[slowbird]

Originally Posted by PAUL K

They didn't on Jim's wagon!

I thought they were cleaned up but definitely not ported. I'm thinking they flowed around 285.

I'll put money that no iron d-port will keep up with a set of properly done alum d-ports. I don't think Jim's test was a fair test. Jim was heavily vested in iron, he didn't want the alum heads to out perform the iron.

[jerry455]

I don't know how any 455+ is going to be lazy on the bottom end. My 455+.030 with 4.250 stroke crank with Edelbrock 80cc RPM heads is amazingly responsive and only with 3.08 gears, so far. I have a Crower hydraulic roller at a little over .618 lift, and it is a blast to drive. Have not had it to the track yet as it still has a stock THM 350, updating this winter, and don't want to break it. The engine made 577HP and 580 tq. 3600 rpm up over 5800 rpm was over 500 ft lbs.

[Steve C.]

KRE's New Aluminum Heads: At the Track
published Nov 02, 2004

"HPP was invited to observe as these new heads were tested against a set of 6X heads on the same dyno on the same engine, which happens to be a 468 cubic-inch (455 +.060) Pontiac out of Q-jet-builder Cliff Ruggle's '73 Ventura. The idea was to see the difference in results with the only change being the new KRE heads; everything else would remain the same, and testing would be done on the same day under the same conditions."

https://www.hotrod.com/how-to/0502po...-track-results

After this testing, about two years later. Comments made by Cliff, posted for interest here, and some of which relate to points made here in this thread....

My personal assessment of the KRE heads. There is more power at every rpm by the "seat of the pants" evaluation, the dyno also reflects this. Idle quality improved, from the higher static CR and probably some due to the improved chamber design. The engine is equally as smooth right off idle, if there is any loss of part throttle power at low rpm's it is not detectable. I DO feel a loss of low rpm power if a 1" spacer is added, and the track times reflect this with slower 60' times, but we run almost 2mph faster (back to back test).

I may not "feel" any losses off idle and low rpm's simply because we have the cam advanced to 109 ICL, and the car is relatively light, 3760lbs with driver, it moves out pretty easily at light throttle. It is also very finely tuned, the carb and distributor settings are perfect, I've never driven a fuel injected car that was equally as smooth for "normal" driving.

Recently, we managed to extract some additional power from the combination, it took a hydraulic roller cam and RPM intake to do it. The info is posted on our cam testing thread. We certainly learned a lot from it. Many folks wonder why we stuck with such "small" cams and didn't simply install a 250/260 flat solid or much bigger hydraulic roller? No doubt we would have seen more dramatic increases in the peak power numbers. Even so, the goal is to increase power in the rpm range we run the engine in, NOT to make the "big" peak power numbers for bragging rights. Any loss or shift in power was not wanted, we leave the line just over 3000rpm, shift around 5000rpm's and go through at 5100-5200rpm's. Leaving "softer" and finishing harder isn't going to cut it, and we were NOT up for any gear and/or converter changes. Also keep in mind that we are testing the unported version of the KRE heads, not the ported versions as mentioned in this thread. Next time around we are up for some port work, but that's at least a year if not two out.....Cliff

[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.

[PAUL K]

Originally Posted by slowbird

I'll put money that no iron d-port will keep up with a set of properly done alum d-ports. I don't think Jim's test was a fair test. Jim was heavily vested in iron, he didn't want the alum heads to out perform the iron.

I'm up for it if you want to sponsor the test.


What part of Jim's testing do you find fault with?

[PAUL K]

I think folks are missing the point of this thread. I don't think it's about whether a 455 can make power, I believe it's in regards to the effect of port volume on a combination.... But maybe I'm mistaken.


Anyone have any examples of port volume changes and it's effect on performance?


Anyone remember when Pete McCarthy ran faster with his small volume 670 heads than he did with the better flowing and bigger volume RAIV heads? Any thoughts if even bigger heads would've degraded his performance more?

[Stan Weiss]

Does anyone know at what lifter raise the wolverine Adv. Duration is at? Other that that the cam cards look very close.

Stan

[Dragncar]

Originally Posted by slowbird

I'll put money that no iron d-port will keep up with a set of properly done alum d-ports. I don't think Jim's test was a fair test. Jim was heavily vested in iron, he didn't want the alum heads to out perform the iron.

Remember Jim Roberson did up a couple pretty wild pairs of 48s.
Made 806 HP with one set and the other went 340 cfm. Tons of epoxy for sure.

[PAUL K]

Originally Posted by Stan Weiss

Does anyone know at what lifter raise the wolverine Adv. Duration is at? Other that that the cam cards look very close.

Stan

Stan that grind originally came from Crane. They used 294/304 @ .0054 tappet lift

[ta man]

Originally Posted by PAUL K

No port volume.... I screwed that up, haven't had my coffee yet.

I'm guessing your heads are about 210cc .... So let's say a theoretical 190cc head and a 260cc head?

I'm a tuner more than a builder..but my guess would be there would not be a lot of difference. That being said there is more power potential with the 260cc head if they do flow much more as they should.

[Steve C.]

"Like all other aspects of engine building, port size is relative to the required airflow of the engine. The smallest port that will deliver the airflow needed by the engine is desirable. That means we will have excellent velocity for port filling, but without any choke that may limit required peak airflow. The needed airflow depends on engine displacement, RPM, and VE at that RPM. And a port big enough to deliver 400 cfm may well be too large for any engine that can only use 300 cfm."

Jim Hand

https://www.youtube.com/watch?v=CmfxHNxk8ew


.

[Jay S]

From what I recall Jim Hand was not of the opinion that Aluminum heads provide an octane advantage for increasing the compression on pump gas. That was why he did not increase the compression much with the KRE heads. I think he was both correct and incorrect on that idea. So long as the heads are identical, every test I have seen changing from Aluminum to Cast Iron has not shown any difference in octane tolerance or power. I think Jim was correct on that idea. But where I think he was incorrect is that a port volume increase does generally allow for more cylinder pressure on the same octane. I suspect increasing port volume moves air flow to where piston speed is faster, likely also leads to a cooler air charge, and also tends to move some engine scavenging around so the power band gets shifted a little higher of spread out. Depending on the car, some of those things will not necessarily improve the engines performance. If you could replicate an iron copy of a KRE or Eddy head, i think the Iron heads would run identical. The Iron to Aluminum contest to me more decide on how thick the castings are to manipulated them. The winner in that area is likely the Aluminum heads.

My 6X heads on my TA are ported to 185 cc. I tried 196cc on another set and lost 16 cfm at peak flow against the 185 cc head. I would expect the 196cc had more flow lift in it someplace, but I could not find it. Here is a couple photos of the 196cc 6X heads. The photo has a 1.77 valve that is sitting down on the valve guide stem.

[Stan Weiss]

Originally Posted by PAUL K

Stan that grind originally came from Crane. They used 294/304 @ .0054 tappet lift

Paul,
Thanks So the Bullet does have a better hydraulic intensity.

Stan

[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 PAUL K

I think folks are missing the point of this thread. I don't think it's about whether a 455 can make power, I believe it's in regards to the effect of port volume on a combination.... But maybe I'm mistaken.


Anyone have any examples of port volume changes and it's effect on performance?


Anyone remember when Pete McCarthy ran faster with his small volume 670 heads than he did with the better flowing and bigger volume RAIV heads? Any thoughts if even bigger heads would've degraded his performance more?

I think your thinking is exactly correct. I tend to think there are changes which could be made to overcome the port volume when it has a negative effect on performance. But they are not always obvious.

This port volume debate is not just with Pontiac’s. The same things like you describe with McCarthy frequently happen on BBC combos too. BBC heads have Rectangle, Oval, Peanut port, and the modern Roval. Sometimes the smaller port volume goes faster. Especially on the Rectangle to the Roval.

BB Mopar is the same way. Max wedge versus a standard port window the 30cc bigger Max wedge does not pick up as much HP as you would expect just by going by flow numbers.

[Jay S]

Originally Posted by PAUL K

Anyone have any examples of port volume changes and its effect on performance?

Pump gas combo that had a heads swap from stock E heads with minor port work to stock KRE high ports, close to the same compression, same cam. The car ran the same ET and MPH after the head swap, 11 flat. A couple cam changes and still ran the same times. Eventually the heads were milled and retarded the cam timing to get down to the mid to upper 10s.

[PAUL K]

Originally Posted by Jay S

I think your thinking is exactly correct. I tend to think there are changes which could be made to overcome the port volume when it has a negative effect on performance. But they are not always obvious.

This port volume debate is not just with Pontiac’s. The same things like you describe with McCarthy frequently happen on BBC combos too. BBC heads have Rectangle, Oval, Peanut port, and the modern Roval. Sometimes the smaller port volume goes faster. Especially on the Rectangle to the Roval.

BB Mopar is the same way. Max wedge versus a standard port window the 30cc bigger Max wedge does not pick up as much HP as you would expect just by going by flow numbers.

I agree and thanks, just trying to pass on free knowledge that will help an enthusiast make better choices.

Originally Posted by Jay S

Pump gas combo that had a heads swap from stock E heads with minor port work to stock KRE high ports, close to the same compression, same cam. The car ran the same ET and MPH after the head swap, 11 flat. A couple cam changes and still ran the same times. Eventually the heads were milled and retarded the cam timing to get down to the mid to upper 10s.

Thanks that's a good example. Seldom do I see Hi-ports offer an advantage over a nice pair of Edelbrock heads on factory block builds.

[slowbird]

Originally Posted by PAUL K

I think folks are missing the point of this thread. I don't think it's about whether a 455 can make power, I believe it's in regards to the effect of port volume on a combination.... But maybe I'm mistaken.


Anyone have any examples of port volume changes and it's effect on performance?


Anyone remember when Pete McCarthy ran faster with his small volume 670 heads than he did with the better flowing and bigger volume RAIV heads? Any thoughts if even bigger heads would've degraded his performance more?

My HP heads kept getting larger and hp and rpm kept increasing. CFM never really picked up much. In my case larger was better.

[Stan Weiss]

Originally Posted by slowbird

My HP heads kept getting larger and hp and rpm kept increasing. CFM never really picked up much. In my case larger was better.

Port velocity on a flow bench is one thing, and on a running engine is something else. While everyone talks about cfm for a give engine size, RPM and VE% you also need to have correct CSA.

Stan
.

[Jay S]

Pulled some stuff from your date base Stan, curious if there are patterns.

Is the KRE high port correct? Anyone have port cc numbers after porting like Slowbird mentioned? The higher port entry must effecting that one.

CFM per port volume

Stock D port Iron
211 cfm 146 cc. 1.445 cfm/cc
153cc. 1.39 cfm/cc
Jim Hand 64s
253 cfm. 165 cc. 1.533 cfm/cc
Jim Hand 6X-4
268 cfm 170 cc 1.57 cfm/cc
614 RA 4. Production
231 cfm 182 cc. 1.17 cfm/cc
614 RA4 bowl porting
252 cfm. 186 cc 1.354 cfm/cc
197 455 HO, deep 60* valve cut
243 cfm. 174 cc. 1.396 cfm/cc
6X 2.125” ported
292 cfm. 196cc. 1.48 cfm/cc
Edelbrock round port 72cc
282 cfm 215cc. 1.31
Edelbrock. STEVE C
317 cfm 227 cc. 1.396
Edelbrock SD performance 2.19 race
333cfm. 235 cc. 1.428
Edelbrock D port
272cfm 185cc.HHP. 1.47
KRE D port Jim Hand
273 cfm. 186cc. 1.47
KRE D port 295 CNC
290 cfm 197 cc. 1.47
Edelbrock Wide Port 2.18
375 cfm. 255 cc. 1.47
KRE High Port OTB w/valve job 2.20”
330 cfm. 277cc. 1.19