One of the main reasons I watch your videos is your brutal honesty even when at your own expense. Not many businesses would have even shown this video.
Information is never a fail! Even if that information is what you believed to be correct, now you know. David Visard on his channel gave you recognition on your SBC work. That's a badge not many get! I appreciate the honest results you provide, even when disappointing. That alone is rare and is what brings me to your channel. Keep up the good work.
I've been tossing up to go CNC or hand ported problem I have is who ported the head that was digitised, not all head porters are created equal, in my racing days my engine builder would spend hours on the flow bench with his piece of string and I'm glad he did as no one could match our numbers. today every tom dick or Harry offer CNC port job head so who do you pick atm im leaning towards hand as I know ill get a killer set of heads, why I'm even concidering CNC is price and my engine is big Turbo 427 LS where intake isn't as important its the exhaust is were its at with boost
Hey Eric, Tim here, yes, i believe cam is the culprit, but for ALOT of the folks buying that head, wud have similar specs, or less, so, your data is VERY usefull, for MANY combo's, and the heads wud be useful, in MANY scenarios......maybe not go after the best # persay, but the overall usefulness of the ported head, i think is SUBSTANTIAL!!!...........my Stock Eliminator buddy, PREACHES combination, combination, combination!!!....so with ur fairly aggressive solid roller, at 260/270, shud cover MANY other builders, and the head wud work well, dont beat urself up so much, ur WHOLE test here is just FANTASTIC, and i dont really care cuz i'm a Poncho guy, my point is, ur toil has PROVED to be VERY usefull for MANY combo's!!.....this was one of my fav vids!!!.....you are a very talented young man.....i'm a bit older than u (57)......i cant wait for the next vid!!!....JUST LOVE IT!!......btw, keep braggin on Bishop all u want, i have no kids, so i enjoy ALL ur braggings on his swim meets!!!....PEACE to you brother!!
Hi Eric, I have a 71 C10 with factory 402 block still in it. When I bought it 25 years ago prev owner had bored it .030. Since then, I have been through it again and freshened it a few years ago. Now has hyd rollers with a good low end street cam, edelbrock perf rpm, ceramic headers, billet dist, ultra avenger carb, and is a very nice gentlemens hot rod truck. Cast heads were ported and polished by a good machinist and it made 425h / 472lb ft on the dyno, all below 5200rpm. It is very strong from about 1800 and is a stop light to stop light stunner. Obviously it's a small cid big block. Dart only makes a cast 275cc oval ports for it (19900172H), no cnc version on that small of a head. WHAT SAY YOU? I'm going to freshen it again and wanted the absolute best alum heads I can put on it. Obviosly Dart makes good heads but do you think a CNC on that small a cid would make much more of a difference? I want to shed the cast weight and make as much torque as this little bottom end can make. THANK YOU FOR ALL YOUR GREAT INFO!
Great video! Looks to me like you’re testing a system and need to make everything work together. If you increase the wrong part (whatever that might be), you don’t see the change you wanted. Looking forward to more test results. Thanks, Eric! OBTW, how about some more tunnel ram tests?
Hi Eric, Great content as always. Question for ya, if you had 2 sets of identical heads with the only difference being one is iron and one is aluminum, would the iron set be preferred on a lower compression NA engine of around 9.0:1, or does the weight savings neglect any heat retention benefits.?
I would think having each chamber the same CC for example, and the ports far more equal overall would perhaps allow using more spark advance with less risk of detonation ? Quantifying a benefit like that might be more difficult than just "HP and Torque". Maybe even more of a benefit in racing classes where at times they struggle with less than optimum coolant temperatures at times.
This is an honest question: could you compare your 406 you have now with David Vizard 383 that made 621hp? 23 CI less but almost the same power. I don't wanna start wars, I'm just someone who listen to many people. Many thanks, great video, good day.👍
Well mine is a real dyno sheet and his is a spread sheet. It would not have made that power on the Dyno I use. I could go to another not 45minutes from me and make 700hp. So you can’t compare dynos like that especially with someone selling books based on high numbers.
Seems to me like vizard, great as he is, builds one off motors where he reworks every little details that you would never do in a typical build like reshaping counterwights or radius the bore bottoms. Whereas eric's motor is a claimed 400 shortblock that he threw different heads/intakes on to get hard data. Isnt apples to apples And like eric said we dont get actual dyno sheets in Vizard's videos
I’ve noticed that you are pretty critical of David Vizard’s work. He is complimentary of your work. I think you should collaborate with him and do a dyno shootout.
I’m more critical of dv fans. I don’t enjoy being told I don’t know what I’m doing because dv did so and so. But they have never tested what dv said to see if it really is true. Meanwhile I have.
I don't see it as a fail. Disappointing, OK. Still it's valuable information. I think you're right about the cam. 600+ HP on pump gas is still impressive.
You are exactly right on the bigger heads on a 434. Someone else is building 427 434 with smaller hydraulic roller trick flow 230 and r manifold making almost 600 on a honest dyno.
I'm glad you make these videos because it helps me a lot in the direction I want to go with my build. So I'm also glad a watched until the end. So in your opinion should I go with a lift in the 700 range as opposed to the 680 lift on your fully ported project x 215s on my 421 or wait to see what the results are of the new heads your working on? I'm waiting on results before I purchase heads from you.
@@WeingartnerRacing that's exactly what my engine builder said, he'd like to see me in the 700 lift range on the 421. He was hoping for 725 to 750 hp. But I'm not so sure a 335cc head would support that? I'll wait for your dyno on the new heads. Even if I made 680 hp I'd be happy with that. Everything is all about combination. Keep the videos coming love the content
For naturally aspirated, pump gas, street bound engines, that don't see over 6500rpms, cnc'd heads are not cost effective. I'm doing a 383cid first gen sbc this winter, and the Edlebrock E-215's with cnc'd intake mouths for decent gasket matching is gonna be the head for me on this build. They're basically the E-200's with some additional cnc work in a few areas. Very cost effective, given the minimal difference in price from as cast heads. The only other heads I've considered are the Trick Flow offerings in that 200'ish cc range. If your after the last few horsepower in a limited displacement bracket racing class, then maybe fully cnc'd heads get you the win. Otherwise save your money for more machine work.
No. The members at the time were sent these numbers as it was happening. Usually when a person joins I just give them the last session numbers and all moving forward.
Being the torque and the torque peak is exactly the same regardless of intakes says everything, it being 1.35~ tq pr. ci on pump it needs more cam so it can be moved way up. Although did you test it with a tunnelram? If so it would barely make much difference I assume.
Eric, great video!!!...thanks for your brutal honesty!!...it's great to hear nowadays...I have a question about the Project X heads....you said you milled them from 70cc down to 64cc...that's a full 6cc...I have both emailed Promaxx and visited their Rainbow City Alabama location to inquire about the 185cc SB Ford version Project X heads and both times was informed these heads could only be cut from 58cc down to 56cc...that's only .012"....twelve thousandths of an inch??...Do you have any knowledge as to whether the decks on the Ford version are really that thin???...I'm thinking of ordering a set from you and having you critique them for a video, but I don't want to find out too late that I can't get the compression I need with my current short block...I greatly appreciate any knowledge, comments, or thoughts you might have....Thanks again for another great video and please keep up the great work!!
Yes, I've seen that before...but, this is supposed to be a performance head and if I can't mill for compression it's only going to be 9.7 to 1 as is. This will kill torque and obviously won't make power...Do you have any other suggestions that won't break the bank?...maybe angle milling, or a different head?...Thanks much... @@WeingartnerRacing
I think i would go with a little more than 4° of duration on the intake side. Maybe 6-8° on the intake site and a couple four ° on the exhaust, but I've never competed in engine masters either. Either way I'm with you, you've ran out of cam.still hard to believe that little Victor jr does as well as it does.
Have a sbc 350. Edelbrock 1551 mini blower overdriven with a 2.9 inch pulley instead of a 3.6 inch to make 7spi. Edelbrock estreet heads that i cleaned up following your videos. My question is would going to a larger head like the 235 really help in power. The air going in is under pressure. I would imagine with even better flowing heads would just make less boost and the same power??
Cam is a Daughtry custom blower cam at 228 234 at 50 and 535 lift on a 114lsa. Idles relatively smooth at 950rpm with the 10.5lb flywheel and mini 6inch harmonic. Scat forged rotating assembly . 9.5:1 . 850dp blower carb. Water meth injection. 29deg at full boost timing with the msd 6btm. All in an old c3 vette. I pull New mustang gts on the street and on hwy runs. But always need. More. Nitrous or better heads?
@@soldierbynamefrom what I know cams with lower LSA like 107-109 make best power. Just my two cents I could be wrong yet seems like common sense but more flow in and out is always better right..especially with boost.
Do you flow manifolds? Is there a rule that says the manifold runner needs to flow (x) more than the cylinder head runner to make more power? More by volume, same legnth runner.
You would hope it's the camshaft holding it back but also .685 lift is that already kinda big or a 400 they usually want more just curious. Like .720 .730 or whatever. .264 duration I am with you on that for sure I wonder how much 4 points of duration on intake would increase power band. And I kinda wonder to how are people run like 8000rpm with these 400s if your peak is only 6700 just more cam yeah I can't wait for that test
Imagine what they’d do on a boosted engine. Seems like hp gets exaggerated once it’s boosted. If it’s better na, then it seems to be even better under boost.
i dont see a fail, you showed that the total combination is important. a good head, and good cam wont get it with a bad intake. mix and match all 3 and it will be the same, it just shows that everything has to work together to be optimized. bets head in the world aint crap if you have a mediocre intake, and a peanut cam....
14:12 Why does it look as though you removed all the data below 4700rpm (2/3 of the rev range) for the std heads because it showed such bad losses for the CNC heads...? Saying you didnt do it is suspiciously convenient that it ends exactly at the point of crossing over..!!
I think you have it reversed. I tested the Cnc heads at 4000rpm or so. If I remember the first test that I did were a shorter rpm band to test. Latter I tested a broader range because people complained.
@@WeingartnerRacing The black line is the std head which starts at 4700rpm where it crosses the red line of the CNC head which starts at 4000rpm. Both lines should have started at around 2000rpm since below 4700rpm is where a street motor will spend most of its life. It is clear from your flowbench testing the CNC head only flows about 1% more at highest flow levels. Which related to 12hp on the dyno. At bottom end flow the std head is about 12-14% MORE! How many hp LOSS did that relate to? We dont know because you didnt show that. Therefore I would suspect the losses below 4700rpm are a lot bigger than the small gains above. Meaning this CNC porting was not worth while for a none race engine. Which is the opposite of your videos conclusion...that would seem disingenuous to your viewers.
You clearly didn’t watch the video all the way or cherry picked. If you had you would’ve seen the comparison at 4000rpm vs non Cnc ported head and Cnc ported heads with the Vic jr. The Cnc ported heads made more power at 4000 than non. Not only that the difference was growing at lower rpm meaning it was looking if I pulled the dyno lower the difference would have been greater in favor of the Cnc ported heads. This same trend was also seen on the 2970 and the 2892. So your conclusion is false. Nobody would claim this engine to be a street motor. Also 2000rpm dyno pull is almost pointless because no street car is under full load and wot at 2000rpm. If you tell me you are then you need to down shift. You are confusing part throttle driving which I don’t test.
Авто/Мото
One of the main reasons I watch your videos is your brutal honesty even when at your own expense. Not many businesses would have even shown this video.
It's crazy how people think a chamber and ports have to look pretty to move air but people do.
Information is never a fail! Even if that information is what you believed to be correct, now you know. David Visard on his channel gave you recognition on your SBC work. That's a badge not many get!
I appreciate the honest results you provide, even when disappointing. That alone is rare and is what brings me to your channel. Keep up the good work.
That’s what makes your channel awesome straightforward honest info.
👍 I greatly appreciate your style and honesty in your videos.
I've been tossing up to go CNC or hand ported problem I have is who ported the head that was digitised, not all head porters are created equal, in my racing days my engine builder would spend hours on the flow bench with his piece of string and I'm glad he did as no one could match our numbers. today every tom dick or Harry offer CNC port job head so who do you pick atm im leaning towards hand as I know ill get a killer set of heads, why I'm even concidering CNC is price and my engine is big Turbo 427 LS where intake isn't as important its the exhaust is were its at with boost
Hey Eric,
Tim here, yes, i believe cam is the culprit, but for ALOT of the folks buying that head, wud have similar specs, or less, so, your data is VERY usefull, for MANY combo's, and the heads wud be useful, in MANY scenarios......maybe not go after the best # persay, but the overall usefulness of the ported head, i think is SUBSTANTIAL!!!...........my Stock Eliminator buddy, PREACHES combination, combination, combination!!!....so with ur fairly aggressive solid roller, at 260/270, shud cover MANY other builders, and the head wud work well, dont beat urself up so much, ur WHOLE test here is just FANTASTIC, and i dont really care cuz i'm a Poncho guy, my point is, ur toil has PROVED to be VERY usefull for MANY combo's!!.....this was one of my fav vids!!!.....you are a very talented young man.....i'm a bit older than u (57)......i cant wait for the next vid!!!....JUST LOVE IT!!......btw, keep braggin on Bishop all u want, i have no kids, so i enjoy ALL ur braggings on his swim meets!!!....PEACE to you brother!!
Hi Eric, I have a 71 C10 with factory 402 block still in it. When I bought it 25 years ago prev owner had bored it .030. Since then, I have been through it again and freshened it a few years ago. Now has hyd rollers with a good low end street cam, edelbrock perf rpm, ceramic headers, billet dist, ultra avenger carb, and is a very nice gentlemens hot rod truck. Cast heads were ported and polished by a good machinist and it made 425h / 472lb ft on the dyno, all below 5200rpm. It is very strong from about 1800 and is a stop light to stop light stunner. Obviously it's a small cid big block. Dart only makes a cast 275cc oval ports for it (19900172H), no cnc version on that small of a head. WHAT SAY YOU? I'm going to freshen it again and wanted the absolute best alum heads I can put on it. Obviosly Dart makes good heads but do you think a CNC on that small a cid would make much more of a difference? I want to shed the cast weight and make as much torque as this little bottom end can make. THANK YOU FOR ALL YOUR GREAT INFO!
Great video! Looks to me like you’re testing a system and need to make everything work together. If you increase the wrong part (whatever that might be), you don’t see the change you wanted. Looking forward to more test results. Thanks, Eric! OBTW, how about some more tunnel ram tests?
I should at the beginning of next year.
Eric I appreciate your candor. I also enjoy your videos and I do agree with you in regards to the camshaft.
Thanks
Thanks for the great video, you are a wealth of knowledge.
Great video and great results!
Thanks for sharing, all the best to you and your loved ones
Hi Eric, Great content as always. Question for ya, if you had 2 sets of identical heads with the only difference being one is iron and one is aluminum, would the iron set be preferred on a lower compression NA engine of around 9.0:1, or does the weight savings neglect any heat retention benefits.?
Keep the awesome videos and hard work coming Eric !!!
Thanks! Will do!
Charles Servedio does. He's porting swirl port heads right now.
I would think having each chamber the same CC for example, and the ports far more equal overall would perhaps allow using more spark advance with less risk of detonation ? Quantifying a benefit like that might be more difficult than just "HP and Torque". Maybe even more of a benefit in racing classes where at times they struggle with less than optimum coolant temperatures at times.
This is an honest question: could you compare your 406 you have now with David Vizard 383 that made 621hp? 23 CI less but almost the same power. I don't wanna start wars, I'm just someone who listen to many people. Many thanks, great video, good day.👍
Sure he could put it on the dyno I use and see what it really makes.
@@WeingartnerRacing I was refering to this: ruclips.net/video/f66F64vSP4g/видео.html
Well mine is a real dyno sheet and his is a spread sheet. It would not have made that power on the Dyno I use. I could go to another not 45minutes from me and make 700hp. So you can’t compare dynos like that especially with someone selling books based on high numbers.
@@WeingartnerRacing Thanks for your answer.
Seems to me like vizard, great as he is, builds one off motors where he reworks every little details that you would never do in a typical build like reshaping counterwights or radius the bore bottoms. Whereas eric's motor is a claimed 400 shortblock that he threw different heads/intakes on to get hard data.
Isnt apples to apples
And like eric said we dont get actual dyno sheets in Vizard's videos
I’ve noticed that you are pretty critical of David Vizard’s work. He is complimentary of your work. I think you should collaborate with him and do a dyno shootout.
I’m more critical of dv fans. I don’t enjoy being told I don’t know what I’m doing because dv did so and so. But they have never tested what dv said to see if it really is true. Meanwhile I have.
I don't see it as a fail. Disappointing, OK. Still it's valuable information. I think you're right about the cam. 600+ HP on pump gas is still impressive.
Good video Eric.
Thanks for sharing. 👍
You bet
I have learned so much from your videos. Thanks
Glad to hear it!
The Project X CNC 235 and the Trick Flow Super 23 230 cnc heads are very similar. very nice!
Flow curves the trick flow is better lower and I’m better up top.
You are exactly right on the bigger heads on a 434. Someone else is building 427 434 with smaller hydraulic roller trick flow 230 and r manifold making almost 600 on a honest dyno.
Old man has some good pieces.
I'm glad you make these videos because it helps me a lot in the direction I want to go with my build. So I'm also glad a watched until the end. So in your opinion should I go with a lift in the 700 range as opposed to the 680 lift on your fully ported project x 215s on my 421 or wait to see what the results are of the new heads your working on? I'm waiting on results before I purchase heads from you.
Above .700 is preferable
@@WeingartnerRacing that's exactly what my engine builder said, he'd like to see me in the 700 lift range on the 421. He was hoping for 725 to 750 hp. But I'm not so sure a 335cc head would support that? I'll wait for your dyno on the new heads. Even if I made 680 hp I'd be happy with that. Everything is all about combination. Keep the videos coming love the content
@@WeingartnerRacing either way the engine should perform awesome in my 78 chevy nova. But man is this car hard to find parts for!
For naturally aspirated, pump gas, street bound engines, that don't see over 6500rpms, cnc'd heads are not cost effective. I'm doing a 383cid first gen sbc this winter, and the Edlebrock E-215's with cnc'd intake mouths for decent gasket matching is gonna be the head for me on this build. They're basically the E-200's with some additional cnc work in a few areas. Very cost effective, given the minimal difference in price from as cast heads. The only other heads I've considered are the Trick Flow offerings in that 200'ish cc range. If your after the last few horsepower in a limited displacement bracket racing class, then maybe fully cnc'd heads get you the win. Otherwise save your money for more machine work.
LoL
You're the epitome of what he was talking about at 13:44
Thanks for your contribution 🤣
Awesome video, as always.
Thanks again!
Glutton for over workin
Great video
Love the long videos
Thanks for watching
This is a great video.
Also, if you're a channel member, should we be getting these results? Or was the deal a while back only for a little while?
No. The members at the time were sent these numbers as it was happening. Usually when a person joins I just give them the last session numbers and all moving forward.
Being the torque and the torque peak is exactly the same regardless of intakes says everything, it being 1.35~ tq pr. ci on pump it needs more cam so it can be moved way up.
Although did you test it with a tunnelram? If so it would barely make much difference I assume.
Exciting video thnx Eric
Glad you enjoyed it
Great content
I think it is fair to u are a walking wealth of knowledge in the 23 deg sbc head so dont feel bad about talking so much thanks Rocket fromMO
Eric, great video!!!...thanks for your brutal honesty!!...it's great to hear nowadays...I have a question about the Project X heads....you said you milled them from 70cc down to 64cc...that's a full 6cc...I have both emailed Promaxx and visited their Rainbow City Alabama location to inquire about the 185cc SB Ford version Project X heads and both times was informed these heads could only be cut from 58cc down to 56cc...that's only .012"....twelve thousandths of an inch??...Do you have any knowledge as to whether the decks on the Ford version are really that thin???...I'm thinking of ordering a set from you and having you critique them for a video, but I don't want to find out too late that I can't get the compression I need with my current short block...I greatly appreciate any knowledge, comments, or thoughts you might have....Thanks again for another great video and please keep up the great work!!
That might start to cut the Intake seat. 0.012 is barely a cleanup cut.
It depends on the head. Some heads you barely mill them and you are into the seat.
Yes, I've seen that before...but, this is supposed to be a performance head and if I can't mill for compression it's only going to be 9.7 to 1 as is. This will kill torque and obviously won't make power...Do you have any other suggestions that won't break the bank?...maybe angle milling, or a different head?...Thanks much... @@WeingartnerRacing
Thank you for your knowledge and video's USA 🇺🇸 USA 🇺🇸
Thanks for watching!
I think i would go with a little more than 4° of duration on the intake side. Maybe 6-8° on the intake site and a couple four ° on the exhaust, but I've never competed in engine masters either. Either way I'm with you, you've ran out of cam.still hard to believe that little Victor jr does as well as it does.
It is shocking
Have a sbc 350. Edelbrock 1551 mini blower overdriven with a 2.9 inch pulley instead of a 3.6 inch to make 7spi. Edelbrock estreet heads that i cleaned up following your videos. My question is would going to a larger head like the 235 really help in power. The air going in is under pressure. I would imagine with even better flowing heads would just make less boost and the same power??
Cam is a Daughtry custom blower cam at 228 234 at 50 and 535 lift on a 114lsa. Idles relatively smooth at 950rpm with the 10.5lb flywheel and mini 6inch harmonic. Scat forged rotating assembly . 9.5:1 .
850dp blower carb. Water meth injection. 29deg at full boost timing with the msd 6btm. All in an old c3 vette. I pull New mustang gts on the street and on hwy runs. But always need. More. Nitrous or better heads?
@@soldierbynamefrom what I know cams with lower LSA like 107-109 make best power. Just my two cents I could be wrong yet seems like common sense but more flow in and out is always better right..especially with boost.
Like Richard Gere in officer and a gentleman
Do you flow manifolds? Is there a rule that says the manifold runner needs to flow (x) more than the cylinder head runner to make more power? More by volume, same legnth runner.
For a solid year I flowed manifolds alone. It lied to me. Several flowed more and made less power.
I never asked but did you also do the cnc Promax heads for the sbf?
Nope
You would hope it's the camshaft holding it back but also .685 lift is that already kinda big or a 400 they usually want more just curious. Like .720 .730 or whatever. .264 duration I am with you on that for sure I wonder how much 4 points of duration on intake would increase power band. And I kinda wonder to how are people run like 8000rpm with these 400s if your peak is only 6700 just more cam yeah I can't wait for that test
It’s in the cam. If you over duration it the peaks will come up but the low rpm will be soft.
How much for a set of 215 X sbc heads ? I have a 383 with a TBS 192 blower on it with 200 cc China heads on it now.
It’s best to email me that.
Imagine what they’d do on a boosted engine. Seems like hp gets exaggerated once it’s boosted. If it’s better na, then it seems to be even better under boost.
Boosted engines respond more to better exhaust flow.
What's price difference between t227 afr and the CNC pro Max
Depends on which version of Afr227
Is this the promax heads?
Did you even watch the video?? Do you have eyes and ears?? SMH
I don't know how a Mopar Magnum head outflows an LA head; the pushrod pinch takes up half the port opening. Could anyone shed some light on this?
That's a big cam needed
Yep
Check out ersons 264/272 @ 050 on a 108 . Nice work and great info !
i dont see a fail, you showed that the total combination is important. a good head, and good cam wont get it with a bad intake. mix and match all 3 and it will be the same, it just shows that everything has to work together to be optimized. bets head in the world aint crap if you have a mediocre intake, and a peanut cam....
Go 4 Deg. on the intake and close your LSA down to 106 Deg. Spinning to 7500 will be easy.
Perfect after you fix them....😂
14:12 Why does it look as though you removed all the data below 4700rpm (2/3 of the rev range) for the std heads because it showed such bad losses for the CNC heads...? Saying you didnt do it is suspiciously convenient that it ends exactly at the point of crossing over..!!
I think you have it reversed. I tested the Cnc heads at 4000rpm or so. If I remember the first test that I did were a shorter rpm band to test. Latter I tested a broader range because people complained.
@@WeingartnerRacing The black line is the std head which starts at 4700rpm where it crosses the red line of the CNC head which starts at 4000rpm. Both lines should have started at around 2000rpm since below 4700rpm is where a street motor will spend most of its life.
It is clear from your flowbench testing the CNC head only flows about 1% more at highest flow levels. Which related to 12hp on the dyno. At bottom end flow the std head is about 12-14% MORE! How many hp LOSS did that relate to? We dont know because you didnt show that.
Therefore I would suspect the losses below 4700rpm are a lot bigger than the small gains above. Meaning this CNC porting was not worth while for a none race engine. Which is the opposite of your videos conclusion...that would seem disingenuous to your viewers.
You clearly didn’t watch the video all the way or cherry picked. If you had you would’ve seen the comparison at 4000rpm vs non Cnc ported head and Cnc ported heads with the Vic jr. The Cnc ported heads made more power at 4000 than non. Not only that the difference was growing at lower rpm meaning it was looking if I pulled the dyno lower the difference would have been greater in favor of the Cnc ported heads. This same trend was also seen on the 2970 and the 2892. So your conclusion is false. Nobody would claim this engine to be a street motor. Also 2000rpm dyno pull is almost pointless because no street car is under full load and wot at 2000rpm. If you tell me you are then you need to down shift. You are confusing part throttle driving which I don’t test.
Also the stock head didn’t out flow the Cnc head down low.
None. I watch David Vizard.
Ok
Cnc is just about money and time. Shit in shit out. In other words the original port design was average then it just copies the average design.