[PAUL K]

Originally Posted by slowbird

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?

They didn't on Jim's wagon!

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

[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

[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?

[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.