Chevy 302 questions - Lateral-g Forums

jeepracer · #1 04-08-2012, 06:35 PM

hi, im looking to build a 302 chevy. i figured id ask a couple of questions befor i start buying parts. im looking to get as much h.p. out of it as i can. my question is, will stock 2.02 1.60 heads flow enough on a 302 to produce 500+ hp? i plan to get an aftermarket forged crank. aftermarket dome pistons. aftermarket rods. chevy 4 bolt main 350. and a roller cam. not sure what size the cam would have to be, if these heads would work. other option is to buy aftermarket heads and do anything to them. the reason id like to keep the heads stock is limiting factors for our classing. if i were to go aftermarket heads, how much hp could i get?

badmatt · #2 04-08-2012, 07:20 PM

invest in a good pair of heads WORKED for that particular combo if your looking for max squeeze.

Talk to a man by the name of Chad @ speier racing heads.

http://www.speierracingheads.com/

he can set you up with a cam and head combo that will make you more than happy.

jeepracer · #3 04-08-2012, 07:52 PM

looks like a great source.
One thing i forgot to add was, does anyone know specs on the trans am series 302's?

69x22 · #4 04-08-2012, 09:23 PM

Thats going to be tuff without a big solid lift cam and some compression. Are you putting this in a pro touring type vehicle or a drag race.
I remember the 302s in the old days had 5.13s, huge cams and turned some RPMs. Defiantly cool!

jeepracer · #5 04-09-2012, 03:37 AM

its actually going in an off road 4x4. the cars gonna be somewhere around 3300-3500 pounds. its all loose dirt and sand racing. a big solid roller is what i plan to use and i dont mind taking the rpms up

Rhino · #6 04-09-2012, 12:37 PM

Is there a class restriction limiting you to 302? If not, I'd get greedy and want a bigger bore.

There's rarely a replacement for displacement. Especially so when you're looking for torque.

carbuff · #7 04-09-2012, 01:28 PM

I would assume that there is a restriction, but if not, and you want the highwinding fun of a big bore/short stroke, go 377!

I built one for my Camaro and loved it! Spun to 7500 rpms easily, and with a T56 and 4.56:1 gears, it was a blast to drive.

Weeeeeeeee!!!!!!

badmatt · #8 04-09-2012, 03:10 PM

4.165" bore and 3" stroke... = 326 cubes.. that and a bad pair of heads... and some serious runner length= nutters. JMHO

jeepracer · #9 04-09-2012, 05:25 PM

theres really no set number that says what size engine you run, but the bigger the cubes the higher placed you are in the class. if i were to build a 377, it would probably place me in a class that is way faster. its very confusing...

theres drag racing and obsticle though. the drag racing is more heads up full throttle for 300 foot. where as the obsticle is more of a wide open/on and off for about a minute and a half, depending on the track. some tracks, there are really narrow turns and some have a couple hundred yards of space to race down. i feel that a high reving motor that is quick would be the best thing for it. there are many cars there running 283's that are at 7000 rpm for lond durations.

theres a guy that built one there that is a 302. he wanted to build a bone stock 302 and race it but he did some changes to it. it made, if i can remember correctly, 480 horsepower on alcohol. im not sure exactly on the internals but its pretty nasty. his runs really good but it has its week points and if i were to put better heads on it, i could make alot more. thats where the questions come in like what heads and the possibility of stock heads(worked). basicly the smaller the cubes the better, with alot of power.

i know alot of people say its a bad engine to build for what i do but i think its a really good combo. i wanna do this to kinda 1 up him too lol, for personal reasons that is

**GregWeld** · #10 04-09-2012, 06:17 PM

Okay -- so seriously -- building a motor is a lot more complicated than what you're asking.

Things like heads and flow rates etc have to match the cam choice - and the compression rate (static) and what RPM band etc (though you stated you want to see high rpms).

Thing like this need to be very well planned - particularly if you want to go racing and be competitive.

I wouldn't ask this stuff on a forum... you need to take your info - vehicle - weight - trans gearing - rear gearing - tire size etc to a REAL ENGINE BUILDER and tell him what you're after and see if you can do what you want to do.

Sound like fun!