New heads?
AJ, do the test yourself. I did the iron J to Edelbrock head swap. Never looked back. Remember, Squeeze his squeeze.
I started with a zero deck .030, 360. The J heads ratio was 9.8-1. 72 cc’s. Swapped on a Edelbrock 63cc head. Same fuel, went faster, no other changes, no problems.
IMO
Poor test
for a streeter.
First; because the smaller chamber Eddies jumped your compression up a full point, compensating for some of the heat loss,and so not an apples to apples comparison. And,
Second; because at WOT, for 11/12 seconds the heads can't get rid of all that much heat, compared to what is being created under it. And,
Third; for a streeter that mostly spends just a tiny tiny part of it's life at WOT and rarely more than 3 to 5 seconds atta time, and almost always from a too-low rpm, and often stuck at too low an rpm for most of the run, your test is meaningless. Throttled and at low rpm, the heads pump vast amounts of heat into the underhood, and need the pressure just to break even.
This is why, with aluminum heads, I ran a small cam, at near 200psi, and a minimum water temp of 205*F, and just rev'd the nuts off it at the top to stretch it out. Well that and 32mpgs US. I may be down on power at the race-track,but the fabulous lower register is waaaay more useful on the street, especially with a manual trans or street-friendly stall.
With a regular A833in low gear and 3.55s,20 mph is still only ~2300rpm. I'd rather have a boatload of torque there, than at some higher rpm and much higher mph, cuz every time I take off I will be going thru the lower register to get anywhere, and will be stuck below peak torque, all the way to ~34 or more mph.
And Lord help the poor guy that lets his carb ingest all that super-heated underhood air.
Maybe I misunderstood and this is for a drag-car. But I checked the Forum header............. this time;
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