66 C20 292 Hard start and smoke

[78classic]

I have sold a 66 C20 with a nearly new 292 in it to a friend about 10 years ago. He let it sit around and called me up the other day and wanted to know if I wanted to buy it back...Of course I did. Smoking like a chimney at idle and hard acceleration....didn't do that before? Also I have to prime the carb to get it to start? I imagine the carb is gummed up or fuel pump might be acting up? Most concerned about the smoke...it's oil for sure? What's the best guess? Stuck rings or??? Run the hell out of it and hope it goes away or ????

[chevylookin]

White/blue smoke= burning oil
Black smoke= running rich
First, I would determine if the timing is right. Then Id follow it up with a carb rebuild. If that didnt solve the issue, then its time to start going for deeper analysis like compression tests and head issues like a stuck lifter or a bent pushrod. Also check for vacuum leaks.

[GMDad]

Try some Rislone down the cylinders and let set. Sticky rings I would think once you get the carb cleaned up

[78classic]

Notice it was running rough...missing I guess. Pulled off the valve cover #3 intake valve stuck closed, rocker arm off and push rod barely showing. Pulled off push rod cover. Push rod bent and broke about 2" inches from end. Pulled head drove out valve...it's bent. Off to the head shop it goes. I guess that would cause some problems?

[TJ's Chevy]

Yup....that caused some Severe problems....My hope is that the cam is not flat. How do the cylinder walls look?

[chevylookin]

Sorry to hear about the dreaded diagnosis. But, it coulda been worse. Yeah, like TJ said, check those cylinder walls and do a compression test when you get it back together. Who knows what kinda hot rodding has been done to what that engine was built for. Might as well rebuild the water pump as long as you got her off anyways as well.

[78classic]

Cylinder walls look great still see hone hatch marks. No signs of valve hitting piston. Guess I'll get the head redone and go from there?

[TJ's Chevy]

I'd do a new cam and lifters as well. Right now you chance some cam lobes being flattened.....and you'll find out real fast if you put a good head on there and run it. New cams are cheap, only thing is it would cost more time and you'd have to remove the oil pan to get the timing cover off.....which leads to more work. Guess what I am saying is.....as easy as those engines are to pull....I'd yank it and do a good once over. If the cam looks good then run it and reseal the engine with new gaskets and then the rebuilt head. Makes for more reliability and possibly less heart ache in the future. All depends on your budget and time though....but that's what I would do.