[Cliff R]

"Asking for a friend, how fast does THIS combination run at the track with different intake centerlines?

462 ci
10.2 CR
KRE D ports - 290 CFM
Crane 041 clone
RPM intake.

Thoughts if we had 310CFM heads instead, what would the engine like?"

NOT enough information to predict ET and MPH.

Anyhow, it's difficult to slow down a FAST car right to start with. How hard it leaves is the KEY player to ET. Once you get the car to leave hard the engine becomes a smaller part of the big plan. So each change we make that effects engine power has a very small impact on the results at the track. Like moving a cam, for example. Since you aren't killing off a bunch of power and shifting it more than anything else the vehicle still runs very close at any particular ICL position. You'd be lucky to see more than a tenth and 2mph moving ICL with most cams (assuming you have it correctly installed in the first place) going 4 degrees in either direction....IMHO

As far as camshaft choice, NOT enough camshaft to effectively use that much head flow in a 455CID build so more head flow isn't a big player.......

[Formulajones]

I agree the 041 is not enough camshaft in a 455 to take advantage of heads that flow ~300 cfm so adding more head alone won't do much of anything for the combo without a cam change.

I have however seen 455's with 041 cams and ported iron heads that flow 240-250 cfm that make 450-ish hp when dialed in if that helps give any idea.. That combo has been done to death.


How fast will it go? Like mentioned way too many variables to predict. 3200 pound car or 4000 pound pig??

I can tell you most guys around here with engines that should be making that kind of power can't get out of the 14's LOL. Either due to lack of tuning, lack of driving, and the fact that most street cars aren't really setup to use it effectively.

[pastry_chef]

Originally Posted by Cliff R

"Asking for a friend, how fast does THIS combination run at the track with different intake centerlines?

462 ci
10.2 CR
KRE D ports - 290 CFM
Crane 041 clone
RPM intake.

Thoughts if we had 310CFM heads instead, what would the engine like?"

NOT enough information to predict ET and MPH.

So the engine from post 31 was not "nearly identical" to the OPS 290 CFM heads?
I know you ran the Crower 60919 flat with iron d-ports around 240 CFM and cam was in at 109.

Originally Posted by Cliff R

I've tested the Crower RAIV cam in a 455 nearly identical to yours and found the best ICL was 109 degrees.

[pastry_chef]

Originally Posted by Formulajones

I agree the 041 is not enough camshaft in a 455 to take advantage of heads that flow ~300 cfm so adding more head alone won't do much of anything for the combo without a cam change.

I doubt this. Any dyno to back this theory?

I know of a very heavy (3900 lbs plus) hyd flat tappet car running 10.8 with 310 CFM heads. Granted an Ultradyne 239 is "larger" than the 041 but the car is showing way more power that most would think.

[Stan Weiss]

This analogy is how I look at. If I go to a bigger fuel injector (better flowing head) I need I shorter duty cycle (less duration).

Look at NHRA 500 ci Pro Stock engines today the are turning more RPM and making more HP than 25 years ago with less 0.050 duration cams because the heads are so much better.

Stan

[pastry_chef]

Originally Posted by Stan Weiss

Look at NHRA 500 ci Pro Stock engines today the are turning more RPM and making more HP than 25 years ago with less 0.050 duration cams because the heads are so much better.

Stan

I enjoyed an interview with Darin Morgan about two months ago, he made a similar point.

[Cliff R]

"So the engine from post 31 was not "nearly identical" to the OPS 290 CFM heads?
I know you ran the Crower 60919 flat with iron d-ports around 240 CFM and cam was in at 109."

I ran the Crower 60919 cam with the KRE heads as well.......FWIW.....

[Cliff R]

"I doubt this. Any dyno to back this theory?"

Yes, I built a 455 with early Edelbrock round port heads and it was DONE making power at 5100rpm's with the Crower RAIV camshaft. It did make good power however, 551hp and 550ft lbs peak torque. Even better it pushed a 3900' FB to 11.50's @ 118mph in full street trim with DOT's.

Remarkably, with smaller runner KRE heads it made peak power at 5600rpms. Nearly as I can remember 502hp and 567ft lbs torque.

These were different engines than the 455 that came out of my car for the HPP and Popular Hot Rodding Engine Masters articles, so try not to get confused when you try to Google all that up. For the record I built one of if not the first 455 to use their new heads and get dyno numbers on it. A few years prior to that I built a 455 with Edelbrock 87cc heads and dyno'd it at KRE as well. Both engines were very close other than the heads, KRE's vs Edelbrock.

The Edelbrock engine had a few more CID and used the 4.25" crank instead of the 4.21" crank, so it may have seen that as a slight advantage as well. Otherwise same cam, Rhoads lifters, high ratio rockers, and compression was very close as well.......FWIW......

[pastry_chef]

KRE heads, Crower 60919, 1.65 rockers. RPM intake.
502 HP @ 5300 RPM peak - sheet below.

Too bad the 60919 - E-head - 551 HP @ 5100 RPM dyno sheet is lost. E-head not benefiting from CFM, cam too small.. err..?
With the sheet we could also see the E-head's lack of "power carry" ?,
would drop to less than 502HP , well instantly I guess?. IMO suggests to an issue of some type.

[Formulajones]

And you can see how it is cam limited. All done at 5300, and peak tq to peak hp is only 800 rpm.

Not a terrible combo, but a waste of cylinder head for that cam. Would make more power everywhere with a better camshaft. We already know this, it's been done to death.

[Stan Weiss]

Originally Posted by pastry_chef

KRE heads, Crower 60919, 1.65 rockers. RPM intake.
502 HP @ 5300 RPM peak - sheet below.

Too bad the 60919 - E-head - 551 HP @ 5100 RPM dyno sheet is lost. E-head not benefiting from CFM, cam too small.. err..?
With the sheet we could also see the E-head's lack of "power carry" ?,
would drop to less than 502HP , well instantly I guess?. IMO suggests to an issue of some type.

Mike,
Do you have another dyno sheets from that engine. I don't like the way the fuel usage and BSFC has large peaks and valleys.

Stan

[pastry_chef]

Originally Posted by Formulajones

And you can see how it is cam limited. All done at 5300, and peak tq to peak hp is only 800 rpm.

Not a terrible combo, but a waste of cylinder head for that cam. Would make more power everywhere with a better camshaft.

That sheet in post 49 has KRE dports, not ported.
Fully agree, more potential is there.

How about 216 @ .050 .460 valve lift hyd flat with 290 CFM heads.
It made 495 HP @ 5400 RPM
Builder knows full well cam is choking it.
https://www.speed-talk.com/forum/vie...hp?f=1&t=63482
Drag test coming.

@Stan - only the one.

[Formulajones]

Originally Posted by pastry_chef

That sheet in post 49 has KRE dports, not ported.
Fully agree, more potential is there.

How about 216 @ .050 .460 valve lift hyd flat with 290 CFM heads.
It made 495 HP @ 5400 RPM
Builder knows full well cam is choking it.
https://www.speed-talk.com/forum/vie...hp?f=1&t=63482
Drag test coming.

@Stan - only the one.

I think we are on the same page, I just didn't explain it well enough earlier.

[pastry_chef]

Originally Posted by Formulajones

I think we are on the same page, I just didn't explain it well enough earlier.

I'd lean to something like this for a stock KRE dport.

[Formulajones]

That's sort of close to the cam that Paul spec'd for the last 455 I built.

[slowbird]

Originally Posted by pastry_chef

KRE heads, Crower 60919, 1.65 rockers. RPM intake.
502 HP @ 5300 RPM peak - sheet below.

Too bad the 60919 - E-head - 551 HP @ 5100 RPM dyno sheet is lost. E-head not benefiting from CFM, cam too small.. err..?
With the sheet we could also see the E-head's lack of "power carry" ?,
would drop to less than 502HP , well instantly I guess?. IMO suggests to an issue of some type.

Imo there's something wrong with that engine. If the cam is big enough to make peak tq at 4500 it should be more than big enough to carry power higher up. Id guess there is either a valvetrain, fuel, or air issue that limited peak hp

[pastry_chef]

Originally Posted by slowbird

Imo there's something wrong with that engine. If the cam is bigger enough to make peak tq at 4500 it should be more than bogger to carry power higher up. Id guess there is either a valvetrain, fuel, or air issue that limited peak hp

For the parts there, I think true peak torque should be no higher than 4000 RPM.

[Dragncar]

Originally Posted by Stan Weiss

This analogy is how I look at. If I go to a bigger fuel injector (better flowing head) I need I shorter duty cycle (less duration).

Look at NHRA 500 ci Pro Stock engines today the are turning more RPM and making more HP than 25 years ago with less 0.050 duration cams because the heads are so much better.

Stan

Just look at the power some of the LS engines are making stock. Large heads and intakes with not so big cams.

[Cliff R]

You can research this stuff to the brink of extinction but at some point you've got to close the laptop and head out to the shop and get dirty. It is the ONLY way to find out what works and what doesn't.

I fail to mention on many of my responses but I dyno just about every single Pontiac engine we've done here. With many of them, especially early on I'd take the time on the dyno to move cams, swap intakes, carbs, spacers, and everything related to making power and seeing what works the best with them.

I've even swapped out less important parts like spark plugs and distributors just to verify we didn't have any issues. Most of this happens when power numbers are down from where we think they should be. I'd add here that it isn't a perfect World out there and despite my best efforts it's common to get "spanked" some when it comes to this sort of thing. It's how we learn, or at least how I prefer to do it vs using the efforts of others and regurgitating the results in public Forum. Right to start with someone can very quickly point out that those results were NOT my own, or even done on the same dyno to insure accuracy/.

I'm also one of the only ones (far as I've seen) who has tested 3 different camshafts in the same 455 Pontiac engine with no other changes. Early in my learning curve I didn't mind buying the dyno time or spending the time/funds needed to figure this stuff out. No matter what software you own or how good your Google skills are it does NOT make up the difference from actually building these engines and running them on the dyno and backing up those numbers with track testing.

I call it "connecting the dots" and it is an essential part of the learning curve when it comes to these things........FWIW........Cliff

[Stan Weiss]

Originally Posted by pastry_chef

KRE heads, Crower 60919, 1.65 rockers. RPM intake.
502 HP @ 5300 RPM peak - sheet below.

Too bad the 60919 - E-head - 551 HP @ 5100 RPM dyno sheet is lost. E-head not benefiting from CFM, cam too small.. err..?
With the sheet we could also see the E-head's lack of "power carry" ?,
would drop to less than 502HP , well instantly I guess?. IMO suggests to an issue of some type.

Originally Posted by Stan Weiss

Mike,
Do you have another dyno sheets from that engine. I don't like the way the fuel usage and BSFC has large peaks and valleys.

Stan

Maybe a picture will show this better. OK I had sometime to type that data into my computer. This graph shows that fuel usage curve against another members fuel usage curve. The is just to show the difference in the shape of the curves.

Stan