Hi guys,
I have 78 with a stock 350. Its been parked for awhile now and I would like to get it up and running again. The main problem was a wall of smoke would come out during start up. After about 10 to 15 min it would clear up. I've been told that it might be oil seeping into my cylinders.Can anyone help.

 

Sounds like bad valve guides. Pretty typical of a smallblock Chevy with some miles on it. Just pull the heads and either replace them, or have them gone through if you like them. I bet new guides and seals will eliminate the problem.

 

Yes, your problem is oil is seeping into the cylinders as it sits. New seals alone might do the trick. Take the car out on the road and bring it up to highway speed. Then get off the throttle completely and let the engine drag the car down till you're going about 30 or so. Then hit the gas hard again and watch behind your car. If you instantly let out a big puff of blue smoke, your valve guides are shot too. By contrast, worn piston rings will make the engine smoke more continuously while the engine is under a load.

 

If you do pull the heads, chech the backside of the intake valves. Oil residue there indicates oil past the guides. Make sure you reinstall the valves with the fat end towards the piston.

 

I've got this same issue with the valve guide seals in my 327. If I shut it off for a few minutes and restart, then no smoke. If I shut it off for a hour or more, then it smokes on start up. It'll get taken care of this winter, so I just live with the little smoke screen for now.