We just built a 400 pontiac for our cruiser car, wish we could use chevy, but this is what we have. A 72 block, not bored, 4 valve relief flat top pistons, #13 heads with the 2.11 intake and 1.81 exhaust. Triple angle valve job, titanium retainers, bronze guides, craine racing springs, crane cam with 465 lift, 112 lobe seperation, ram air 3 intake, not ported or anything fancy, 4 barrel carb. Our compression is not quit 10.5-1, but close. Just a good estamate would be great.
I know I know, Chevys are cheaper to build...but seeing a Pontiac motor anymore is way cool. by the way, when you say cruizer car... is that a stock car class...or cruizer,as in a driver ? anyway, need to know cam duration @ .050. Thanks John
I dont get it. Stock hp from 70 gto ram air 3 was 366-370hp. So why is mine so much lower when I have ram air 3 heads (which are 72cc) with 10.5-1 compression and intake with a 4 barrel carb and a bigger cam. Just confused.
youll have an easy 360hp what you have is a ram air iii with a high lift cam it cant reduce hp.
ram air iii chamber volume is much smaller than on that dyno sheet your cumustion chamber is 72 cc not 86 or whatever is on there..thats a hell of a difference.
on the dyno, i used what info i had.. it should be close if parts are right.
you did not show what type of intake it had, that can make a big difference in high rpm horsepower.
you also did not say the size of the carb.
in the compression math i had @ 73 cc chamber to get you to the compression you stated.
i put in a 800 cfm and a different intake, adjusted the heads
you will like this better, as you can see everything makes a diiference
He did tell us what heads and intake he was using, and we know it isn't going to be making power up that high anyway. I never said it was stock, I was just pointing out that revving this thing up to 6500 is a little pushing it.
You know about the Ram Air 3 heads all done right. the carb is a rebuilt with some goodies 750cfm quadrajet. Everything is new in the bottom half, arp bolts and better studs throughout.
We ran it to 5,400 rpm and that was all we needed, plus I think we have a bit more if it came down to a shoot out to the finish line.
I want to get more, but still have to stay close to stock, like fricken exhuast manifolds, I should port them and the intake if I could get by with that, na maybe just the exhuast. How about some copper head gaskets or shaving then a couple thousands.
Yeah, 6,000 rpm is to much i think too, thanks for all the good info on here, alot of very helpful guys.
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