring pressures at max lift the same. In return creates more HP since seven cylinders aren't having to pull the one or two cylinders that don't have equal spring pressure or installed height. Square deck block with BHJ cam and crank centers, index throws, pistons compression heights then cc combustion chambers, otherwise you don't know what you are doing.
Like most machine shops have mechanics that are trained machine operators, not machinist beware of the ones who say they do the best engine rebuild job and don't have a Rottler Boring Bar & Rottler Power hone, and a Rottler P69 Cylinderhead machine or Towbin Arp Valve Guide and Seat machine, which Sunnen Bought out Rottler took to the next level of a Quality Machinist Who knows how to locate centers (which is the shortest distance between two points) enough said ”Run what you brung"
Most winners choose Dart, Brodix or other professional quality racing heads. Not a rookies pros and cons when you want what you pay for go with the quality machinist that has a winning reputation.
Alcohol requires mirror finish and so does 7000RPM. DON'T TRUST A GASKET TO INDEX YOUR HIGH DOLLAR HEADS. All heads have measurement specifications which you go by to check casting spec's before you do all that work for nothing or noting that a bumpy even finish like on a golf is good because less air is touching the port walls so the air fuel mixture can move faster. I can't watch Tom Foolery on flow bench, later.
I'm wondering if a smooth finish would be a good thing on my LPG powered engine since propane is a flammable vapor and not an atomized liquid, and thus not susceptible to the "condensation" he was referencing. I'm also wondering if it's worth the extra time and PITA to do the extra work for what amount of payoff...
So do you cut the port side of the seats to eliminate sharp corner transitions?
Mirrors gather condensed water because they are cold(er). That's all. It has nothing to do with the shape. A *condenser* or *distillery* works on the same concept.
Water condenses on walls too. He just doesn't see it. And air isn't just vaporized water either.
The way I understand it, you don't polish Port walls because you lose turbulence which is what causes the fuel to fall out of suspension, and therefore causes "puddling"
Yup. Ever use an in shower mirror that has the hot water going across the back? The lack of temperature differential eliminates the condensation.
Plus any injection engine wether di or idi benifts huge from polishing and ceramic coatings.
If you have iron heads and aluminum intake & carburetor then no, don’t polish the intake. Just smooth and coated with the Techline stuff. Just be aware the coatings help so much they are outlawed in most racing classes.
@@hummervs3278 Yup. A lot of people don't realize that all fuel charge that comes into contact with the cylinder walls and combustion chamber do not burn because they're transferring heat from the charge to keep it under the ignition point. That's why manufacturers are trying to reduce the surface area in the combustion chamber. It results in unburned fuel, and it can't be avoided. Larger combustion chamber surface area = more unburned fuel from heat transfer. Thermodynamics
Undoubtedly and certainly the most educational video on UA-cam.
I ported my heads on my ls2 also did port matching. Was at 435 wheel hp after doing port work im at nearly 470 wheel hp
I wonder if polishing the intake on my propane powered vehicle would have any noticeable improvement over leaving them rough since propane is a flammable vapor and not an atomized liquid? I ~do~ (rarely) have to go back to liquid gasoline as a backup fuel on the same engine, but would the trade off of having a smoother flowing LPG intake as main fuel be better than occasionally having gas "condensation" in the intake when I have to run liquid gasoline?
And when I say "polishing the intake" I mean all of the associated intake parts, including the ports in the heads, etc....
M Demers i
1. So if we gasket match, the intake runner will widen up the last inch or so til it hits the gasket, then taper back again inside the head. Shouldn't we ignore the gasket and just match the intake ports to each other?
2. I liked the flow bench test at the end, but how do you know if you lost more in velocity than gained in flow? As you said, bigger isn't nec bigger.
Someone may find it interesting that 'phase change' of water (from liquid to gas) is around x1600 expansion. Use water and you get a very good idea where gas will go but 28" water is not the same as 'vacuum cleaner motor in a superflow flow bench. Another thing to work with, it's been known since maybe 1920's (maybe even earlier?) that air doesn't like to turn more than about7 degrees so 14degree included angle inside ports is good to shoot for
pressure temperature movement of the valve
So cut the heads in half to make it easier to port?
I have a set of aluminum heads on a 385 ci Chevy. With 220cc intake runners, I could not find a intake gasket locally that did not cover the ports partly. I have a vicktor air gap intake. But would like to get a large port dual plane. Like dart makes. I don't want to loose the potential the heads have to make top end power. But want to see if I can gain lowend tq. Without loosing much topend power. The runners on the dual plane dart intake , seems to be kinda large, I haven't actually seen one. It's a chunk of change to buy one and not use it. That's why i haven't done anything yet! I would also like to do a bit of forced induction. I want to do a bit more street driving than i planned when the engine was built. I'd like to pick up a good bit of tq. At about 2-2.5k RPM. And up. I'd say it peaks about 4800, but starts making decent tq around 3grand. And revs to 6800. So its a mid range monkey , i wanna push the tq curve lower. And not loose much hp on top. If it peaks at 6400 is fine. Any way do you know of a good dual plane intake?
Go with 195 cc heads for more velocity, it will give you a good 30 ft lbs of torque with only robbing 2-5 cfm off the top end flow. Anyone can make horsepower by bolting on too big of parts, the trick is NOT losing TORQUE to get there. The best engine builders in the world right now get 1.47 ft. lbs of torque per cubic inch on a naturally aspirated engine. They dont compare their work to other shops by horsepower #'s, they compare their work by ft. lbs. per cubic inch of the last 10 motors they built. If you were building a screaming track only motor you could use 220 cfm on up for a 385 small block because you would have a 4000 or so stall converter with low gearing. For the street use much smaller cfm heads. Sounds crazy but it works. A tunnel ram is the middle ground of torque between a dual plenum and single plenum intake but the trick is to use vacuum secondaries on them for the street. Dual 600's will be fine, you dont need 350-400 cfm carbs.
I guess a higher lift camshaft that closes the exaust 3° before the one it has now (less valve overlap) will keep high end torque and give a little extra low end torque... that's what people here in argentina use to do with the fiat lampberdi TIPO engines.
Air isn’t vaporized water, it’s nitrogen and oxygen. Condensation is all over your walls, it’s just easier to see on a mirror. His understanding of fluid dynamics isn’t the best, but he does hit some good points. Surface roughness impacts flow and boundary layer thickness. There is a reason internal roughness is a measure of pipe quality. There is a reason that washing an airplane reduces fuel consumption. The reason people don’t polish is because it takes a lot of time and the biggest benefit is lowering the Reynolds number by removing bumps and sharp transitions. To do it right though, a smooth surface flows best. That’s physics folks.
Poor fuel atomization will result in poor combustion, so you don't want a glass
finish on the intake, I've witnessed 2 stroke race engines with polished intakes
burn up because the oil separated from the gas/air mixture due to lack of
turbulence in the intake tract.
Race engines are also often small such as our 2L T making 680hp or 5L making about the same. In particular the 5L NA, head porting and induction design is extremely critical. It needs to make high ave hp across the rpm range.
It amazes me that 57 people thumb this down. What is they disagree with given the video is factual?
so basically if you turbo a car like im gonna do to my v6 ecotec. i should port my heads then?
If I order a set of eldelblock alum heads can I just pay eldelblock to have them done there? I can never get them to answer the phone.I have a 340 with a combo of a performer cam and intake with stock heads I need this done right!
how would it lose flow going to a higher lift? What about that valve being pushed down farther hurts flow?
Very well explained. NICE.
Awesome video best I've seen so far
Hi...AMAZING, educational video! What is the name of your machine shop and where, thanks from Houston, TX
Ha ha the Jedi head master , That boys and girls is what we call an “expert “
Great job, very practical
Some really good info here, well made vid, good explanations, subscribed.
One question,would I have to change the existing valves if I ported out the heads
No. Provided you don't really hog out the ports, you can safely use factory valves and valve sizes.
I have a question on the comment you made about polishing and the mirror analogy at the beginning. It makes sense to me to a point, but then it occurred to me that once the engine is at operating temperature, I would think that condensation wouldn't be an issue anymore. Is this correct and if so, does it just come down to less turbulence being bad for atomization? Thanks for the great video!
Can u just port ur stock heads and intake
This may be true for an engine that uses a carburetor and dumps imprecise amount gas down the intake. But apply a little logic here. Fuel droplets are not going condense and run down an intake port of any kind, polished or not because the heat will instantly cause the fuel to evaporate. Second and most important, there is no one size fits all method to engine tuning.
hot fuel cold air cold walls good injectors high pressure
also to the point of the polished theory , the fuel should already be atomized leaving the injector, unless you have garbage injectors, or carburetors . if you want to really get technical , wouldn't it bead up when it hits the back of the valve and passes through the valve seat if that was the case?
which ones are good m8
I ported the heads on my 52 flathead and now she's cranking out 97hp at the crank
Great video, I have a set of junk heads I'm going to port for fun.
ive been wanting to do the same with a pair of 2001-2006 2v sohc ford heads get them flowed before an after to see what i did good or bad. good luck hope can some hp
nice video. Thank you.
WD40 on your carbide cutters works wonders, cuts faster and resists loading up the cutter. You can use candle wax as well, you’re welcome.
Helo grams of water??? He makes some good points and obviously has spent time in grade but saying stuff like "helo grams of water" kills credibility.
Donald Shidal maybe its not him lacking knowledge
@@johnsonbobo2376 lol, you got that right.
There is no such thing as a “heli-gram” Barometric pressure is measured in inches of mercury. The Romanized Greek name for mercury is hydrargyrum, which is the combined words for water and silver. So, the chemical symbol for mercury is Hg.
Having heads machined and ported . sure can-do some pocket porting, make the cash fly out your pocket fast!! But cash is power how fast do you want to go!!
This is a Copyrighted Video from Aaron Johnson/ Bad Ass Racing Engines.
Porting an iron head is like rolling a large rock up a steep hill, just buy some aftermarket heads. Your time is worth more than ported iron OEM heads.
I was hoping he would cover valve shrouding.
awesome
Thank you sir !
Awesome video
Gonna bacics some ports in my oven!!!!
excellent video!!!
why are you centering the gasket for port matching when you assemble the engine the gasket will fall to the lowest point unless you glue the gasket in place
Glenn Knox you do glue the gasket in place, or at least I was taught to. Originally a little contact cement carefully laid to let gasket still seal, nowadays an even spray of permatex hi tack gasket maker...
Does anyone have any idea as to what series this is from? Name of show or his name?
try this link
ua-cam.com/channels/wtokjMoI_gz77Ti3Q7yBgg.html
or this
www.badasscars.com/
I am pretty sure he make these DVD's that you can purchase. He had or has a shop near Sonoma Raceway, builds a lot of engines. Bad Ass Race Engines. The town is going thru Gentrification, if you know what that is, so he is no longer out in the boonies anymore. I am pretty sure they don't want him around anymore.
Between old production heads, Chevy obviously flows better.
Dykem blue or spray paint works wonders for scribing you port openings…you’re welcome.
Around the valve guide should it be a cone? And on a 78" 360 dodge head there is a like pocket on each bowl, should I taper off each side on the intake so as to make a wedge to not make a dead head aera?
Thanks big-dawg! I learned so much! 🤟🏿👌🏿💯
You would need a cam of .700 lift to get the engine to breath at .500 lift
Racer D how do I learn how you know that..... serious question!
@@Hohmies86 I have studied engine design for over 50 years. I had a SF100 in 1972 and my SF600 was serial # 11. I have done port designs for manufacturers and racing teams. But I always questioned intake port flow at different valve lifts. And what I learned is that any engine that makes outstanding TQ and HP always flows over 300cfm at .400 valve lift. And the reason for this has to do with rod to stroke ratio. The lenght of the rod to the stroke, this is what sets the demand for air as the piston goes down the bore on the intake stroke. Or where the peak flow demand will occur . And if you look at most engines you will find this point to be between 72deg to 76deg ATDC and the reason for this is that the piston has reached peak piston speed, approx. 2degs before. So this is always the point where the pressure differential has equalized and the air can no longer fall into the cylinder. Now all you have to do is measure how much valve lift your cam makes at that point. You will find that a cam with a very fast lobe will generate approx. .750 lift to make .500 lift at peak flow demand. So on a street engine with a cam of .450 lift you will find that the engine is breathing at approx. .250 valve lift.
I think if you do some research on the net about peak flow demand on a 4stroke engine you will find more information. I hope this helps?