I've got a Chevy 230 engine that has been smoking for a little while now, mostly on deceleration and changing gears. I decided to change the valve stem seals in attempt to stop it but i just took it for its first test run and it still smokes a little but but not as much, and it smokes a pretty good bit when I rev it up when I'm stopped and out of gear. I understand that I need to do a compression check but I haven't had the chance to because I have the wrong fitting for the gauge. I know the rings have the highest probable cause but I was wondering if there was anything else it could be or if there was anything else I could try to clear it up. And I don't know if this would have any thing to do with it but it's also hard to start when I crank it up, almost like it's got very high compression... It seems to turn over easier when I hold the gas pedal down. Posted using the Full Custom H.A.M.B. App!
Why can't it smoke, it's old enough ha ha ha. Drive it some more, there could be a buildup of oil in the muffler that has to burn off. If you go for a 50 mile trip maybe it will stop smoking. The symptom you describe matches valve stem seals, which you say did a partial fix. A compression test (wet and dry) will tell you how the rings and valves are. A quick test is to remove the oil fill cap with the engine idling and cover the hole with your hand. There should be a very slight suction on a good engine. If there is a lot of air blowing out, the rings are bad causing blowby.
Rings and valve guides/seals are about it on that engine when it comes to oil getting into the combustion chamber and burning. I'm not sure how well versed you are in running a compression test but the correct way is to pull all of the plugs and prop the throttle plate wide open to give you a proper reading. My old auto shop teacher taught me to let it hit 5 times on each cylinder and run all of the cylinders before going back and running the wet test if a wet test is needed. I'd also hook up a vacuum gauge to the engine and after seeing what it is doing compare that to the vacuum gauge reading page that is in most shop manuals or can be easily found on line. That can tell you what shape the valve guides are in.
When I pulled the valve springs off I wiggled the stem around to see if there was any type of play in the valve guide and they all seemed pretty tight. I also compressed the cylinder with air using an old compressor Chuck screwed into an old spark plugs threads and it worked great. I also couldn't really hear any leaking down inside the block like the rings were bypassing air. I guess I really won't know until I do a wet and dry comp test. I'm praying that it's just old oil built up in the manifold haha. Thanks for the info though guys, I'm gonna try to rig up the air Chuck thing I made to work with my compression gauge and I'll see what I'm with. Posted using the Full Custom H.A.M.B. App!
When you were replacing the seals did you check the guides for ware? In the late 60s I'd replace new style chevy 6 guides in 4 or 5 heads a week.
try putting 1/2 cup of rislone in each cylinder & let it soak for a week, then spin the engine over with plugs out then replace plugs, start it & let it run for an hour or so & then drive it for a while it will smoke quite a bit but will clear up u could have a couple stuck rings. I have done this many times with good results
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