Starting this to get away from hijacking another thread.

What kind of power can you get from a pump gas big block with the Edelbrock Performer RPM Chrysler 440 heads? Mopar Muscle Magazine asked that in 2009. They invited a few guys to come and play at Comp Cams for a week and we were invited.

For some back ground to what we brought you must go back to 2005. My son Cody was reading through some old automotive magazines and came across a December 1982 issue of Popular Hot Rodding that had an article on a 630HP 440 his grandfather had built. He said to me, "Hey, Pop did this in 1982! Can't we do something like this NOW?"

"Yes", says I, "But we need cylinder heads. Your grandfather told me there were three secrets to making horsepower. The first two secrets are cylinder heads. The third secret, and the most important, is CYLINDERHEADS!"

We had nothing but old cast iron heads and Cody began destroying them. We had scrap iron pile of sawed, ground, drilled and ported heads when he brought to me a pair of 452 heads that flowed around 290 cfm. He said, "What about these?"

Those will do boy, those will do.

We built our first engine together. It was the same short block we took to Comp Cams in 2009. But in it's first configuration it went like this.

400 block
Factory 440 forged crank
Scat H-beam rods
Ross forged flat tops
9.5:1 compression
Comp XR292R solid roller
M1 single plane
950 cfm Quick Fuel 4150

On March 3, 2006 she dyno'd 588 lb-ft @ 4600 rpm and 621 HP @ 6100 rpm. We didn't catch Pop, but we had come close.

The engine went into a '71 Road Runner and drove around on the street for awhile. Then in 2008 it came out and got 906 heads and a different cam and went back in the 'Runner and went to Westech performance Group in Mira Loma, California where it dyno'd 554 HP to the rear wheels.

Then came the 2009 Amsoil/Mopar Muscle Magazine Engine Challenge. We applied and were invited. The contest required the use of 93 octane and Edelbrock RPM heads. So I bought a pair of RPM's and gave them to Cody, "Make 'um flow son, we are going to show them what we can do."

The build?

Freshened 2006 451 short block
Erson Custom solid roller
Comp Cams lifters
1/2 Harland Sharp, 1/2 440 Source rockers, left overs, going cheap.
Cloyes timing chain
Crower 68670S valve springs
Single plane Indy Intake
2" HVH SuperSucker
Pro Systems 1140 cfm Dominator
Edelbrock RPM heads, 349 cfm @ .800"
11.7:1 compression

A few 451 motors ran before us and made 585-590 HP. We were asked what we would make the next day and I said, "700+".

Ah HAH, HAH, HAH, HAH! We were the joke of the evening at a dinner we weren't at that night. Until the next day.

At 600 rpm/sec pulling a mechanical water pump it went 723.4 HP and 568.8 TQ. The only engine to beat us was a 500" wedge that made 724.5 HP.

So what horsepower can you make with RPM heads? I don't really know for SURE. But, we went home, changed the cam, put on an electric water pump, pulled the engine at 300 rpm/sec and she went 600 lb-ft and 787 HP. The little 451 made 503 lb-ft of torque @ 3500 to 575 lb-ft @ 7200 rpm where we shut it down.

With the RPM heads, it made 19 pulls over 1-1/4 days of dyno testing with mechanical and electric water pumps, loads ranging fron 300-600 rpm/sec and made 743-787 HP on every pull.

I've just googled the challenge, that is a pretty impressive motor, it's a shame it wasn't in a well set up car, to see what sort of numbers it might have run.
Mick

Gotta love those lowly rpm`s.............. ESPECIALLY when you can be faster than some of the higher flowing units although the whole car can be the difference. Good stuff.........

I have followed you guys since that first article came out. How do I contact you about doing a new set of performer rpm's?

I have a 431 begging for great heads.

I sent a PM with contact information.........at least I think I did.

Thanks for the info! I will be in contact shortly.

You need the engine to rpm, the Eddy heads port cross section just doesnt allow that. Combine that with a long stroke, its more of a torque monster than a high hp engine.. You cant hardly get more than 6200 rpm out of those heads. Id say it can be done, guys are claiming 340 cfm from ported Eddy heads on here, although Im skeptical of those claims...
Anyways, go with a largest bore and short stroke, have the heads ported to thin air, utilizing as close as a max wedge port openiong as possible, and have some one custom grind a solid roller...
Throw as much compression as you can get with those huge chambers, and use alky injection. It will run and run well. Turn the engine to 7K

With all due respect Wayne, they didn't do that. They got 723 hp with a flat tappet, 11.1 comp and 93 octane, after the contest, they swapped the roller in and got 787 hp.
My engine is higher comp, 76 cc heads flow .320 and i would say it's not much more than 600hp.
However, i realise there are certain things they do in these contests to get a win which may not be conducive to engine longevity.
Mick

Old schoolers have been figuring out ways to make big inch Mopars turn High RPM's despite being severely under ported for 50 years now

When the port is small the velocity goes way up, to some extent the old "trick" was to over-cam it , over squeeze it and put a big intake manifold runner on it to minimize the bottle-neck. Also when a motor is under ported, longer rod ratios are really your friend at RPM's above the torque peak (helping you hang on to torque as long as possible).

That said, I have absolutley no doubt you can get well over 700 through an Eddy with porting AND with the right combination of other parts....but that being said for 500" with the max wedge choices that are out there....other than as an engineering exercise or for a contest, why would you sink that much extrs porting $$$ in the Cross sectionally limited Eddies when so many other heads are available for less overall $$$.

Great thread! Gotta love old school!!

We used a solid roller in both the contest and afterwards. The more load we placed on the engine, the more power it made. I think the biggest difference after the contest was the load on the engine and the electric water pump.

As to the engine rpm. We were required to pull the engine to 7000 rpm during the contest. On the final run of the competition we pulled some timing and lost power, about 10 HP. After the contest, while still on the Comp dyno, with the retarded timing and without the air director on the carburetor, we made an exibition run to 7600 rpm. At 7600 rpm it made 726 HP and the curve was still trending upwards.

Good post. Good tech.
I've got some 750hp iron heads in garage right now i'm putting on a 383... I'd like to make a post , but the "customer" is a bit shy, mr. secrets.

Jim you do not say what size cam you were running, so I am going to asume it was over 280@50 since it was still pulling over 7600 RPM. Am I close? I stepped down from 282@50 to a 266@50 with same lift and it made almost the same power up to 6500 RPM. My heads flowed 304@700 lift

I'd be interested in knowing more about those max'd out RPM heads, stuff like runner volume, port entry size, CSA, valve sizes (bigger than 2.14?), in addition to the flow #s I think were posted on a different thread. IIRC I've known at least three cars that have run in the 9's w/ 'em, so they're effective, even if not flashy or hi-tech.

i believe they had 2.25" intakes and stock exhaust in them, i'm also guessing they had a fairly large stick in that engine.

2.25 valves, 1.6 rockers, 700+ roller cam, no welding or epoxy in heads.
Mick

we've never had this engine on the pump, but at 5.91 and a little over 116mph, 2850lbs. i believe that is about 700hp. that's with a flat tappet and rpm heads.