It's not just the peak HP and peak torque that matters, it's area under the curve. And, as Darin Morgan says, port velocity makes engines accelerate vehicles.
I've used the AFR 265's and Brodix Race Rite 270's on 496's and they were absolute monsters. One was a '70 Nova with a 2.73 gear and the other a 68 Chevelle SS with 3.73's. The 2.73's were fine. That big motor didn't care what gears the car had. The 3.73's were just ridiculous. No traction in any gear.
I'm still impressed with the performance of the peanut ports. I remember when Chevy came out with the SS454 pick up truck back in 1990. Everyone said it was totally lacking in performance all due to the peanut port heads. Guys were doing top end swaps and were getting good performance from them but of course that also included a new cam. After watching Richard dyno test peanut ports several times the only conclusion is that they are really decent heads. I have been a long time Pontiac guy and I can tell you that stock high performance D-port Pontiac heads will not make 512 on a 455. 450 is about all you will ever see and that's with a single plane intake and really big cam. And these are heads us Pontiac guys always considered pretty good.
I am always interested in BBC heads. Like you said, we were all "conditioned" to believe that rec ports are the way to go for performance. I ran the stock ovals for years. Then I finally got to buy some closed chamber rec ports and intake from a '68 427. I am not sure I am much better off, at least on a street car. On my next engine I think I will go oval port.
I bought a '70 Corvette back in the mid '90's. It had a '70 LS6 in it that was totally stock. It ran great but I sold the top end off the engine and built a set of 049 oval ports using John Lingenfelter's advice from the pages of Hot Rod magazine. My quarter mile times went from 12.90's to 12.30's and the car was more docile during street driving. The short block, including the cam was unchanged. Performer RPM intake instead of the stock GM, but the same 850 Holley double pumper that was on the LS6 and the same factory Big Block Corvette iron exhaust manifolds. Oddly enough my trap speeds were similar, 114 with the oval ports and 112 with the rec ports. I guess the bigger ports were coming on strong on the big end.
I think it would be really interesting to test factory Chevy rectangle port vs. factory Chevy oval port heads on the same engine back to back. You could find some late 1960's closed chamber oval port heads and test them on your L78 396 and LS6 454 engines using a vintage Edelbrock C-396 oval port dual plane high rise intake. Another interesting test IMO, would be to test your L78 engine stock with headers and then blueprint and modify it to the 1967 NHRA rule book for "stock" class racing and dyno. Then modify for "super stock" class racing and dyno.
The 265 AFR's are benefiting from the higher intake velocity that you get from a smaller port area. That's why peanut port heads hold their own up to about 5000 rpm. Keeping intake velocity up makes power and torque. The Speedmasters aren't bad heads. Their ports just have too much area for this test. Air entering the head slows down. I'd love to see a Speedmaster 270 aluminum oval port head hit the market. Lots of guys would run them on the street if for no other reason than to take some weight of the front end. Great test!
It looks like the springs were giving up around 5500 on the procomp heads? Power goes flat and then dives… if you did a little porting cleanup on the procomp would that do much or maybe they already did that from the factory?
It has to do with VELOCITY. The bigger port is too big, which SLOWS THE VELOCITY, this is not good for power. Port design also has a significant impact on flow, especially with the big block Chevy, which is affected much more than most engines by this.
Here are some data points from 1967-1968 NHRA drag times for rectangle port 396/375hp cars in A/S, SS/C and SS/D classes versus oval port 396/325hp cars in SS/E and SS/EA classes: From 1967 races: 1967 SS396/375 Camaro, Bill Thomas, NHRA SS/C, 4sp, 3,508 lbs: 11.85 @ 119.86 mph 1966 SS396/375 Chevelle, Wally Booth/Dick Arons, SS/D, 4sp: 11.80 @ 119.36 mph 1967 SS396/375 Camaro, Bill Jenkins, SS/C, 4sp: 11.51 @ 115.97 (not full pass) 1967 SS396/325 Camaro, Dick Arons, SS/EA, TH400, 3,217 lbs: 11.63 @ 118 mph 1966 SS396/375 Chevelle, Mike Hoover, A/S, 4sp: 12.01 @ 117.18 mph From 1968 races: 1968 SS396/375 Camaro, Kelly Chadwick, SS/C, 4sp: 11.30@124 mph 1968 SS396/325 Camaro, Jim Baker/Bill Thomas, SS/EA, TH400, 3,308 lbs: 11.67 @ 120.95 mph 1968 SS396/375 Nova, Ed Hedrick/Jenkins, SS/D, 4sp: 11.30 @ 123.38 mph 1967 SS396/375 Camaro, Bill Jenkins, SS/C, 4sp: 11.18 @ 124.48 (also ran 11.05, Jenkins claimed 540hp on dyno) 1968 SS396/325 Camaro, Christie Fisher, SS/E, 4sp, 3,250 lbs: 11.55 @ 121 mph 1968 SS396/375 Camaro, Dale Armstrong/Dana, SS/C, 4sp., L89 alum. head, 3,162 lbs: 10.61 @ 128 mph For NHRA SS class, cars could use any stock appearing single 4 bbl intake and any flat tappet cam, but must use stock carb so SS/E and SS/EA 325hp cars ran with stock Quadrajet. Also, in 1968, NHRA factored iron head L78 396 at 425hp and factored aluminum headed L78/L89 at 435 hp. Per NHRA, shipping weight for L78 car was 3,235 lbs and shipping weight for L78/L89 was 3,162 lbs for SS/C class. Dale Armstrong's Dana '68 L78/L89 Camaro was basically a 396 cid L88 since it ran L88 heads, L88 intake with gutted plenum and 2nd design L88 cam.
Long ago I had a 461 bbc with closed chamber oval port heads. Was ~ 12:1 compression and a street car that made 512 hp. Got tired of mixing expensive race fuel with pump gas. Switched to open chamber 990 square ports and a different intake, and lowered the compression to ~ 10.5:1. Then on pump gas it made 573 hp, a 61 hp gain. Oval wasn’t the best in my situation when using factory cast iron heads. The car picked up considerable et as well.
My old cast iron 702 heads are working really good for me. Closed chamber oval ports with bigger valves and mild porting on the SSR and chamber walls plunge cut to unshroud the intake valves. With 9.5:1 CR and a small Clay Smith HR 221/235 @0.050” o.577” lift and a 3310 VS Holley. When the back barrels open it blows the tires off. These hemis, camaras and mustangs gonna learn not to mess with the patina ‘72 C10 in SW Houston....😂😂😂
The ProComp/Speedmaster heads aren't mostly bad. If you're good at porting and cleaning up the intake port they're worth the money to buy them bare, second hand for $300-400 a set. Everything else about the heads in a built config is garbage. Springs, seals, valves, all garbage. The biggest issue is the crap porting and the massive valve seat overhang. Flow numbers aren't everything, how clean they flow is just as important. If you are good with a grinder you can get in there and clean most/all of that up. Just have to be real careful when cleaning up the valve seat overhang/lip to not get in to the sealing surface. Friend and I did a similar test between Speedmaster's and TrickFlow heads on a SBM 318. After cleaning up the Speedmaster's and building them with good parts they were only 9 HP under the TrickFlow's with very similar torque and power curves.
Great test, I always enjoy a test showing that bigger is not necessarily better. I don't know how often resale comes into play for most hot rod folk with their car / engine parts but the AFRs come out ahead here too for me and likely most.
Is all about flow. CC size of the chambers isn’t as important as the flow. It’s still important, just not as important as manufacturers want you to believe. Why a 950cfm carb? That’s way more than that build will utilize.
Not all of us have big budgets for cylinder heads. On Summit you can get bare "as cast"heads, it would be interestibg to see a build of those to get them running well. Id imagjne they would need to be completely gone through but maybe save a few bucks in the long run
That was a great test! Who is not going to pick a bigger port for less money right? Unless it’s a budget breaker I would spend the money on the AFRs. Fifty hp is just too much to leave on the table and I think you get better quality overall and probably better reliability as well. I have seen this on other parts as well. For example has anybody ever seen a test where a Performer RPM intake does not make more power than seemingly identical knock offs?
I didn’t hear you mention chamber/compression ratio differences. The factory heads vary all over, and you did flash the 112 cc up for the AFRs. The CR can move the meat of the torque curve up or down quite a bit. Those AFR ovals seem to work really well. Thanks, Richard!
With the engines I run, this is easy, we tend to go with CFM at various lifts to tell what we should run rather than port volume. I like to chase torque rather than HP, because most of my engines live under 6000rpm, so port velocity is far more important to me than port volume or cross section. With Pontiac engines and only having one Chy-na budget head available, we usually port all of them anyway. Who does the porting makes a difference. A friend of mine has an engine of the same CI and compression, but he is making less power because of the port work, and supposedly his heads flow more. However what mine flow at .550 lift his flow at .700. So many interesting parameters and effects of the various engine designs, they're more than just air pumps, though you can expect certain things that are similar across all of them. The difference is where they make their power and what the ultimate limits are. Thats why I like to see what the other engines do, what the torque curves look like, and what effects changes have. I really like the grunt engines though, even if they are harder to get to hook up.
agreed--focus on what a head flows at full valve lift, and you are aiming for the shortest duration of time the entire valve is in motion. Focus on lower valve lift flow, and you gain when the valve races to full lift and then gain when its closing. Most "dyno queens" don't get this, they just want to brag about a big number (though it's too bad Speedmaster didn't create smaller ports with thick walls to let the buyer port to their needs). Also, port flow rating can change depending on how small a bore the head sits on due to cylinder wall shrouding--the average rat needs that .060" overbore. and then there's combustion design--you cram a bunch of air in but the fuel droplets separate and you get a lousy burn. were i building a "cheap" motorhome powerplant, i'd go with the Speedmaster setup over cast iron and enjoy the potential detonation cushion. But BDFC of the smaller ports might factor in.
@@albertgaspar627 I have a 1971 Travco RV I have been thinking about swapping an engine into. It has a good running but anemic 413 Chrysler in it right now. man does that thing drink the gas. I have several 6.0 LS engines from rusted out trucks, and some 4L80 transmissions, so it stands to reason that a Truck Norris cam with a GT45 or two feeding the 6.0 some extra air would make for a really sweet rig to drag my Pontiac race cars around. I have one more BBC to sell, they just won't do what I want them to do. Make torque on minimal fuel, they are quite thirsty for the tq output... then all the broken valve springs, bent pushrods, etc... not my thing.
You would probably like the 394Ci 6.4L stroker in my truck Running the stock 300CFM Eagle heads with 11:4:1 compression, 6.4l variable runner intake, 233/246 112LSA 5degrees of advance, 3,600 stall 3.55 gear 6speed. She makes right at 500RWHP, be a lot more with a new 8Hp70, in my 5,200Ib 4X4. This motor was blue printed and purposely built to make lots of torque and hp for the street, she is a blast. I’m definitely near the limit of the heads, but the getup is fun!
@@SweatyFatGuy It's funny how Ma Mopar kept chugging out 413's for industrial use when their muscle cars had 383-400-440 options--guess they got their R&D money out of the 413. No doubt, your LS swap would do well on an anemic gas chugger (in "who cares" news, I finally broke down and ordered up yet another cheap-o 8x12 shed for the property, guess i'll be accumulating engines again). too bad about your rats not doing what you want, what combos are you running and is that why you're breaking that canted valve setup?
$ per HP is what that boils down to. How that impacts ones particular wallet, and what the intended use really is. Flow numbers vs intake CC volume would be the interesting thing. A smaller port with a better shape, flows more, than a bigger port that sucks. And will therefore make more power across the board, and with better throttle response because the port velocity will be far greater. Another aspect of this is the amount of demand being placed on the port. A 454 vs a 540 vs a 598 etc will respond differently with one head to the other.
He as a ford guy and watching you test all this stuff I gotta say there’s a big difference between top quality mfg’s let alone cheap offshore stuff. No doubt about it. The good heads are worth it.
AFR makes a good head. I have a set of 305's on what started out as a 454, now 532(different bottom end.) I'm curious if the 265's have the same fitment issues that the 305's do. By raising the exhaust port, it made headers and spark plugs much more difficult. I have a street 427 that has a set of 990's on it, HUGE ports, and ported out on top of that prior to my ownership. I've thought of changing them out for a set of AFR 265's. This video proved why.
Get rid of 990’s they’ve had their time. AFR’s ovals are killer. I put a set of 300 AFR’s on my 572. Made 807 hp And 739 ft/lbs. insane acceleration. Pulled my chevelle along like it weighed nothing.
Richard I've been waiting for you to use this kind of combo on your big block Chevy 468. I feel like the average street guy this is the most common big block Chevy they're going to do somewhere in this same realm I'd like to see you do something a little better than the super cheap pro comps which are everyone knows are junk.... how about maybe you could do a AFR 335 as cast enforcer head because it is an offshore Chinese head casting. Compared to maybe a promax 317 which is the as cast offshore version of the AFR 315. And then do it with an actual AFR 315. It would just be cool to see offshore AFR against onshore AFR on this motor... same cam... same compression... just different heads
AFR worth the money if u got it id probably buy AFR even if i had to wait to save the extra doe. But id like to see speed master heads with port work done to them. Maybe wouldn’t make much difference idk. It’s crazy how much more power AFR actually make. Great stuff Thanks
The speedmasters are basically good for a weight reduction. The AFR will be much more fun to drive, all the time. They'll probably get better mileage too. The cheap ones can't even be ported to match the AFR...maybe with lots of epoxy.
I agree, the mean reason I bought the cheap BBC aluminum heads, that and the local machine shops were quoting me outrageous prices for a stock cylinder heads rebuild.
My uncle taught me you want to have the smallest intake Port cc that flows the most air (cfm) When comparing cylinder heads. Like you said bigger isn't always better
So the speedmaster heads are great for mild street builds just to get the weight off. Or they're great if you have a short block and no heads at all, vs finding a set used and running them thru the machine shop, then buying springs and hardware. Spending more makes sense if you have specific power goals or other heavy duty requirements
one more factor, is for a load bearing engine. Aluminum is going to give you some detonation cushion when you run into headwind on a steep hill (theoretically). I'd sure take one of these over running a peanut port thru a machine shop, as you said.
I read online (grain of salt) that people recommend taking the Speedmaster heads to the money mill, just to make sure they won't drop a seat or valve. I bought a pair of clean peanut ports for $200. Rotator eliminators and a grind of the valve guides for extra retainer clearance and I'm in business. $400 in my heads, no machine shop needed.
@@AustinRBa they're even better if you do a mild home port job. There's power hiding in those much overlooked peanut ports. Plus, they are great for doing burnouts! 😁 They just don't make much power beyond 5500 rpm. Which is perfect for stop light to stop light fun. Hint...ZZ502 cam with PP heads. 👍
@@AustinRBa it helps to know how to diagnose a used head at home. checking to see if the deck has been milled or angle milled before (which means your intake may not fit, and milling that might affect the distributor's clamping down to it), checking for cracks (common on Vortecs and Magnum heads), pressure checking, knowing if the valves are sealing at the seat and at their tips, etc. it always surprises me how many parts sellers won't clean their parts and get some extra cash. I've landed some sloppy, greasy looking stuff for pennies on the dollar--worth taking a chance at those prices.
@@msh6865 agreed, there's good videos online on how to port a head, and some of us don't mind an engine that gasps for breath at 6,000 rpm. great for pulling trailers or just follow 1980's technology and give 'er an economy rear axle and a granny first transmission.
The question you should ask will this engine make more horsepower on boost, yes run the same setup on a single turbo or twin on each heads. To see if the extra 59hp gain will it double or make more horsepower vs the speed master head.
I’m curious about the smaller port Speedmaster Heads and how they might stack up against the AFR? At 305 they are not much bigger than the Edelbrock which are at 290. I’m also curious how the Edelbrock “High Compression” heads compare to the factory Vortec heads? They both have a combustion chamber volume of 100cc’s.
I'd love to see a Profiler v. Chinese head test. After all, most of the Chinese knock offs are a knockoff of the Profiler. And as someone said below, it's the work done on the head after the casting that makes all the difference. Another thing, replace the springs, retainers and valves to 'comparable' and that price difference really isn't double. Basically, you're getting AFR or whoevers CNC port program for cheap. And lastly, you can't compare a 335 head to a 265 head - they're different heads for different builds.....
This would be great if we all was building 496 not all of us have that kind of cash the 119 cc chamber is ok when you have a five gallon bucket for a pistons but I have a 402 with a speed pro pistons 29715-12A-B STD and when you do the math on the compression it comes out to 7.5-1 I’m not trying to rotate the earth under acceleration but I would like the wait reduction just want a oval port I wish you would look at the Bow Tie heads they are oval ports and a 110 cc chamber but since they put the cool Bow Tie emblem on the exhaust ports that added a big $ kinda wondering if they are worth it for me or is there a cheap knock off I know that the valves usually don’t seal but I own all the equipment to fix that been down that road before
For a hipo street 454 up to 7k rpm use a set of 049's with a 2.19 intake and some mild porting and your good to go. A proven combo but yeah they do weigh 80lbs more than aluminum heads.
Hey Richard, love your stuff. I would be really interested to see a BBC Head comparison between AFR 265/315's etc vs the Enforcer item, in terms of bang for buck
But now the real test on the Speedmaster heads would be comparing them to factory rec port heads on the same combination in a 540 cu in BBC. I bet the perform a little better with more demand from the engine. Also, you can open the bowls to 100% of the valve size, the throats to 91%, and widen and flatten the short side radius a bit and pick up some more airflow.
The rec port heads did work pretty well, but the problem from the factory was always that they used the wrong cam in the rec port engines. The cams they used stock usually being a single pattern, or only a small split between intake and exhaust duration, work pretty well with the factory ovals that had a pretty good I/E flow ratio. The rec ports tho, they needed a better exhaust port to really work like they should have. One way to compensate is with more exhaust duration that really does help them out. The OE rec port heads really need a cam with an exhaust lobe about 15* bigger than the intake to work well without port work. GM started to figure that out I think in the late 70s or 80s, when the 454 HO came with a 211/230 cam in it, to work with the 990 heads. It worked pretty well, considering it was only like 8.8:1 compression too.
I for one would be (and do) pay higher $$ products for my vehicles. Engines are no exception. You usually get what you pay for, for performance. Gotta pay to play. And durability I think comes into play as well
If I were not putting any money into power adders, it would make sense to spend it on the better heads. However, if putting a turbo or blower to it ....
another thing to consider, how much was the valve job and upgraded springs on the cheaper speedmaster heads? Id love to see the final prices on the different sets of heads
Guy's, first of all, I haven't fooled with BBC engines for 50 years and I don't know my butt from a hole in the ground, need to say that up front. I do build a few SBC Stroker engines with decent results. I have been asked to build a BBC for an 80s 4 WD truck. I can't get the information that I would like so this is by the seat of my pants. I have a 454 4 bolt and peanut heads and throttle body. I haven't heard it run and can't start it the way my test stand is set up, so the first thing is an intake and carb. I was reading about Skip White from Kingsport, TN. He took a 454 and built a 496 stroker with a 4.25" stroke and bored .060 over, 218cc piston and cam along with the "As-Cast" AFR 335 Aluminum head. He used a Wieand Warrior intake and Holley carb. On the Dyno the engine the engine produced something like 672 HP. He has the stroker kit and AFR heads advertised at 650HP. For both the stroker kit and heads is about $3800. Of course there are other incidentals that I will incur like the Warrior intake, carb and timing gear and cam. This should be a Bad-A$$ engine in the truck. Got no idea what the truck will be used for. I was going to build a 383 Stroker for it. He just told me he wanted something "Stout". Any thoughts? BTW, I want to hear it run for my own reasons. When I pulled the intake I found both pushrods on #7 cylinder badly bent with one of the lifters for that cylinder lying in the lifter valley. Also found probably 6-8 other pushrods badly bent and one of the pushrod guides for #7 Cylinder broke in half. Got no idea why.
The quandary becomes even more perplexing when you realize that Speedmaster has a 40% off sale every Black Friday weekend, making those $1250 heads come in at $750 including shipping. Best is to buy them bare for even less and put better valves and springs in. I don't recall AFR's or any of the other "domestic" brands ever being on sale.
Velocity is a big factor with the afr heads. I wonder how the runner sizes would react with boost. That would Be a good comparison. Smaller runners are better for n/a
the power output under boost is a function of the power output na x boost (as a function of change in atmospheric pressure minus parasitic losses) runner size would not be a factor-the afr heads would also make more under boost
I’d like to see the same engine with a set of AFR Rec port 305’s just for curiosity. I wonder how much could be gained if you ported the Pro Comp oval ports. Great content as always 👍
I wonder how the edelbrock rectoval heads stack up. Side note: I didn't have much luck with the milodon marine oil pan & I'm not the only one. Rumor is that they didn't put much r&d into it due to being a small market. I went with a Stef's fabricated pan to fit my hull and it worked perfectly.
I wonder what a set of bigger AFR heads would do like the 290’s. The 265 AFR’s are for towing looking at the catalog on their website. The offer up to 385cc tho😮
I was interested in reliability as I want a very reliable BBC for my Crownline 24' boat. The bit of extra power just not worth it to me but what about reliabilty? The same??
The expense comes from CNC machining! If you take your low buck heads and have them ported by CNC and you probably be pretty close to HP from high dollar heads! But perhaps the money value of being "CHEAP" isn't so cheap after you do all of the machining!
I think a lot depends on if it's a street car or quarter mile car and what gears how many times does a street car actually use 5 to 6 thousand rpms richard have you done a video on how much power port matched intake gains on performer rpm manifold
Yeah, my junkyard mk-iv 454 Combo with factory iron #781 casting oval Port heads unported, stock size 2.06"intake and 1.72" exhaust valves custom grind solid roller cam combo makes more Power from 2500-6000 rpm than my 10 second quarter mile small block combo, it's all over by 6500rpm though. There is more init, but I don't have the money for anymore testing.and I doubt you will do better than that for unported factory oval Port heads and a given amount of money anyway.
For a budget deal, I’d install larger valves and some bowl work on the peanuts. The speedmaster have too many quality horror stories. For similar money you could have similar horsepower without worrying about dropping a valve seat
The afr is best, no doubt. If you can afford it yea it’s worth it. If not then either the Chinese stuff and add a 150 of nitrous and go. Chances are something better than those ages will come along later anyway.
Richard, in your experience, how large of port volume (on AFR type BBC head!) can you go before it cost a “significant” amount of low end torque? If investing on a quality set of heads is it wise to invest some additional dollars for some “just in case” future power mods??
You got more power from the AFR head because of intake port velocity from a stock bore. Test apples to apples. Let’s see what some afr 335s do in comparison to some bravo or assault Chinese 345s
I guessing the AFR heads were fully CNC ported and finished, Vs the Speed masters were as cast. I bet there would be an easy 30 hp in the Speedmasters by simply cleaning up the valve pockets and bowls
@@richardholdener1727 I get that. I wonder why they made 50 less hp. Has to be a reason. Either a major choke point in the bowls or god awful port configuration. Or both
I wouldnt argue that the afr would still make more power, but it looks like you had a valve control issue with the speedmaster heads. Probably make another 20 or 30 with different springs
Maybe I'm missing something, but I don't see anything indicating a valve float condition until MAYBE 6100rpm. And the torque curve was already well on its way down.
@@AustinRBa the way the power flattens out compared to the afr i believe the spring may possibly starting to loose conrol. Then finally does and you get that crash at the end. The peanut port head most likely kept the oem 3/8 heavey valve and the speedmaster had Chinese springs. I think neither of the prior heads had enough spring for the cam and valvetrain weight. If they did they would be shaped closer to the afr's but not as high just not as high.
Would like to of seen the smaller oval speedmaster heads tested, kinda a better match to the other 2 heads you are comparing them to. 320cfm is allot of air for that cubes...
Maybey I missed it? Did you mention what compression each of these heads made? Or the shape of combustion chamber?? I would want to know how much that played a roll in the out put differences?
Why not test everything down to 2000-2500 rpm? A lot of us aren’t making engines to rev to the moon we just want max torque way low for towing or off-roading it’s hard to figure out how to build something use full when everything is how to make 1000 HP at 8000 RPM. I do appreciate this video finally showing some more practical rpm ranges thank you
i’ve got a couple different versions GEN 4and a GEN 5 both have peanut port heads my gen4 has an Edelbrock air gap with a 870 demon the gen5 was a TBI a motor as you know we put the same induction as a gen 4 on and made less power and torque i’ve run compression checks on both motors, give or take 4or5 psi cylinder compression on both engines range 200-205. maybe someone can enlighten me where there any differences on a peanut port heads did they change the runner Heights or angles? Have you ran into discrepancies like this Richard?
I've been a firm believer that air speed velocity trumps port volume for horsepower gains anyday. I've seen it far to often with engine combinations I've put together. If there is not enough engine to use the supplied air, it's just wasted. My theory behind that is that the air/fuel mixture just seems to tumble through the port, instead of flowing smoothly, therefore hurting efficiency. What are your thoughts on that @Richard Holdener? Have you done any testing on that? I'd like to check out the video if you have.
@@georgeashmore9981 I agree with you on velocity. Cam duration plays a role when using smaller ports too. Keep the velocity up for lower rpm, heavy street cars.
imagine the same shape curves but double the hp at 14 psi on both of them. So the brodies were 55 better then they would be roughly 110hp better at 14 lbs boost.
It's not just the peak HP and peak torque that matters, it's area under the curve.
And, as Darin Morgan says, port velocity makes engines accelerate vehicles.
Exactly, the AFR heads is the personification of this. I had a feeling that the cast heads were dropping compression and losing a ton of velocity.
I've used the AFR 265's and Brodix Race Rite 270's on 496's and they were absolute monsters. One was a '70 Nova with a 2.73 gear and the other a 68 Chevelle SS with 3.73's. The 2.73's were fine. That big motor didn't care what gears the car had. The 3.73's were just ridiculous. No traction in any gear.
I love the Race Rite heads and even more so on a 496.
Put 0n slicks
or do what I did, mini tubs, back halfed and big meats on my Nova. Mine has original L89 heads BTW
I'm still impressed with the performance of the peanut ports. I remember when Chevy came out with the SS454 pick up truck back in 1990. Everyone said it was totally lacking in performance all due to the peanut port heads. Guys were doing top end swaps and were getting good performance from them but of course that also included a new cam. After watching Richard dyno test peanut ports several times the only conclusion is that they are really decent heads. I have been a long time Pontiac guy and I can tell you that stock high performance D-port Pontiac heads will not make 512 on a 455. 450 is about all you will ever see and that's with a single plane intake and really big cam. And these are heads us Pontiac guys always considered pretty good.
This convinced me to keep mine on my 91 3/4 ton truck.
What is your opinion on afr 265 vs afr 290 heads on a 496 engine?
I am always interested in BBC heads. Like you said, we were all "conditioned" to believe that rec ports are the way to go for performance. I ran the stock ovals for years. Then I finally got to buy some closed chamber rec ports and intake from a '68 427. I am not sure I am much better off, at least on a street car. On my next engine I think I will go oval port.
I bought a '70 Corvette back in the mid '90's. It had a '70 LS6 in it that was totally stock. It ran great but I sold the top end off the engine and built a set of 049 oval ports using John Lingenfelter's advice from the pages of Hot Rod magazine. My quarter mile times went from 12.90's to 12.30's and the car was more docile during street driving. The short block, including the cam was unchanged. Performer RPM intake instead of the stock GM, but the same 850 Holley double pumper that was on the LS6 and the same factory Big Block Corvette iron exhaust manifolds. Oddly enough my trap speeds were similar, 114 with the oval ports and 112 with the rec ports. I guess the bigger ports were coming on strong on the big end.
I think it would be really interesting to test factory Chevy rectangle port vs. factory Chevy oval port heads on the same engine back to back. You could find some late 1960's closed chamber oval port heads and test them on your L78 396 and LS6 454 engines using a vintage Edelbrock C-396 oval port dual plane high rise intake.
Another interesting test IMO, would be to test your L78 engine stock with headers and then blueprint and modify it to the 1967 NHRA rule book for "stock" class racing and dyno. Then modify for "super stock" class racing and dyno.
Quality pays for itself over time.
The 265 AFR's are benefiting from the higher intake velocity that you get from a smaller port area. That's why peanut port heads hold their own up to about 5000 rpm. Keeping intake velocity up makes power and torque.
The Speedmasters aren't bad heads. Their ports just have too much area for this test. Air entering the head slows down. I'd love to see a Speedmaster 270 aluminum oval port head hit the market. Lots of guys would run them on the street if for no other reason than to take some weight of the front end.
Great test!
Exactly, the Speedmaster head would be more befitting on something like a 632. It would have better port velocity on a much bigger engine.
tbh the peanut ports wouldn't be bad at all on a street cruiser/tire burner.
It looks like the springs were giving up around 5500 on the procomp heads? Power goes flat and then dives… if you did a little porting cleanup on the procomp would that do much or maybe they already did that from the factory?
It has to do with VELOCITY.
The bigger port is too big, which SLOWS THE VELOCITY, this is not good for power.
Port design also has a significant impact on flow, especially with the big block Chevy, which is affected much more than most engines by this.
Speedmaster heads work well for mild street/show cars, you can easily get close to their price just having a set of stock heads rebuilt.
Here are some data points from 1967-1968 NHRA drag times for rectangle port 396/375hp cars in A/S, SS/C and SS/D classes versus oval port 396/325hp cars in SS/E and SS/EA classes:
From 1967 races:
1967 SS396/375 Camaro, Bill Thomas, NHRA SS/C, 4sp, 3,508 lbs: 11.85 @ 119.86 mph
1966 SS396/375 Chevelle, Wally Booth/Dick Arons, SS/D, 4sp: 11.80 @ 119.36 mph
1967 SS396/375 Camaro, Bill Jenkins, SS/C, 4sp: 11.51 @ 115.97 (not full pass)
1967 SS396/325 Camaro, Dick Arons, SS/EA, TH400, 3,217 lbs: 11.63 @ 118 mph
1966 SS396/375 Chevelle, Mike Hoover, A/S, 4sp: 12.01 @ 117.18 mph
From 1968 races:
1968 SS396/375 Camaro, Kelly Chadwick, SS/C, 4sp: 11.30@124 mph
1968 SS396/325 Camaro, Jim Baker/Bill Thomas, SS/EA, TH400, 3,308 lbs: 11.67 @ 120.95 mph
1968 SS396/375 Nova, Ed Hedrick/Jenkins, SS/D, 4sp: 11.30 @ 123.38 mph
1967 SS396/375 Camaro, Bill Jenkins, SS/C, 4sp: 11.18 @ 124.48 (also ran 11.05, Jenkins claimed 540hp on dyno)
1968 SS396/325 Camaro, Christie Fisher, SS/E, 4sp, 3,250 lbs: 11.55 @ 121 mph
1968 SS396/375 Camaro, Dale Armstrong/Dana, SS/C, 4sp., L89 alum. head, 3,162 lbs: 10.61 @ 128 mph
For NHRA SS class, cars could use any stock appearing single 4 bbl intake and any flat tappet cam, but must use stock carb so SS/E and SS/EA 325hp cars ran with stock Quadrajet. Also, in 1968, NHRA factored iron head L78 396 at 425hp and factored aluminum headed L78/L89 at 435 hp. Per NHRA, shipping weight for L78 car was 3,235 lbs and shipping weight for L78/L89 was 3,162 lbs for SS/C class. Dale Armstrong's Dana '68 L78/L89 Camaro was basically a 396 cid L88 since it ran L88 heads, L88 intake with gutted plenum and 2nd design L88 cam.
Long ago I had a 461 bbc with closed chamber oval port heads. Was ~ 12:1 compression and a street car that made 512 hp. Got tired of mixing expensive race fuel with pump gas. Switched to open chamber 990 square ports and a different intake, and lowered the compression to ~ 10.5:1. Then on pump gas it made 573 hp, a 61 hp gain. Oval wasn’t the best in my situation when using factory cast iron heads. The car picked up considerable et as well.
Yes it's absolutely worth it!
Have you ever run the 100cc heads edelbrock makes I believe they are marine heads but always worth looking into
Availability on good aluminum heads comes into play these days also, always like the head comparisons
My old cast iron 702 heads are working really good for me. Closed chamber oval ports with bigger valves and mild porting on the SSR and chamber walls plunge cut to unshroud the intake valves. With 9.5:1 CR and a small Clay Smith HR 221/235 @0.050” o.577” lift and a 3310 VS Holley. When the back barrels open it blows the tires off. These hemis, camaras and mustangs gonna learn not to mess with the patina ‘72 C10 in SW Houston....😂😂😂
Would be interesting to see how AFR's as cast heads would perform compared to speedmaster's.
The ProComp/Speedmaster heads aren't mostly bad. If you're good at porting and cleaning up the intake port they're worth the money to buy them bare, second hand for $300-400 a set. Everything else about the heads in a built config is garbage. Springs, seals, valves, all garbage. The biggest issue is the crap porting and the massive valve seat overhang. Flow numbers aren't everything, how clean they flow is just as important. If you are good with a grinder you can get in there and clean most/all of that up. Just have to be real careful when cleaning up the valve seat overhang/lip to not get in to the sealing surface. Friend and I did a similar test between Speedmaster's and TrickFlow heads on a SBM 318. After cleaning up the Speedmaster's and building them with good parts they were only 9 HP under the TrickFlow's with very similar torque and power curves.
Port velocity I guess is what’s more important on a smaller engine with smaller heads
Great test, I always enjoy a test showing that bigger is not necessarily better.
I don't know how often resale comes into play for most hot rod folk with their car / engine parts but the AFRs come out ahead here too for me and likely most.
Is all about flow. CC size of the chambers isn’t as important as the flow. It’s still important, just not as important as manufacturers want you to believe.
Why a 950cfm carb? That’s way more than that build will utilize.
Hey Richard, appreciate 1 more for the library, Thanks!
Not all of us have big budgets for cylinder heads. On Summit you can get bare "as cast"heads, it would be interestibg to see a build of those to get them running well. Id imagjne they would need to be completely gone through but maybe save a few bucks in the long run
That was a great test! Who is not going to pick a bigger port for less money right? Unless it’s a budget breaker I would spend the money on the AFRs. Fifty hp is just too much to leave on the table and I think you get better quality overall and probably better reliability as well. I have seen this on other parts as well. For example has anybody ever seen a test where a Performer RPM intake does not make more power than seemingly identical knock offs?
Why did you do a valve job on the new speedmaster heads?
they needed it
Are you saying that speedmaster is poor quality out of the box?
I didn’t hear you mention chamber/compression ratio differences. The factory heads vary all over, and you did flash the 112 cc up for the AFRs. The CR can move the meat of the torque curve up or down quite a bit. Those AFR ovals seem to work really well. Thanks, Richard!
compression doesn't usually change where the motor makes power-it adds consistently through the curve
@@richardholdener1727 I agree. My “up or down” was intended to refer to lb-ft, not rpm. My bad for being unclear.
With the engines I run, this is easy, we tend to go with CFM at various lifts to tell what we should run rather than port volume. I like to chase torque rather than HP, because most of my engines live under 6000rpm, so port velocity is far more important to me than port volume or cross section. With Pontiac engines and only having one Chy-na budget head available, we usually port all of them anyway. Who does the porting makes a difference.
A friend of mine has an engine of the same CI and compression, but he is making less power because of the port work, and supposedly his heads flow more. However what mine flow at .550 lift his flow at .700.
So many interesting parameters and effects of the various engine designs, they're more than just air pumps, though you can expect certain things that are similar across all of them. The difference is where they make their power and what the ultimate limits are. Thats why I like to see what the other engines do, what the torque curves look like, and what effects changes have.
I really like the grunt engines though, even if they are harder to get to hook up.
agreed--focus on what a head flows at full valve lift, and you are aiming for the shortest duration of time the entire valve is in motion. Focus on lower valve lift flow, and you gain when the valve races to full lift and then gain when its closing. Most "dyno queens" don't get this, they just want to brag about a big number (though it's too bad Speedmaster didn't create smaller ports with thick walls to let the buyer port to their needs). Also, port flow rating can change depending on how small a bore the head sits on due to cylinder wall shrouding--the average rat needs that .060" overbore. and then there's combustion design--you cram a bunch of air in but the fuel droplets separate and you get a lousy burn.
were i building a "cheap" motorhome powerplant, i'd go with the Speedmaster setup over cast iron and enjoy the potential detonation cushion. But BDFC of the smaller ports might factor in.
@@albertgaspar627 I have a 1971 Travco RV I have been thinking about swapping an engine into. It has a good running but anemic 413 Chrysler in it right now. man does that thing drink the gas. I have several 6.0 LS engines from rusted out trucks, and some 4L80 transmissions, so it stands to reason that a Truck Norris cam with a GT45 or two feeding the 6.0 some extra air would make for a really sweet rig to drag my Pontiac race cars around.
I have one more BBC to sell, they just won't do what I want them to do. Make torque on minimal fuel, they are quite thirsty for the tq output... then all the broken valve springs, bent pushrods, etc... not my thing.
the afr head flow 20-25 cfm more at each lower lift that the speed heads
You would probably like the 394Ci 6.4L stroker in my truck
Running the stock 300CFM Eagle heads with 11:4:1 compression, 6.4l variable runner intake, 233/246 112LSA 5degrees of advance, 3,600 stall 3.55 gear 6speed. She makes right at 500RWHP, be a lot more with a new 8Hp70, in my 5,200Ib 4X4. This motor was blue printed and purposely built to make lots of torque and hp for the street, she is a blast. I’m definitely near the limit of the heads, but the getup is fun!
@@SweatyFatGuy It's funny how Ma Mopar kept chugging out 413's for industrial use when their muscle cars had 383-400-440 options--guess they got their R&D money out of the 413. No doubt, your LS swap would do well on an anemic gas chugger (in "who cares" news, I finally broke down and ordered up yet another cheap-o 8x12 shed for the property, guess i'll be accumulating engines again).
too bad about your rats not doing what you want, what combos are you running and is that why you're breaking that canted valve setup?
I feel like you made this video based on our last exchange of emails Richard! Lol awesome
Totally worth the cost, even for a mild street machine. Best way to save money on BBC heads is use GM castings.
my issue with the cheap heads isn't if they offer the power, but if they simply actually work, as in seal, don't crack, are not warped, line up, etc.
$ per HP is what that boils down to. How that impacts ones particular wallet, and what the intended use really is. Flow numbers vs intake CC volume would be the interesting thing. A smaller port with a better shape, flows more, than a bigger port that sucks. And will therefore make more power across the board, and with better throttle response because the port velocity will be far greater. Another aspect of this is the amount of demand being placed on the port. A 454 vs a 540 vs a 598 etc will respond differently with one head to the other.
He as a ford guy and watching you test all this stuff I gotta say there’s a big difference between top quality mfg’s let alone cheap offshore stuff. No doubt about it. The good heads are worth it.
Another great test video!
I would like to see a test of the flotek 290 oval vs the 265 afr.
I wanna say this was from my comment on your last video, but thank you for making this! My gen 6 might have hope yet!
AFR makes a good head. I have a set of 305's on what started out as a 454, now 532(different bottom end.) I'm curious if the 265's have the same fitment issues that the 305's do. By raising the exhaust port, it made headers and spark plugs much more difficult. I have a street 427 that has a set of 990's on it, HUGE ports, and ported out on top of that prior to my ownership. I've thought of changing them out for a set of AFR 265's. This video proved why.
Get rid of 990’s they’ve had their time. AFR’s ovals are killer. I put a set of 300 AFR’s on my 572. Made 807 hp
And 739 ft/lbs. insane acceleration. Pulled my chevelle along like it weighed nothing.
Richard I've been waiting for you to use this kind of combo on your big block Chevy 468. I feel like the average street guy this is the most common big block Chevy they're going to do somewhere in this same realm I'd like to see you do something a little better than the super cheap pro comps which are everyone knows are junk.... how about maybe you could do a AFR 335 as cast enforcer head because it is an offshore Chinese head casting. Compared to maybe a promax 317 which is the as cast offshore version of the AFR 315. And then do it with an actual AFR 315. It would just be cool to see offshore AFR against onshore AFR on this motor... same cam... same compression... just different heads
AFR worth the money if u got it id probably buy AFR even if i had to wait to save the extra doe. But id like to see speed master heads with port work done to them. Maybe wouldn’t make much difference idk. It’s crazy how much more power AFR actually make.
Great stuff
Thanks
The speedmasters are basically good for a weight reduction. The AFR will be much more fun to drive, all the time. They'll probably get better mileage too. The cheap ones can't even be ported to match the AFR...maybe with lots of epoxy.
I agree, the mean reason I bought the cheap BBC aluminum heads, that and the local machine shops were quoting me outrageous prices for a stock cylinder heads rebuild.
What about the same test but fully ported and gasket matched heads? One cheap, one expensive.
My uncle taught me you want to have the smallest intake Port cc that flows the most air (cfm) When comparing cylinder heads. Like you said bigger isn't always better
So the speedmaster heads are great for mild street builds just to get the weight off.
Or they're great if you have a short block and no heads at all, vs finding a set used and running them thru the machine shop, then buying springs and hardware.
Spending more makes sense if you have specific power goals or other heavy duty requirements
one more factor, is for a load bearing engine. Aluminum is going to give you some detonation cushion when you run into headwind on a steep hill (theoretically). I'd sure take one of these over running a peanut port thru a machine shop, as you said.
I read online (grain of salt) that people recommend taking the Speedmaster heads to the money mill, just to make sure they won't drop a seat or valve. I bought a pair of clean peanut ports for $200. Rotator eliminators and a grind of the valve guides for extra retainer clearance and I'm in business. $400 in my heads, no machine shop needed.
@@AustinRBa they're even better if you do a mild home port job. There's power hiding in those much overlooked peanut ports. Plus, they are great for doing burnouts! 😁
They just don't make much power beyond 5500 rpm. Which is perfect for stop light to stop light fun.
Hint...ZZ502 cam with PP heads. 👍
@@AustinRBa it helps to know how to diagnose a used head at home. checking to see if the deck has been milled or angle milled before (which means your intake may not fit, and milling that might affect the distributor's clamping down to it), checking for cracks (common on Vortecs and Magnum heads), pressure checking, knowing if the valves are sealing at the seat and at their tips, etc.
it always surprises me how many parts sellers won't clean their parts and get some extra cash. I've landed some sloppy, greasy looking stuff for pennies on the dollar--worth taking a chance at those prices.
@@msh6865 agreed, there's good videos online on how to port a head, and some of us don't mind an engine that gasps for breath at 6,000 rpm. great for pulling trailers or just follow 1980's technology and give 'er an economy rear axle and a granny first transmission.
Those AFR heads are wild for only being 265cc.
The question you should ask will this engine make more horsepower on boost, yes run the same setup on a single turbo or twin on each heads. To see if the extra 59hp gain will it double or make more horsepower vs the speed master head.
it will
I’m curious about the smaller port Speedmaster Heads and how they might stack up against the AFR? At 305 they are not much bigger than the Edelbrock which are at 290. I’m also curious how the Edelbrock “High Compression” heads compare to the factory Vortec heads? They both have a combustion chamber volume of 100cc’s.
I'd love to see a Profiler v. Chinese head test. After all, most of the Chinese knock offs are a knockoff of the Profiler. And as someone said below, it's the work done on the head after the casting that makes all the difference. Another thing, replace the springs, retainers and valves to 'comparable' and that price difference really isn't double. Basically, you're getting AFR or whoevers CNC port program for cheap. And lastly, you can't compare a 335 head to a 265 head - they're different heads for different builds.....
This would be great if we all was building 496 not all of us have that kind of cash the 119 cc chamber is ok when you have a five gallon bucket for a pistons but I have a 402 with a speed pro pistons 29715-12A-B STD and when you do the math on the compression it comes out to 7.5-1 I’m not trying to rotate the earth under acceleration but I would like the wait reduction just want a oval port I wish you would look at the Bow Tie heads they are oval ports and a 110 cc chamber but since they put the cool Bow Tie emblem on the exhaust ports that added a big $ kinda wondering if they are worth it for me or is there a cheap knock off I know that the valves usually don’t seal but I own all the equipment to fix that been down that road before
For a hipo street 454 up to 7k rpm use a set of 049's with a 2.19 intake and some mild porting and your good to go. A proven combo but yeah they do weigh 80lbs more than aluminum heads.
049 heads hard to find these days
Hey Richard, love your stuff. I would be really interested to see a BBC Head comparison between AFR 265/315's etc vs the Enforcer item, in terms of bang for buck
The more port velocity with smaller ports is key.
But now the real test on the Speedmaster heads would be comparing them to factory rec port heads on the same combination in a 540 cu in BBC. I bet the perform a little better with more demand from the engine. Also, you can open the bowls to 100% of the valve size, the throats to 91%, and widen and flatten the short side radius a bit and pick up some more airflow.
The rec port heads did work pretty well, but the problem from the factory was always that they used the wrong cam in the rec port engines. The cams they used stock usually being a single pattern, or only a small split between intake and exhaust duration, work pretty well with the factory ovals that had a pretty good I/E flow ratio. The rec ports tho, they needed a better exhaust port to really work like they should have. One way to compensate is with more exhaust duration that really does help them out. The OE rec port heads really need a cam with an exhaust lobe about 15* bigger than the intake to work well without port work. GM started to figure that out I think in the late 70s or 80s, when the 454 HO came with a 211/230 cam in it, to work with the 990 heads. It worked pretty well, considering it was only like 8.8:1 compression too.
any bigger cam will add power-and the rec port heads responds to cams the same as cath port heads-see that video
@@richardholdener1727 bigger on the exhaust lobe is what I was getting at tho, the rec ports seem to respond well to a larger exhaust lobe
I for one would be (and do) pay higher $$ products for my vehicles. Engines are no exception. You usually get what you pay for, for performance. Gotta pay to play. And durability I think comes into play as well
If I were not putting any money into power adders, it would make sense to spend it on the better heads.
However, if putting a turbo or blower to it ....
I’ve got a 454 im trying to wake up, and it’s looking like AFR is the way to go.
Ive got a set of 781 oval port heads that I can’t decide whether or not I want to use. Im sure they’ll make power but man are they heavy!
another thing to consider, how much was the valve job and upgraded springs on the cheaper speedmaster heads? Id love to see the final prices on the different sets of heads
What about a gen 6 head with the 100cc combustion chamber vs the afr 265 head?
265 afr would be lots better than stock gen 6
@@richardholdener1727 I bet it would be an upgrade over a peanut port at least. Compression ratio should get a little bump at minimum
Guy's, first of all, I haven't fooled with BBC engines for 50 years and I don't know my butt from a hole in the ground, need to say that up front. I do build a few SBC Stroker engines with decent results. I have been asked to build a BBC for an 80s 4 WD truck. I can't get the information that I would like so this is by the seat of my pants. I have a 454 4 bolt and peanut heads and throttle body. I haven't heard it run and can't start it the way my test stand is set up, so the first thing is an intake and carb.
I was reading about Skip White from Kingsport, TN. He took a 454 and built a 496 stroker with a 4.25" stroke and bored .060 over, 218cc piston and cam along with the "As-Cast" AFR 335 Aluminum head. He used a Wieand Warrior intake and Holley carb. On the Dyno the engine the engine produced something like 672 HP. He has the stroker kit and AFR heads advertised at 650HP. For both the stroker kit and heads is about $3800. Of course there are other incidentals that I will incur like the Warrior intake, carb and timing gear and cam. This should be a Bad-A$$ engine in the truck. Got no idea what the truck will be used for. I was going to build a 383 Stroker for it. He just told me he wanted something "Stout". Any thoughts?
BTW, I want to hear it run for my own reasons. When I pulled the intake I found both pushrods on #7 cylinder badly bent with one of the lifters for that cylinder lying in the lifter valley. Also found probably 6-8 other pushrods badly bent and one of the pushrod guides for #7 Cylinder broke in half. Got no idea why.
The quandary becomes even more perplexing when you realize that Speedmaster has a 40% off sale every Black Friday weekend, making those $1250 heads come in at $750 including shipping. Best is to buy them bare for even less and put better valves and springs in. I don't recall AFR's or any of the other "domestic" brands ever being on sale.
Lingenfelter showed this back in the '90s making big numbers with peanut and oval port heads.
Have a link to his builds ?
👍👍👍 thanks Richard
right on time, again!
Velocity is a big factor with the afr heads. I wonder how the runner sizes would react with boost. That would
Be a good comparison. Smaller runners are better for n/a
the power output under boost is a function of the power output na x boost (as a function of change in atmospheric pressure minus parasitic losses) runner size would not be a factor-the afr heads would also make more under boost
A little off topic but will a edelbrock performer oval port head from a mark IV fit on a gen v block with a gen V head gasket?
not sure
I’d like to see the same engine with a set of AFR Rec port 305’s just for curiosity. I wonder how much could be gained if you ported the Pro Comp oval ports. Great content as always 👍
would be interested to see the world products merlin 3 320cc heads since they are pretty inexpensive
This test reminds me of the B-head 96-98 Vs the C-head 99-04Cobra.
I wonder how the edelbrock rectoval heads stack up.
Side note: I didn't have much luck with the milodon marine oil pan & I'm not the only one. Rumor is that they didn't put much r&d into it due to being a small market. I went with a Stef's fabricated pan to fit my hull and it worked perfectly.
stef's is good stuff
I wonder what a set of bigger AFR heads would do like the 290’s. The 265 AFR’s are for towing looking at the catalog on their website. The offer up to 385cc tho😮
My kinda tow engine!
Would have love to see them vs the larger peanut port (96-00)
96-00 are the Vortec heads. They are large oval, just not quite as large as MKIV ovals. 99cc chamber won't work with any domed pistons.
What about the aftermarket iron heads? Dart or World Products?
Did the valves fail to control the valve train on the speedmaster heads? Up at the top it just falls down while the afr heads stay nice and smooth.
I was interested in reliability as I want a very reliable BBC for my Crownline 24' boat. The bit of extra power just not worth it to me but what about reliabilty? The same??
good heads are more reliable
The expense comes from CNC machining! If you take your low buck heads and have them ported by CNC and you probably be pretty close to HP from high dollar heads! But perhaps the money value of being "CHEAP" isn't so cheap after you do all of the machining!
You should test out a set of skip white performance heads I think there cheaper than the speed masters
I think a lot depends on if it's a street car or quarter mile car and what gears how many times does a street car actually use 5 to 6 thousand rpms richard have you done a video on how much power port matched intake gains on performer rpm manifold
Richard has proved peanut port heads are incredibly good. I'll stick with them. Can't beat the price either.
Yeah, my junkyard mk-iv 454 Combo with factory iron #781 casting oval Port heads unported, stock size 2.06"intake and 1.72" exhaust valves custom grind solid roller cam combo makes more Power from 2500-6000 rpm than my 10 second quarter mile small block combo, it's all over by 6500rpm though. There is more init, but I don't have the money for anymore testing.and I doubt you will do better than that for unported factory oval Port heads and a given amount of money anyway.
There is a lot left in those 781 heads. Bigger valves and widen and flatten the port floor leading and into the short side radius....
For a budget deal, I’d install larger valves and some bowl work on the peanuts. The speedmaster have too many quality horror stories. For similar money you could have similar horsepower without worrying about dropping a valve seat
What about testing a 265 cc Speedmaster head if they make a 265 cc or a 290 cc Speedmaster...just an idea
Need to do a test on the afr enforcer ls heads
The afr is best, no doubt. If you can afford it yea it’s worth it. If not then either the Chinese stuff and add a 150 of nitrous and go. Chances are something better than those ages will come along later anyway.
Richard, in your experience, how large of port volume (on AFR type BBC head!) can you go before it cost a “significant” amount of low end torque? If investing on a quality set of heads is it wise to invest some additional dollars for some “just in case” future power mods??
Believe it was reviously tested: No loss of Tq during test, only potential
don't think about port volume-think about power potential-i like to run the smallest port with the most flow (except on big displacement)
You got more power from the AFR head because of intake port velocity from a stock bore. Test apples to apples. Let’s see what some afr 335s do in comparison to some bravo or assault Chinese 345s
I guessing the AFR heads were fully CNC ported and finished, Vs the Speed masters were as cast. I bet there would be an easy 30 hp in the Speedmasters by simply cleaning up the valve pockets and bowls
Speed heads did not need to be bigger, they needed to be smaller and better
@@richardholdener1727 I get that. I wonder why they made 50 less hp. Has to be a reason. Either a major choke point in the bowls or god awful port configuration. Or both
I wouldnt argue that the afr would still make more power, but it looks like you had a valve control issue with the speedmaster heads. Probably make another 20 or 30 with different springs
Maybe I'm missing something, but I don't see anything indicating a valve float condition until MAYBE 6100rpm. And the torque curve was already well on its way down.
@@AustinRBa the way the power flattens out compared to the afr i believe the spring may possibly starting to loose conrol. Then finally does and you get that crash at the end. The peanut port head most likely kept the oem 3/8 heavey valve and the speedmaster had Chinese springs. I think neither of the prior heads had enough spring for the cam and valvetrain weight. If they did they would be shaped closer to the afr's but not as high just not as high.
big no on 20-30 hp peak power gains from springs
The curve already flattened out, it would of just carried further.
Would like to of seen the smaller oval speedmaster heads tested, kinda a better match to the other 2 heads you are comparing them to. 320cfm is allot of air for that cubes...
Love the test Richard,any chance someday you can test Profiler 320 oval port bbc heads on a 496 combo??
Not a Fair comparison the afr head had small combustion chamber resulting in higher compression. What if you Mill down the Chinese head.?
How about a test with the AFRs
Up against Edelbrock Performer RPM heads
that video is up
Not sure if you covered it... What head gasket do you like to use for Na/ test or boost if different?
mls for boost
Right on
It would have been interesting to see the power numbers with a dyno header that was smaller, more proper sized for that engine!
2:17 Yes smaller is better 😮🎉
Richard, have you compared a factory rectangle port head to a modern aftermarket oval port? Thanks for the videos and all your work!
He has a video testing multiple bbc heads and the oval ports out perform the factory rect ports....
Maybey I missed it? Did you mention what compression each of these heads made? Or the shape of combustion chamber?? I would want to know how much that played a roll in the out put differences?
chamber size was 112 for afr, 121 for speed-chamber design much better on the afr as wll
Why not test everything down to 2000-2500 rpm? A lot of us aren’t making engines to rev to the moon we just want max torque way low for towing or off-roading it’s hard to figure out how to build something use full when everything is how to make 1000 HP at 8000 RPM. I do appreciate this video finally showing some more practical rpm ranges thank you
mostly because no one is ever at wot at 2000 rpm
@@richardholdener1727 makes sense, thank you for the response Richard keep up the good work!
i’ve got a couple different versions GEN 4and a GEN 5 both have peanut port heads my gen4 has an Edelbrock air gap with a 870 demon the gen5 was a TBI a motor as you know we put the same induction as a gen 4 on and made less power and torque i’ve run compression checks on both motors, give or take 4or5 psi cylinder compression on both engines range 200-205. maybe someone can enlighten me where there any differences on a peanut port heads did they change the runner Heights or angles? Have you ran into discrepancies like this Richard?
cams, compression
I've been a firm believer that air speed velocity trumps port volume for horsepower gains anyday. I've seen it far to often with engine combinations I've put together. If there is not enough engine to use the supplied air, it's just wasted. My theory behind that is that the air/fuel mixture just seems to tumble through the port, instead of flowing smoothly, therefore hurting efficiency. What are your thoughts on that @Richard Holdener? Have you done any testing on that? I'd like to check out the video if you have.
see ls3 head testing-you need motor to use head flow
@@richardholdener1727 Thank you for your reply sir
@@georgeashmore9981 I agree with you on velocity. Cam duration plays a role when using smaller ports too. Keep the velocity up for lower rpm, heavy street cars.
Curious if the differences would be closer on a forced induction setup.
imagine the same shape curves but double the hp at 14 psi on both of them. So the brodies were 55 better then they would be roughly 110hp better at 14 lbs boost.
AFR’s*