[Dlaw455]

Looking for some feedback on my Wide Port Edelbrock heads CNC ported by a reputable Pontiac shop. I know flow numbers aren't the only indicator of performance but that aside, I'm wondering if these can be improved upon by someone or are they pretty much as good as they can 'reasonably' get? They have 2.25" intake valves and 1.74" exhaust valves and the flow #s are as follows int/exh cfm at 28":
.200: 148/131
.300: 216/172
.400* 275/204
.500 326/227
.600 349/241
.700 371/251

I also have a port matched victor 4500 efi with plenum work I paid alot for and the plenum work looks like they put 1 hour into it so looking to match that to overall head performance.

Cam has gross lift at .693" as it does get driven on the street.

[steve25]

What times does the vehicle run at the track?

I would very much suggest that you get the heads flow tested with the intake bolted on and then again another test done with the carb / EFI bolted to the intake .

I get the notion that flow wise your not even fully utilizing what you have in terms of those heads now.

I really can’t see that Transmission living for that long if that motor ever get to the point of putting out what it can, I also can’t see why a expensive build like that was not dyno tested especially so due to getting the EFI base lined.

[slowbird]

Paul Knippen can get 380+ cfm and fix the intake for you. He fixed my Butler/SD wide ports and did the intake. Made around 850hp on 92 octane and 11.2:1 compression. I've been driving it quote a bit on the street.

[Dlaw455]

Originally Posted by slowbird

Paul Knippen can get 380+ cfm and fix the intake for you. He fixed my Butler/SD wide ports and did the intake. Made around 850hp on 92 octane and 11.2:1 compression. I've been driving it quote a bit on the street.

Thanks slowbird! I actually talked with Paul about the intake before but unfortunately he was backed up for months so I took another route as it was the beginning if this season. Now that we're coming into winter here in MI I figure I can get some better work done.

[Dlaw455]

Originally Posted by steve25

What times does the vehicle run at the track?

I would very much suggest that you get the heads flow tested with the intake bolted on and then again another test done with the carb / EFI bolted to the intake .

I get the notion that flow wise your not even fully utilizing what you have in terms of those heads now.

I really can’t see that Transmission living for that long if that motor ever get to the point of putting out what it can, I also can’t see why a expensive build like that was not dyno tested especially so due to getting the EFI base lined.

What makes you think a 525 winding out to 6500 rpm won't use all that head flow? I'm sure it would take 400+ cfm if the heads would flow it And the trans is an Art Carr unit for 1000h.p. applications so its fine. I am getting a chassis hub dyno tune in the spring but at $1000 a session I want the head and intake work done first. Injection is multi port with Wilson 4500 throttle body and cnp ignition managed by Terminator X.

[ponjohn]

Originally Posted by slowbird

Paul Knippen can get 380+ cfm and fix the intake for you. He fixed my Butler/SD wide ports and did the intake. Made around 850hp on 92 octane and 11.2:1 compression. I've been driving it quote a bit on the street.

Solid roller?

[steve25]

The difference between a 8 cylinder motor ingesting 371 cfm@ 28” @ 100% VE and 380 cfm@100% VE is 18 HP.

[PAUL K]

18 horsepower gain can be considered a lot or not much. Depends on the application and nature of the owner. Since this is the race section I'd think it should be considered a lot.

Fwiw I've improved several sets of commercially available "wide ports" and the overall combinations picked up a lot more than 18 horsepower even though in some cases the CFM changed very little ..... fwiw

[steve25]

I don’t doubt that you have done nice improvements over other folks stuff for 1 second Paul, all I am alluding to in a way is that once a NA motor gets to the 750 HP level those additional 15 to 25 HP gains can get very expensive if a motor has already been flogged on a dyno to get to the power level it’s currently at.

[Dlaw455]

Originally Posted by steve25

The difference between a 8 cylinder motor ingesting 371 cfm@ 28” @ 100% VE and 380 cfm@100% VE is 18 HP.

Agree with you there. About 2hp per cfm and definitely not worth messing with the heads for that little. BE on this motor according to injection data is around 120% and it's using around 410lbs fuel/hr at 6500rpm and wot.

[Dlaw455]

Originally Posted by ponjohn

Solid roller?

Yes. 268/275 comp hitec series roller cam with .420 lobe and 112 LS.

[Dlaw455]

Originally Posted by PAUL K

18 horsepower gain can be considered a lot or not much. Depends on the application and nature of the owner. Since this is the race section I'd think it should be considered a lot.

Fwiw I've improved several sets of commercially available "wide ports" and the overall combinations picked up a lot more than 18 horsepower even though in some cases the CFM changed very little ..... fwiw

Yeah not all about flow or even peak flow for that matter. I'll hit you up on messenger again. It was march when we last spoke....

[PAUL K]

Originally Posted by steve25

I don’t doubt that you have done nice improvements over other folks stuff for 1 second Paul, all I am alluding to in a way is that once a NA motor gets to the 750 HP level those additional 15 to 25 HP gains can get very expensive if a motor has already been flogged on a dyno to get to the power level it’s currently at.

I agree, not long ago a fellow enthusiast purchased a used but proven top shelf Pontiac engine and sent it to the wrong shop to be freshened. First thing that shop did was dyno'd the engine to verify the power. Then told the guy they could change a bunch of stuff and make great improvements (this engine just dyno'd around 1200hp NA) got a large deposit from the fellow and did nothing. Several months later and a good lawyer the motor was reassembled (with a bolt left in one of the cylinders) and sent to another shop. It's easy to claim big improvements and a lot harder to achieve them.

Btw I wasn't boasting about making improvements, my point was the power gains came without an improvement in CFM measured with a flow bench.

[steve25]

I’am a little leery of that 120% VE number on a motor of under 12.5 comp and with as you have posted running a Intake that does not look like much work was done too it.

[Half-Inch Stud]

Air inhale is almost everything. The ideal Fuel atomization for max power is also important.

I used to be anti-fuel-injection for max power because fuel injectors ranged from Barrel-Valve thru throttlebody injection. Yet turns out optimal fuel atomization needs to be a certain size: for sake of descriptive discussion; much larger than fog, much smaller than dew.

So that port fuel injection, timed with Inhale valve event can ALLOW an advantage over the venturi-restriction carbs.

This Race Section ought have a development on home-eval of injetctors, that concludes what the optimal outlet design needs to be for max HP.

[Dlaw455]

Originally Posted by steve25

I’am a little leery of that 120% VE number on a motor of under 12.5 comp and with as you have posted running a Intake that does not look like much work was done too it.

Yeah the holley VE numbers do seem a bit overly optimistic.

[steve25]

I have never looked at the Holley info, but in general if your looking to get above 118% VE you need big race compression and a well worked out tuned length duel carb tunnel ram.

And a well spec’ed Cam goes without saying.

[Dragncar]

Originally Posted by PAUL K

I agree, not long ago a fellow enthusiast purchased a used but proven top shelf Pontiac engine and sent it to the wrong shop to be freshened. First thing that shop did was dyno'd the engine to verify the power. Then told the guy they could change a bunch of stuff and make great improvements (this engine just dyno'd around 1200hp NA) got a large deposit from the fellow and did nothing. Several months later and a good lawyer the motor was reassembled (with a bolt left in one of the cylinders) and sent to another shop. It's easy to claim big improvements and a lot harder to achieve them.

Btw I wasn't boasting about making improvements, my point was the power gains came without an improvement in CFM measured with a flow bench.

Well, if someone has a 1200 HP NA Pontiac, there is not much "wrong" with it !
If you do not mind, what top end was on it ?

[PAUL K]

Originally Posted by Dragncar

Well, if someone has a 1200 HP NA Pontiac, there is not much "wrong" with it !
If you do not mind, what top end was on it ?

Tigers