454 BBC REC PORT VS AFR OVAL-PORT HEAD TEST
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- Опубліковано 26 вер 2024
- DO WE REALLY NEED REC-PORT HEADS TO MAKE BBC POWER? CHECK OUT THIS TEST WHERE WE COMMPARED A SET OF FACTORY, IRON, REC-PORT (088) HEADS TO A SET OF AFR 265, ALUMINUM, OVAL-PORT HEADS. CAN TINY OVAL-PORT HEADS REALLY MAKES AS MUCH OR MORE POWER THAN THE BIG REC-PORT HEADS? SOMETIMES LESS REALLY IS MORE!
500, 600, 800, 1,000+ HP...we just throw these numbers around like nothing these days eh?
Man, if you had a 400 HP street machine, you were something back in the day.
At least they still have to get the power to the ground. A chassis that will only support 200 or 300 horsepower is uncontrollable at 800 or 1000 horsepower.
@camaroguy 66 you know lawrence, I think that only applies to modern automatics. If you can Launch a stick car well, you’re going to put more power down with closer ratios than a similarly equipped 3 or 4 speed auto. All the way through the gen vi camaro.
I believe it was these modern 8 speeds that were the game changers. The ZF8 speed in my scat pack charger was scary good, and i ysed to be able to hassle 6 speed hellcats all the way to 80 to 90 mph before they would blow past me.
Nothing in the above applies to turbo cars though. Automatics are a much better match for turbocharging.
Sticks are still way more fun, and paddles are band-aids.
@@mediumjones,
True that! These high-end 454's are useless to me though! Lol
My TRS drives and transmissions in my boat are good to maybe 450hp! I dont have the many thousands it would take to upgrade outdrives! Hah!
One thing to keep in mind when looking at these numbers from Westech's dyno sessions. They are STD numbers with no accessories. Want to compare them to what a GM OE engine makes on SAE J1349? Deduct about 12% overall. So those 600 hp with a dual plane is more like 530 hp if you want to compare it to what you see on the street from the OEM's. If you tested an LT4 engine like this, i.e undressed it, used STD and raised the running temp to 160 F, it would make 740'ish hp. Not saying it's not a lot, but it is worth keeping in mind how these numbers are to be perceived.
@@AB-80X That's why a Chassis dyno is also a useful tool. Ideally for R&D I think an engine dyno is great for the simplicity of changing parts. I had my 516 on the engine dyno with my headers at least, and I lost some peak but picked up tons of TQ midrange
Excellent test. In the mid 90's I bought a 70 Corvette from a car lot. It had a 454 but they knew nothing about the engine. It turned out to be an LS6 straight out of a 70 Chevelle. After reading an old article by John Lingenfelter that showed a really similar gain using oval ports over rectangular ports I pulled the 088 heads, and factory LS6 aluminum intake, and built a set of 049 oval ports according to Lingenfelter's specs. 2.19/1.88 valves and some mild port work on the short side radius and a port match. This along with an Edelbrock intake and I went from 13.0's in the quarter to 12.30's. I didn't have the money to dyno it. I literally got into shouting matches several times with die hard rectangular port Chevy guys who said I was a fool. They refused to believe that oval ports would make more power. Of course I was only pushing 450 to 480 estimated horsepower. AFR heads I'm sure are much better than some worked over factory heads but I think even the factory heads would have easily supported 600hp.
so true!
we did the same thing on a pair of Merc 454cid boat engines that came stock with the 048 castings but we upgraded the 049's with bigger Intk/Exsr valves and pocket port job and really woke up the engines from stock advertised 330hp to about 475hp @5500rpm.
Port velocity and low lift flow are 2 often overlooked components in a head. Your valve with a .600 lift cam only hits .600 once per event, but will be at .400 lift twice.
True. But there's sometimes other issues with high velocity small ports. You might have high velocity, but you also risk getting turbulence, and that can really hurt the end result. I helped a buddy build a 509 with the 300 cc AFR heads because they read ridiculously high for a 300 cc head. Against advice given from a few of us, he wanted to try it. We contacted AFR to make sure they were on board with our combo. The cam had .680 lift which was well within what Mamo and AFR recommeded, and it was a total disaster. Installed a cam with the same duration but .612 lift and the engine picked up 24 hp average and over 30 ft. average. So many things go into a great cylinder head, and flow numbers are more often than not, pretty useless. Two heads I currently find that really delivers the goods in relation to their port volume is the 24 degree Profiler heads. Absolutely badass 375 and 430 cc heads.
Just look at the .500 flow, huge difference between them.
Variable timing is what it needs the new Chevy LS whatever it's called makes like 300 horsepower at idle with direct port injection, bottom piston oil squirters, better valve angle and there's so many upgrades but the one thing is you can't get into the ECM to make changes yet but somebody will make something to bypass it eventually.and they say you can run one whole more point of compression with the direct port injection. Basically the same horsepower with a lot less boost. Or like most want more boost, more power.
You could make the argument that the valve lingers open at that max lift when it's riding the peak of the cam lobe though. I like the idea of having as much port velocity at low lift because you can get away with less valve spring which is a parasitic loss. The lowest valve spring pressure to maintain control the better.
I had a 509" BBC with that same cam, 10.1 compression, Edelbrock 290 Rovals, Air Gap, 1000 cfm Holley. Great street Engine, it ran 11.80s @115mph with a 3.42 gear at a 4320lbs race weight.
This test makes me proud to be an AFR fan since 1993! But we shouldn't be surprised. Big LS heads make 600-ish hp on 270 cc port volumes. Even cathedral port heads at 235 are wicked. I knew the 088 heads were toast when I saw the AFR's had 20% advantage in mid-lift flow.
A cool follow-up test would be to put the iron heads back on and see how much more cam is needed to match the power of the AFR combination.
Not entirely sure what to think of it. Let's be real, the 088 heads aren't exactly great heads. Pretty easy to expect a significant gain. Would be fun to see this combo with AFR 315 CNC heads. That would be more interesting as they are virtually the same size in both port and combustion chamber.
@@AB-80X I think maybe the AFR oval port heads flow so well because the valve guide doesn't protrude into the port? I wish the video had a good view into the port.
@@andyharman3022
I doubt it. I did a build for a friend and he insisted on using the AFR 305 cc oval heads. Those definitely had the stems in the port and I can't see them doing it much different. Those heads were a disaster btw. We specced the cam lift based on Mamo's recommendations, and the performance was abysmal. Cam had .680 lift. We then tried a cam with the same duration but .610 lift and piced up power all over the curve. Problem with these heads are that they create a ton of turbulence. We put the heads on a flow bench and while they did flow a lot for a 300 cc head, the noise from the air rushing through were ear splitting. Can't say I'm a fan of AFR oval ports.
When looking at this engine here, I wonder how much torque an power this engine would pick up all over the curve by running the 315 heads and a cam with the same duration but 624 lift.
My buddy ended up switching to the 315's and the 680 cam and the numbers were stellar from way down to peak power.
John Lingenfelter set many a record with the early 70's oval smog heads because they flowed very well. Plus oval ports are more efficient than rectangular heads. Also has something to do with surface area friction.
Great comparison. I had a 496 in my 70 Chevelle , 300CC Oval port AFR’s, Edelbrock RPM (non air gap) 248/254 Comp Solid Roller , 10.7:1 CR, 950 Holley Street HP 2” hooker headers - made 706hp @6500 rpm and 643 ft/lbs of torque. Super strong performer. Great heads. Same heads then went on a 572 cube with super victor and 270@. 50 cam and 11.8CR and it produced 807 hp and 739 footies. Now I’m building a 582 With 360cc Mamosport recto heads ..
It seems wild for me how these pushrod engines behave like naturally aspirated 100hp/L is in the rear view mirror for smaller Japanese engines these days but a pushrod V8 will be 500 cubes happy with 500-600hp.
Although I know engines don't scale as well and a bigger engine will always make less HP/L the number always seem pretty unassuming always very tame.
Although 11.8:1 comp is getting into the higher areas
But I daily a Honda with 12.6:1 compression ratio and stock cam no problems honestly it's not the best combo to be high compression with relatively untouched engine but that's how my head/block combo worked out.
I don't think it'll make 150hp at the wheels however.
If your B16A wont make 150 wheel hp, you are doing something wrong. It is harder to make 100 hp/liter as displacement goes up
@@richardholdener1727 not a b16 and not heavily modified it's a sohc with p29 pistons and y8 head twin carb
how did you find the 11.8cr? did you run it on pump gas? did it guzzle fuel even when driving sedate?
@@grantpokarier7412 no problem at all. Doesn’t detonate.
Look at the exhaust flow numbers on the AFR's! That us going to make some huge gains especially with a power adder.
Great for Nitrous / Blower for sure!
I was just getting ready to write pretty much the exact same thing. That's why AFR heads make so much power. Everybody is all giddy about intake numbers but tend to forget about exhaust which I think ends up causing a bottle neck for some heads. AFR or Air Flow Research is a great name for that company because they seem to combine the best of both.
Exhaust port flow was always the weakness of the factory square port heads. The intake ports flowed a ton more than the factory oval intake ports did, but both heads used the same exhaust port. Fine for the oval head, but inadequate on the square port head. Even GM knew it, that's why the old 454 HO crate engines that had the square port heads used a cam with a ton more exhaust duration. I think the cam specs were 211/230 @ .050 because they were trying to help the exhaust keep up with the intake side.
Love the BBC content. Keep up the good work!!
Thank you Sir , I just happen to have a 468 sitting in my garage and was thinking about the best way to improve power levels without touching the bottom end and you just answered all of my questions 😀
Watch the "454 motor home engine" build. With trick flo top end kit. 8.2 compression. Just shows that the power comes from the cam and heads. And more cubes the better obviously
I've been sold on AFR heads for years now. In 2003 Hot Rod tested the 165 cc afr's on a 5.0 and made 405 hp with the stock cam. In 2004 ,Hot Rod tested a set of 195's on a 350 zz4 short block and made 520 hp at 6600 on pump gas. Super Chevy tested the 195 eliminator heads on a 383 in 2006 and made over 540 on pump.
30 years ago I was running modified early oval port heads on my 460 inch daily driver 68 Camaro and beating weekend warriors with big blocks and rect. port heads.In those days nobody ran aluminum heads on the street. They were cost prohibitive.My car was 100 percent street legal and driven to work daily.Driven and raced on treaded tires.
Excellent test Richard. I have been running almost an identical combo for nearly 20 years. 468, 242/248 hydraulic roller but with a different lobe that gives me .612/.638 lift, 10:1 compression. Biggest difference is AFR didn't make the oval port head back then so I run the AFR 305 rectangle ports. I also use the RPM air gap intake and 950hp carb on top of a 1" open spacer. It makes just a pinch over 600hp. Nearly identical to your test. Street driving with some dragstrip mixed in for nearly 2 decades. Very well behaved engine that has no lack of torque down low. 4108 lbs race weight on a 275 radial using a mild 3200 stall 10" converter I've gone 1.57 60 foot and very low 11's at 118 mph. I drive it everywhere. So glad you tested the intake swap. I ended up with the RPM because I didn't want to give up the torque in the range I drive the engine the most. I'd like to see more tests like this. Planning to swap these heads on the new 509 I'm doing with a little more camshaft. Might go single plane at that point. We'll see what the dyno says.
the 305 heads are very good too
AFR heads rule!! Been using them on all makes of engines.
Can’t wait to see some testing with the AFR Enforcer heads. 👍🏻
I’m guessing there would also be a massive weight difference too as an added bonus.
That’s a relatively mild cam for a big block, really good power numbers because of really good heads. Torque peak is only 1.22 lb-ft per cu in and power peak is 1.33 hp/cu in or 1.07 lb-ft. BBCs tend to make lower specific output but make it up with lots of cubes. This engine with either intake would be a blast on the street! More really good info from Richard!
we cammed it for street use
We raced the early oval port heads back in the early to mid 1970's. Some head work and bigger valves, made these run extremely well on the street. I ran the Carter Competition Series 850cfm & 1,000cfm Thermo Quads. On a 180 degree intake manifold. Miss the early days of experimenting around with things...
Cool! Big Bertha thermoquad 👍
Thanx for organizing the videos by motor. The beauty of good low and mid lift numbers is that the valve is at those lifts twice during the intake or exhaust stroke, it’s only at full lift once
That's true, but the valve lingers wide open riding the top of the cam lobe longer than the rest of the lobe profile.
I always loved it when people told me I couldn't get 400 wheel horsepower with vortec heads because you can't get high lift with them. Max flow at high lift is only touched once, a good head is one that flows very well throughout the entire lift range not just peak remember a .500 lift cam will spend more time at .480 than .500 so you want good flow under your peak cam lift
I watched this video several times a week for a long time dreaming about buying these heads. Finally pulled the trigger on them! Fully machined ports set up for my solid roller. Can’t wait to toss them on
That’s a whack of power for such a (relatively) small camshaft!
Awesome test!!
👍🏼
It's the low to mid lift #s that matter. High flow through a small port yields higher torque across the powerband. The AFR head just smokes the factory head throughout the lift range.
Yep! More velocity
Excellent , Love these kind of tests. Keep them coming !
This test I think, more than anything, is a comparison of the technology going into these heads. Those 088 heads are essentially the same rec port head GM has been making since 1965. It's had minor changes to the castings, mostly in the chambers, but is essentially the same head they were making in 1965. Those AFRs are 60 years of advancement in cylinder head design. The exhaust port was always the biggest weakness the factory square port heads had, they need extra exhaust duration on the cam to help them out. That's why the old 454HO crate engine had a 211/230 @ .050 cam in it.
Perfect combination with the AFR and the air gap
I have a customer at work that wants his 1968 Chevy C10 stepside with bbc hoped up a little . Thanks for the recipe.
I’ve been watching your channel off and on, and find it fascinating, and this head test got me thinking about what a guy told me a story about drag racing, so grain of salt, but he told me he blew up his 11:1 bottom end, so he took his cam and heads and put them on a stock 8.5:1 short block and his time slips dropped about .4 of a second. I thought compression had a lot more effect, but airflow is king is seems. Keep up the good work👍
each point is worth 3-4% in power
Thank you for creating the BBC playlist. Great content as usual. I still think you and @dynobrule should create a BBC specific channel
Thanks Richard
Great results! Keep testing, I'll keep watching.
Thanks for all or your work Richard!
excellent video! i run older oval big brodies raised runners on a 510 short deck in a 1971 stringray on street. torque and throttle response is like fuel injection! insane torque. even street race bikes have hard time hanging in. OVALS rule!! just had a new custom gring solid roller cam fabbed by isky. now motor dynos over 800 hp. insanity!!! best thing is i hide it all under factory big block hood with old 1080 barry grant carb. sleeper that destroys! dr thrash
Hell Yeah Rich back to the GM stuff is where things get Fun.. plus a big Block man it never gets old💪🏾💪🏾💪🏾💪🏻💪🏻💪🏻👀😎
Nice info!!
That's the case when bigger is not always better.
Thanks
Oooo. Love the Playlist idea.
That had to be a ton of work. Thank you 👍.
Awesome comparison and heads joined it very much
All the rec port guys be like "but, but, but, but." Lol. Those mid lift numbers make me wanna shrink down and put a radar gun on those air molecules. Air velocity has gotta be just crazy fast. Exhaust flow numbers nearly matching the rec port intake flow numbers? Holy wow man. 80hp peak gain with solid gains everywhere? Wow. Just wow. Do they make a Pontiac version? Asking for a friend. Lol
I’ve been saving to get those AFR’s!!!
You have a ton a amazing info on how to build for every power level on every engine.. Id like to see some " how to build for ever budget" Where you do a 3K, 5K, 10K, +++ build to show the kind of power you can get on each budget.
Several years ago I help a fellow when I worked for GM as a line mechanic on his 68 Camaro that had a aluminum 427 chev power glide ect in his car. He told me back then that the oval port head that were ported by folks that knew how to make them work were a pretty impressive head. He had been talking to some guys that built motors in the Dallas area . There still there I believe . That was a long time ago but I never forgot what I was told about those head .
We made 600hp / 600ft-lbs on M2 race systems engine dyno years ago with hand ported oval heads on a 454. It had a custom hyd roller cam from Anthony Disomma who actually rebuilt the motor. Cp was 10.8:1 and it was topped off with a single plane victory jr intake. Very simple build with mostly factory parts.
Love the channel playlist breakouts...thank you.
From my math it went from exactly 10.00:1 to 10.64:1 which is a decent compression bump but since you were going to aluminum heads that alone won’t really do much, the 50 year newer technology of the AFR Heads is what gained all the power !!!!
Love the playlist
569 foot pounds on 468 cubes is 1.21 foot pounds per cubic inch. Ideal is 1.3 which means there's power to be had!
It wants a different intake. Ideally, a longer runner will do it, but a tunnel ram is worth a shot.
This is so true man.....but i knew a ol wildman back years ago that ran and ol 66 chevelle 427 square port/solid cam.4-speed 4;10 with factory parts through out that ran 11;60,s give or take all day long....ol timer.....when someone would build a magizine built engine and wanted to know how it ran....you ran him....low cost....those heads on here cost more than his car and he still has it to this day.....he twist that ol big block up there in the rpm,s.....money has took over on the true hot rodders.
It’s a bummer the 3 thumbs down guys must have had a bad day today !
Chris Those are Ford guys.
@@davidcollis4758 Or LS guys.
Some see BBC and think it’s porn... so
pretty sure any thumbs down on this video comes from him saying ''Rec-Port'' head.....cringeworthy.....
Great job on the videos Richard. AFR kicked ass but they are quite expensive. I am totally impressed by the power output with such a small cam, kudos to comp cams. I wonder what would have happened if the cam was swapped for one with lift of .600 to .650 with a 244 to 248 duration?
Round '95ish was following a Pontiac head porting series
Limited volume max flow techniques for super stock
No aftermarket heads
There were few then any how.
Rich I would like to see RA 4 722 heads or 71 455 HO and the 6X heads from mid 70s
Look at the stock port shapes
Cool stuff
I just bought my first set of AFR heads. 190 vortec for my pu
That was a freaking awesome video
Wonderful test love it
Sometime I'm going to put my new 540 engine together. Around 9.1 - 10.5 to 1 compression, iron oval Port heads, nitrous hellfire top rings, 4150 carb, hydraulic roller with around 230 at .050" 2,000 stall. My big shot adjustable plate and with my adjustable top shot nitrous in the air cleaner for 2 kits with a Max of about 575 extra ponies of nitrous fun for the street and some track. It may die with that much nitrous but you got to try. I've had great luck with nitrous over the years.
The title had me wondering why the British Broadcasting Company would be worried about 454's.
Nice seeing Richards subscriber numbers climbing.
thnx to everyone for that
All AFR heads seem to make more power than the others
CFMx2@ (.78 X peak cam lift) explains what the engine should make on both combos. This formula almost tracks every time on my bench if I test with an intake manifold on the head.
airflow is only 1 part
don't ignore the added 80 cfm on the exhaust! Lingenfelter always said the intake makes torque, the exhaust makes HP. You could also have gone with a 1150 cfm carb on the dual plane and closed the gap with the single plane.
I went with a mild setup on this engine so I would blow up my trans while towing. Got to building vthem for extra building room later on 🤘😁🤘
Velocity! I like building peanut port heads for street/strip. I always have the last laugh! 🚦 😊
The most power I could make with a 454 and factory rec port heads was 706 ,and I worked on those heads for ever
Port and polish that iron head and then compair the 2.
Ive been running Edelbrock Perf. RPM Oval port heads on BBC's since the 90's. 290 heads. They work really well.
Agreed. And I like that Edelbrock makes a 100cc chamber version. It gave me 10.15:1 compression with tiny 8cc domes. Good stuff. They don't flow like AFRs but still make good power for a street motor.
those are good for junkyard upgrades as well
I was expecting 40-50hp. 80hp is insane!
I have a pumpgas , oval port, hydraulic roller 462 that makes 570hp. Flat torque curve. Hand ported heads. 10.4/1
I’d love to see a video with a 396 wit afr265
Big block Chevy have a bit of a handicap in port design. Cylinders 2 6 3 and 7 run leaner do to the fact that the port is angled into cylinder wall where 1 5 4. And 8 have more of a swirl into cylinder. I wonder how cid symmetrical port heads would stack up to any other head? big block pro stockers ran Pontiac symmetrical heads for this reason. There is a way to offset the leaner cylinders by running one step cooler plug in those cylinders. It’s all pretty much bench racing theory but maybe you can run some Dyno sessions on this with some exhaust temp readings? Thank you Richard for all your research on big blocks
You know what I'd like to see?... I'd like to see a comparison of stock iron heads, like 781's, 840's, 360's, 292's, 391's, etc.!! No port work, just a good valve job and let 'em rip!!!
Aluminum heads can handle more compression. And need more at least a full point to compare to iron because of fast heat dissipation. AFR are truly one of the best out there.
i will keep my high flow oval port heads for the street square port for drag racing
I would love to see what the power curve does at the lower speeds with a 218 or 224 @.050 cam.
Me too.....that’s the size of my Straub/Clay Smith cam!
Yes, a sensible street cam. agreed
The small port oval, 110cc heads cost a lot more. GM,DART,AFR etc wonder why?
John Lingenfelter made 630hp out of a set of ported peanut ports. Can't remember the whole build but he shut a lot of haters up real fast.
530?
@@richardholdener1727 I got a magazine somehwere that has the article. You're probably right with the 530hp mark.
Been looking at the 265 heads but been contemplating the cheaper afr 320 enforcer heads (rec ports) that are roughly $800.00 cheaper.
Our short block is similar except it has a small Howard’s solid roller with .600 lift and 237/243 duration @.050.
Haven’t really seen any back to back tests with the Enforcers.
Would love to see a shootout between the AFR 265's and the Brodix 270 Race-Rite heads. Both are available with CNC'd chambers. I'd give the AFR's a slight advantage because of their raised exhausts. But, I bet it would be a interesting battle.
see the oval-port head test video
AFR heads are a no brainer, but they are not necessary to achieve those power numbers.
Don't leave us hanging, please clue is in on what is necessary.
As soon as I saw the low lift cam, I knew it was less of a contest than a clinic.
Same oval port intake?
clinic?
Is he laughing at my 840"s and 990"s ?
Oval port intake on rec port heads works nice in an 8th mile car
Throw in some 206 factory ovals with 2.190vlv
Yeah. They have closed chamber and large oval port
Thank you for your videos great content
That's a great idea, Richard ! Throw all the BBC stuff in one place so it can be found quicker.
Those little AFR's are THE SHIT. Science ! 👌😎👍
9👍's up thanks again for taking us all along with you for the great show
Awesome vid Richard !! Man, i wish AFR had an offering for Big Block Mopars.. 😕
I have something close to that combo w/ the AFR heads, but in talking with AFR and some cam guys they say those heads prefer a single duration cam. Any chance in doing a spilt vs single duration cam test on that motor?
What combo are you running and what kind of power did it make? I have a split duration cam with AFR 335's and it turned out wicked.
I have a pair of 088 heads on my 468 in my 57 Bel Air. I'm going to replace them with a pair of AFR 265. It's strictly a street car and I seldom twist it above 5,000 rpm.
Great video.
Have you ever done any test with 820 factory heads
Great video
I wonder how the merlin 269cc flow & make power ? Thanks Richard Holdener
How about doing the AFR 290 heads to get past 600 hp and then 100 shot in a 20 foot ski boat Stern drive.
Could've summed it up in five minutes!
Question...
Was the power/torque gain mostly from the exhaust side?
I ask because the intake side showed a good up it air flow
But the exhaust side was definitely a bigger gain.
Hi Rich--i am 65 and remember the oval VS rect. port debates back in the day. In the mid 70's i built a 67 Yenko clone Camaro and my buddy found a 427/425 with a spun rod bearing at his mach. shop so it had the rect. port heads, solid cam, 11:0 pistons, etc. I think the actual factory rated increase VS the oval heads was mainly from the bigger valves and not primarily from the bigger/rect. port heads? Did you ever see the PERFORMANCE engine rebuilding series on how he built a 620 hp BBC with cast oval heads ported by him?. He explains which cores have the best chance of good flow and oddly enough its the later versions with the bigger chambers, he also shows what 99.9 % of the people didnt know back then was casting shift and the good port and bad port scenario. Do you think its possible that the casting process improved over the years from say 68-77 remembering that in mid 70's the 454 wasnt known as a performance engine so i doubt GM cared about flow but might have improved on casting process? I am sure that an AFR AL head isnt affected with such things as core shift, etc. like heads from say 1969. Yes your head swap yielded 80 hp and more torgue and considering they were a bolt on thats very respectable providing someone has the $$$ for the heads, but like anything more power = more $$$$$, great comparison BTW
Richard, you are the bbc guru!
thnx but hardly
@@richardholdener1727 don't sell yourself short. Your work is much appreciated and adds much to the book of knowledge on BBC's.
I love when you give me tips on the Gen 5 peanut ports because I just acquired one for my 1960 El Camino.
What happened at .100 lift with AFR intake flow? It was lower than the rectangle iron head.
From what I have found you have to cc any bbc factory head, I used a set of mid seventies truck oval ports, flat milled .020 and a set of L88 pistons thinking they would be around 128 cc heads. Had a terrible pinging problem, tried everything, finally coed the heads and they were 111 cc so was at 12.75 to 1.
theres no "thinking" there is only "cc'ing"
Here's a point a dynoed 700 horsepower blown 454 head comparison test. with an iron oval Port head in car craft a few years ago beat out the square port iron heads. The myth is the factory square Port head will be out the factory big oval port. That's not true the iron oval Port head beat the square port with more horsepower and torque across the board. And the iron oval Port head will definitely make more horsepower and torque in a smaller milder big block Chevy. Going too big in a cylinder head, carb, intake, headers will usually kill alot of torque to usually make a little more horsepower. Horsepower looks good at car shows and on paper, torque is what wins races at the drag strip.
What are your thoughts on AFR 305 heads on a 565ci big chevy with a bds 10-71 on top...??
that exhaust flow tho!
yes