The Stovebolt Site Forums The Shop Area Engine Shop Ring problems

Hope I'm not to long winded,
This is my plite, the 350 in my 68 went out the window. I bought a used 350 from a parts dealer that specializes in 68-72, hired a mechanic from the shop in town to assist in installation of motor,just a swap. However he decided to pull the heads, clean them up and lap the valves. We installed the motor and the truck throws up a smoke screen James Bond would be proud of. I asked the gentleman I bought the motor from about this, he said it did not smoke. He asked what we did and said that by lapping the valves we changed the compression and blew the rings. Another aquaintance of mine said the same thing. My question,is this what happened or did I get shafted on the motor.
Thanks for listening
Mark

Any used engine is a crapshoot. It's possible, but not likely, that working the valves created problems, but that only happens on an engine that's on the verge of failing anyway. Unless things improve with a little driving, your only option is to do what you should have in the first place, and do a full rebuild. The only way I'll consider a used engine is a VERY low mileage one from a recent wreck. If an engine has been stored for over 6 months without some special precautions, it's probable that the cylinders will be rusty, and it will require at least a ring job to be serviceable. For engines I intend to store for longer periods, I drain the oil, and turn them upside down. The remaining oil collects around the rings and the combustion chambers, and prevents cylinder rusting. An engine that's been stored that way smokes like crazy for about a day, then clears up.
Jerry

What about valve seals? when you reassembled the heads did you get new seals in correctly? Sometimes you can put umbrella type seals in. There was a thread on this awhile back. Hot rod knows a lot about this. They can be put on whithout pulling the heads. I,m inclined to believe that is the problem.

how can lapping valves change the compression unless it makes it better than what..??? 0???? from a burnt valve...??? it wont raise the compression and blow rings that arent worn out anyway..??? yeah it may not have smoked before if it was shot or low on compression...??? white smoke is oil...even with rings worn out (compression rings) the oil control rings could still be fair and not smoke, but not smokin dont mean that the motor is good..??? Like Hotrod Lincoln said...its kinda like buyin new socks tho if ur boots are worn out... if theres holes in the soles...socks not gonna last long....LOL....

I think you broke a ring on some rust build-up from the storage. Run a compression test to see if a cylinder is lower than the others. Any way you look at it, it needs to come out is my guess,
Scott

Got your e-mail. What about the pcv valve. If there are no baffles in the valve cover or they are broken oil can be sucked up & into the intake. How about blowby? Does any smoke come out the crankase vents with the pcv valve removed. Pull the plugs & see if oil is getting on some or all of them. Sometimes it is confined to 1 cylinder.

Chevypickmup,

Is there any chance you are seeing anti-freeze smoke instead of burning oil. Looks similar, but dissipates sooner. Run the rig for awhile and see what developes.

Stuart.

It is easy to tell anit-freeze smoke from burning oil smoke---the smell. Anti-freeze smoke smells peppery, pungent, very distinct.