z28crazy

well ive gone and done it. I blew up the top end of a motor i thought i couldnt break. Sad i know but it means i get to rebuild it even better and with more power!

I have a 350 4bolt main @ .040 out. 356ci.

forged bottom end with eagle crank and rods arp bolts and speed pro pistons. 10.5:1 compression. i have a crane cams cam with a 502/512 lift. its a very torquey cam; picked it to compensate for my long gears. using an edelbrock rpm dual plane manifold and rochester quadrajet for a carb and a stock distributor with H.O. coil.

i recently bent two push rods, broke a hydraulic lifter and bent a valve. thankfully there is no damage to the head its self.

The heads are a pair from a 90 corvette. aluminum.
i want to if possible utilize the same heads but work them if possible. i also want to use the same cam.

my question is what would be good upgrades to do at this point?
port job? new manifold? different carb and distributor?
i would love more power. i can sacrifice streetability for track ability. any opinions are welcome. and emissions are no longer an issue, so dont worry about that.

thanks

red406

iTrader: (4)

What caused the top end to "blow up"? I'm not sure if stock heads can handle that much lift. You might need to have some machine work done to the heads to avoid this mess again.

F-BIRD'88

The cam will be trashed.
The heads in stock form are very modest in flow.
198cfm. But can be fully ported to 260cfm with larger Lt4 valves 2.00" 1.56"
At that point they will make serious power.
Fully porting these heads involves modifing the combustion chamber as well. Lingenfelter Racing offers a complete CNC ported head on an exchange basis. Unless you're willing to do all the porting work yourself, you should price compare a new set of aftermarket heads. Sell your heads off as good used cores. Unless you're only looking for a modest increase in power you'll want to recam the motor once the heads are done.
You have a serious valvetrain interference problem.
Probabily the spring retainer crashed into the top of the guide at rpm. Either you seriously overreved the motor and floated the valves or there is not enough clearance between the parts, or both.

z28crazy

the melt down was a result of of a few over revs. spring fatigue led to the demise of several parts.

both replys say that i will have to "re cam"? are you suggesting that i get a new cam with a different profile? or i have to get a new cam bc the one being used is trashed now?

anyone have specific combos with power numbers?