SBC smoking?

[itsals1]

Well this is in my Father's Chevelle. It has the factory 307/powerglide combo has 89,000 original miles. Has Edelbrock carb and intake, flowmaster dual exhaust,no x or cross over. The engine starts and runs/drives good,BUT when you accelerate it smokes out the drivers side tail pipe, to the point That oil is dripping out of the exhaust? The engine does not knock or make any unusual noise at idle or short revs. He had our local mechanic look at it and he's just not sure as it acts like a broken ring,but makes zero noise? I'm not a engine guru so thought I would ask to see if anyone may have some sort of ideas?

Thanks
Travis

[WSSix]

Valve stem seals. Intake leak where it's sucking oil in from the valley. Bad PCV system that's also sucking in oil from the crank case. Head gasket possibly. I doubt it's oil that's coming out of the tail pipe. I would suspect condensate mixed with carbon build up but I could be wrong. Does the engine use oil or anti freeze? Have you pulled spark plugs to see if you can pin point a particular cylinder that's not burning cleanly? What color is the smoke? Does it have a particular smell that's "odd"?

[itsals1]

Thanks for the reply Trey! He has completely rebuilt the PVC system, but we never thought about the intake gasket leaking! Use oil, oh yes, but this just started mid summer 2012. I'm not sure if he has checked the plugs, I do know he just changed them out last spring. It's seems like a blue color smoke and gets worse when you accelerate? At idle its not to bad. I have not noticed any smell but it reminds me of a friends truck in High School, fill the oil check the gas.. Well I hope we can get it sorted out!

Thanks
Travis

[GregWeld]

A good way to tell internal engine health is a Leak Down Test.... and a pro or knowledgable hot rodder can tell by listening - what the possible problem is.

This is a test using compressed air -- and if you listen to the air leaking it can be determined if it's the valves (air leak sound in the carb) -- or the rings (air leak sound in the crankcase) - or whatever...

Using the spark plugs is another good way to get a view of which - if any - cylinders might be a problem.

[WSSix]

The blue smoke says he is burning oil for sure. Leak down tests are great. You can rent or borrow the tool from AutoZone typically. You'd just need a compressed air source. I'd pull spark plugs to see if you can narrow down which cylinder(s) might be burning the oil first and go from there.

[itsals1]

Thanks! We need to check the plugs first, then will we can do the Leek Down Test. I really appreciate the help! I'll let you know how it turns out.

Travis

[GregWeld]

Travis -- Pull the plugs and do the leak down at the same time - since you'll have to thread in the air source where the plug goes. That'll save you some time.

Don't buy plugs until you know what you're up against. If she's an oil burner -- you'll want to get higher heat range for the plugs for sure (more nose extension).

[itsals1]

Thanks Greg,
I hope that its not burning oil as my father wants to keep the 307. I feel bad about the car as I found it for him and ended making the deal on it. Seemed like a real nice car, so just want it not to cost him a small fortune to get his new toy back on the road.
Travis

[WSSix]

Fixing valve stem seals or even valve guides isn't terribly expensive if you can pull the heads off yourself. Intake gaskets aren't hard or expensive to replace either. What I'm saying is don't think that just because the engine burns oil that it's bad or going to be expensive to fix. It could be rather simple really. Do the tests and go from there.

[IMPALA MAN]

I had a neighbor once that chased smoke out of the tail pipe up to and including rebuilding the engine. FINALLY, he narrowed it down to the vaccume modulator on the trans. The diaphragm was broke and allowing trans fluid to be pulled into the intake via a vaccume hose. Easy to check and just thought I'd chime in.