[Formulajones]

Huge ports, hahaha

[p4msi1]

I don't know what all the fuss is about using a big port on the street. Most of us have 455ci+ engines. I just built a .060 + 455 for my son-in-law with 360cfm Edelbrocks. They are ported pretty big but show no signs of being sluggish at low rpm. It also fries the tires at 50 MPH in 2nd gear with 3.08 rear gears. I don't think iron heads can compare.

[Formulajones]

Agree, the last 455 we did for Dad had 330cfm round port Eddy's from kaufman. A hydraulic roller he specd that was 254/262 @ .050 and on the dyno it made 602 ft lbs and never dipped below 550 the entire pull. Peak HP was only 5800 so the talk of needing to spin it high isnt reality. It had a tight continental converter in it that only flashed 3000. It didn't need any rear gear, it made grunt right off idle and would yank the tires at the track. If people have trouble making torque with combos like this something is wrong.

[PAUL K]

Originally Posted by Formulajones

Agree, the last 455 we did for Dad had 330cfm round port Eddy's from kaufman. A hydraulic roller he specd that was 254/262 @ .050 and on the dyno it made 602 ft lbs and never dipped below 550 the entire pull. Peak HP was only 5800 so the talk of needing to spin it high isnt reality. It had a tight continental converter in it that only flashed 3000. It didn't need any rear gear, it made grunt right off idle and would yank the tires at the track. If people have trouble making torque with combos like this something is wrong.

What did that car run in the 1/4?

Recall the sixty foot?

[Formulajones]

Originally Posted by PAUL K

What did that car run in the 1/4?

Recall the sixty foot?

1.57-1.59 60's ET was 11.50's at only 115 mph. Race weight was 4120 lbs at that time. It didn't make a ton of HP despite what people think of big heads and big cam. It dyno'd at barely over 500hp at peak, but what it did really well was make torque. I don't really think a tight 2000 converter would have hurt it much, maybe slow the 60 down a smidge but drivability would be the same as the snug continental that was in it was pretty tight on the street anyway.

My Chevelle right now is setup similar to what you speak of. Currently has a converter that only flashed to 2100 at a recent track outing. Hughes wants to restall it which I'm fine with, but it still went 1.57 60 foot at a 4140 lbs. race weight and has a set of 360cc intake runner heads on it. I don't spin this one tight either, shifting at 5800. I'm actually fine with the performance it's shown so far and am in no hurry for a free restall from Hughes. In fact, it drives so good I may just leave it alone because it's already almost a full second under the roll bar rule as it is.

In short, I can set these cars up with bigger heads, bigger cams, with no need to spin the guts out of it, no need for 5000 stall converters or 4.88 gears, and they drive like a cadillac on the street with tons of off throttle torque, and using big single plane intakes to boot. When you have 4.210 cranks or 4.500 cranks, you almost really can't kill enough torque out of these things.

Another example would be that little 327 I recently did for my son. When I put the engine in the car I gave him a little TCI 11" converter I had laying around that flashed around 2500 when I used it. In his car it only flashed to about 2000 at the same track outing. I also only put a 3.25 gear in the car because it's a 3 speed and he daily drives it, sometimes 200 mile round trips on the weekends.
You would think a 327 with 195 heads would be high strung and run like crap below 4000 rpm. Not the case. While I have no doubt it would run even better with some gear and certainly some more converter in it as most cars will respond to that, he's already stoked at how well it's run already. 12.40's at 112 mph in street trim. There are many bigger inch Pontiacs in our area that can't run those numbers, big heads or not. When he does an overdrive in the car, I'll likely put a little more rear gear in it, and Hughes will do a custom lockup converter that will probably flash higher but keep drivability, and actually drive better than it currently does, yet will certainly run even quicker at the track.

[Jay S]

Here are screen shot of Jim Hands actually results with the KRE’s written by him.

When he pulled the KRE’s he went back with 6X heads and found another 10 or 15 cfm over what he had before. I think Stan has them listed in his data base, they flowed into the 260s. The time slips are from the 6x heads after the KRE’s. Jim had #64 head which flowed about this same 253 number. Rocky Rotella has one, he showed it to me, it was leaking coolant was why he quit running it. I am not sure if that is when he tried the KRE’s.

After the KRE’s he ported some 6X heads that flowed well into the 260s, which is also when his car was the quickest. The comparisons were also with the same Bullet cam. It used pretty aggressive HFT torque profiles on the intake. When it went back to 6x heads he went back to his old Wolverine cam. Time slips are with the Wolverine.

[Stan Weiss]

Originally Posted by Jay S

Here are screen shot of Jim Hands actually results with the KRE’s written by him.

When he pulled the KRE’s he went back with 6X heads and found another 10 or 15 cfm over what he had before. I think Stan has them listed in his data base, they flowed into the 260s. The time slips are from the 6x heads after the KRE’s. Jim had #64 head which flowed about this same 253 number. Rocky Rotella has one, he showed it to me, it was leaking coolant was why he quit running it. I am not sure if that is when he tried the KRE’s.

After the KRE’s he ported some 6X heads that flowed well into the 260s, which is also when his car was the quickest. The comparisons were also with the same Bullet cam. It used pretty aggressive HFT torque profiles on the intake. When it went back to 6x heads he went back to his old Wolverine cam. Time slips are with the Wolverine.

Does anyone know if the port center line length of the Iron and KRE heads is the same? If I had more information I could do some more calculations.

This is CFM per 1 cc of port volume for each head.

► 253 / 165 = 1.53333

► 273 / 186.5 = 1.46381

Stan

[Jay S]

Originally Posted by Formulajones

Agree, the last 455 we did for Dad had 330cfm round port Eddy's from kaufman. A hydraulic roller he specd that was 254/262 @ .050 and on the dyno it made 602 ft lbs and never dipped below 550 the entire pull. Peak HP was only 5800 so the talk of needing to spin it high isnt reality. It had a tight continental converter in it that only flashed 3000. It didn't need any rear gear, it made grunt right off idle and would yank the tires at the track. If people have trouble making torque with combos like this something is wrong.

That is interesting, what was the peak power at 5800? A 455 using 330 cfm running about 104% VE should carry a 455 past 7000. Seems like with that much cam it should have carried the power longer? Are those the same heads that are on your dads car now the big engine?

[Steve C.]

"Any back to back comparisons like Jim made going from iron to aluminum and back to iron?"

For interest here does anyone have the results with Jim Hands testing doing the swap and numbers involved. What aluminum head was involved..
TKS.

.

[PAUL K]

Originally Posted by Steve C.

"Any back to back comparisons like Jim made going from iron to aluminum and back to iron?"

For interest here does anyone have the results with Jim Hands testing doing the swap and numbers involved. What aluminum head was involved..
TKS.

.

Going from memory the car was running 11:50ish and it lost about a tenth with the aluminum heads. I think there was a slight mph gain with the aftermarket heads. It was a KRE aluminum d-port and a 250+cfm iron head

Its an excellent example of comparing "port volumes". The larger port volume heads made more power but couldn't run as quick.

Exactly why a well tuned 71 Trans Am will run away from a 336 geared LS-6 Chevelle.

Also a great example why "port volume" matters

[Steve C.]

Thanks Paul.
For some reason I thought Jim had tested Edelbrock heads.

I only had one "455" combo with Edelbrock heads to mention here as an example.....

4.210 stroke / 462 CID
XE solid roller with 254 at .050" intake duration
Edelbrock heads / 313 cfm at .600" lift
Performer RPM intake / HP 950 carb
2-inch headers
Depending on the dyno sheet at 3200 rpm it was at or approaching 500 ft.lbs. torque. Peak torque was at 4400 rpm with 589.1 ft. lbs. and carried over 500 ft. lbs all the way to where it made peak power at 5800 rpm (580 hp).
The compression was only 9.7 so pump gas was certainly not an issue and it was driven on the street with NO issues being sluggish off idle or at lower rpm.
Best performance with that combo was 10.88 at 124.28 mph

.

[slowbird]

Originally Posted by PAUL K

Going from memory the car was running 11:50ish and it lost about a tenth with the aluminum heads. I think there was a slight mph gain with the aftermarket heads. It was a KRE aluminum d-port and a 250+cfm iron head

Its an excellent example of comparing "port volumes". The larger port volume heads made more power but couldn't run as quick.

Exactly why a well tuned 71 Trans Am will run away from a 336 geared LS-6 Chevelle.

Also a great example why "port volume" matters

A properly done set of kre d-ports with stomp iron heads imo. The kre heads Jim tested were out of the box from kre weren't they?

[Skip Fix]

My pump gas motor in the 78 TA has KRE 320 cfm CNC heads on it and a 239/247 @ 0.050 and has lots of bottom end with the Continental convertor. And has run 10.90s @124 in good air!