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I just got a stock 70 351 Cleveland running after sitting 30 years. Motor was tight from sitting, so I lubricated the cylinders with ATF and she came free with the starter not from hand cranking. New gas and tank. Good carb. New timing chain. Car idles perfectly and runs strong. Running the vacuum gauge reads solid at 20. Oil pressure is good on the dash gauge and I have not taken a mechanical reading yet, but no clacking or knocks. Runs, drives perfectly; just smokes like a 1976 KISS concert after she warms up a few minutes and seems to then smoke no stop from idle to the worst at mash the gas. She burned through 2 quarts of oil in 2 hour driving/idling around the hood--not good. I've never had a smoker like this and I know worn/broken/stuck rings or worn valve guides/seals are the first place to look. I have not pulled a valve cover yet, but the oil pan had sludge only, no valve seal material from the heads above. Maybe the head oil drains are clogged with valve seal material, so I will pull a valve cover soon. Motor appears never apart. Has about 100K miles. Smokes from both exhaust pipes. But cranckcase blow-by is very reasonable.

Are there any Cleveland lovers out there that know something I don't about these canted valve motors that might make a smoker? Thanks!
 

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It's probably just the valve seals. Maybe the guides.
After 30 years of sitting, those seals are probably toast. Though I admire your optimism in firing it up.

Pull a cover and see what is happening. Read the plugs first, if you're squeamish about it and that'll tell you if it's just one bank or both that are causing the problem.
A little oil goes a long way.
 

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To me, this sounds like goop or seal material clogging the return holes in the heads, oil fills up and goes right down the guides.
 

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It could be a number of things, but I am thinking maybe a few. Valve seals are definately trash after all that time. Also it is likely that the rings lost their seat and wont reseat if it was siezed up like that. There has to be some cylinder wall damage from being stuck in the same position for 30 years. I say at very least pull the heads and check it out. Would be a good idea to replace all the gaskets anyway.
 
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