I just got my car back from the shop. I took it for a tune-up but they told me a tune-up wouldn't help it. They took compression of just first 2 cylinders and got 90 and 100. The engine (350) runs average, but when i hit 5th gear (tranny swap) or above 55 mph or just lay into it the engine backfires like crazy! The shop told me i have a "tired" engine and need a new one. What can i do other than completely rebuilding or buying a new one?

I would,recheck timing and carb. setting's.Set for total timing 32-38 I think it was :rolleyes: .Do you have a timing light?Or maybe you could borrow one,from someone.

Does it smoke any out of exhaust?

Do a seach in Engine forum,timing and what ever carb. your running.

Hope fully someone else will chime in here to help ya smile.gif

Is it backfiring out the carb or tailpipe or both?

With 90/100 PSI compression, (assuming they did it right) I'd say the engine is pretty tired. If you are not blowing a huge cloud of smoke, the wear probably centered more on your valves. Tired old springs maybe letting them float a little or not sealing properly and letting the exhaust valve burn.

If you timing/carb checks out, and you think the problem is centered in the heads, you may rebuild them and see if that helps a little. or pop on a set of salvage yard heads. But it doesn't sound like the engine has too long to live.

Good Luck, though!

Yes it is back firing out of the tailpipe, and it also blows grey smoke. Im not too sure about the timing though. I guess its just an old engine. the carb is an edelbrock 600

I think it's burnt exhuast valve/s.

Do you hear any ticks? if so, check the heads, make sure there isnt any studs coming out(if they are the pressed in ones)or lifters that may have collapsed. b/c My chevelle had this problem and each time I floored it, it would bang and boom like crazy, just my $.02 graemlins/clonk.gif

What do i do if it is burnt exhaust valves? Also the left tail pipe blows warm, but the right blows cool, with what appears to be water (doesn't smell like gas).

look at camshaft it may be going flat had this many times in my shop