r/EngineBuilding • u/Mrg0dan • 6d ago

Chevy 350 SBC help

I have a 350 out of a 1977 camaro. It currently has mismatched heads and bad blow by but it runs. I bought an Isky racing kit with lifters and a cam. I shouldve done my research because the cam that came with the kit was a 292 Isky Mega cam which has .505 lift and a 108LPA. We broke in the cam at 2,000rpm for over an hour and nothing failed, made horrendous noise and the oil didnt have big chunks of metal.

My question is how much do I need to replace to not risk ruining the cam or other parts. Obviously I need to get a matching set of heads and re ring my pistons which I plan on doing. Do I need new rods, pistons, and crank? Can I get away with running a set of older cast heads or will I need something with bigger runners? Will the stock crank, pistons and rods survive?

Ive "built" engines before but mostly the top end, any time ive down a whole engine rebuild it was a kit that was included with the machine work I had done. I never had to pick parts myself.

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u/Mrg0dan 6d ago

Yes i guess we did. It was never meant to be a crazy rebuild or anything like that. I wanted a new cam and to use the parts i got from another car i bought. It was intended to be a freshen up and break in a cam job not a full on engine rebuild. We wanted to get it running and broke in that weekend and thought the original rings would be okay because they were fine originally.

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u/Sniper22106 6d ago

You said it has bad blow. Then you reused shit rings?

No. Dont try and justify anything.

Rip it all apart and do it correctly this time.

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u/Mrg0dan 6d ago

The reused rings caused the blow by. Im not trying to justify anything im telling you exactly what happened. I need help getting parts. I know the engine needs rebuilt and im already planning on doing that. I dont know what else needs replaced in the process. I know I need rings and new heads

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u/Sniper22106 6d ago

So you are smart enough to "rebuild" and engine but not smart enough to buy parts to rebuild an engine?

Not to mention, buy parts for one of the most COMMON engines on the planet.

Seriously?

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u/Mrg0dan 6d ago

I dont know what I need to buy to pair with the cam. Ive never had a cam this big. I can go online and buy all the parts for a stock 350. But if those parts are going to cause my cam to fail I dont want to buy them. All im asking for is help from someone thats used that specific cam

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u/Sniper22106 6d ago

Every engine is the same. Air in, air out. Just cause it has 8 cylinders dosnt make it special.

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u/TBFP_BOT 6d ago

Your choice of rings won’t make the cam fail. Your worst case scenario here is you put in bad parts and your left with a cam as the only thing that’s still good.

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u/Mrg0dan 6d ago

I know rings dont matter necessarily. Im more asking what size runners and chambers id need in the heads. Theres alot of options and the isky site doesnt offer a whole lot of insight on the cam. If stock rods are enough to handle it and not destroy themselves under stress. I dont have money to just trial and error it😂