235 six and oil smoke out the tailpipe but good compression?

235 SIX IN MY 61 CHEVY TRUCK IS SMOKING OUT THE TAIL PIPE. CHECKED THE COMPRESSION AND IT IS AROUND 150LBS IN ALL CYLINDERS. I SUSPECT THE VALVE SEALS BECAUSE THE TRUCK SAT FOR A LONG TIME AND IT IS SMOKING THE MORE I DRIVE IT. BUT COULD IT BE ANOTHER PROBLEM? AND IF IT IS THE VALVE SEALS HOW MUCH OF A PAIN IS IT TOO CHANGE THEM AND WHAT SHOULD I EXPECT?

 

Been a long time since I had a Chevy 6 head apart, but I don't recall that they had much of an oil seal on the valve stem. A small "O" ring under the retainer/keeper or something ?

In any case, I think you are on the right track. If the rings and valve seats are good, as the compression figures suggest, oil may well be going past the valve guides, either because of a seal problem or just normal guide wear.

I remember in the 60"s when I work for a Ford dealer, we would have SBF V8 and Inline 6's come in smokin' blue.....change out the valve stem seals, without pulling the head, and Bingo!.....no more smoke. It may be possible to do something similar to your Chev 6.

Smeone more familiar with your engine will likely have additional info to post.

Ray

 

An older engine that sat for a while might have enough sludge to block the oil returning from the head. I'd pull the valve cover to see if it's sludged up. If it is the valve seals, they aren't too difficult to change. It could also be the oil rings on the pistons.

How much oil does it use? Does it foul spark plugs? You could try changing the oil and use a 30 or 40 wt oil.

 

Umbrella style seals are available and work good IMO. Check guide clearance while you're there.

 

Do they offer a umbrella seal my napa store and lmc only shows a o-ring. Is this a retro fit?

 

Does use a good bit of oil but it does not foul the plugs,it runs great otherwise. I thought that maybe the valve seals maybe have cracked and fallen apart from lack of oil and use.

 

Have you adjusted your valves lately?

 

I would think you could use an umbrella seal from "something" that shared the same, or slighty smaller, stem diameter. Just need to make sure there is enough space between the retainer and the guide when the valve is fully open to as not to deform the umbrella.

Ray

 

Rock Auto lists them.

http://www.rockauto.com/catalog/x,carcode,1325337,parttype,5800

You could give your local parts store the sealed power number.

 

What oil are you using?

 

make sure you didn't just overfill the crankcase.

umbrella seals from an SBC will also work.