Hey, i just got my 79 l-82 back from a shop after he looked everything that i did over and got it running right.. on my 50 mile drive home on the highway the vette started to heat up to about 250ish, it seemed that it wanted to heat up more at highway speeds.. when i got home the car was running around 240 and i noticed that the passenger side exhaust was smoking. seemed like the car was burning oil.. It only seems to do this when the car heats up... i bought a new thermostat that opens at 180. and i purchased a mechanical fan to replace the clutch.. is it a possibility that the smoke is due to the engine temps considering that it only smokes when the car reaches excess of 220 degrees, or do you think i have a problem with the rings seating?

 

First off...congrats on getting back on the road with your rebuild. The overheating is the major problem and we will get to that.

If the smoking is from the outside then it's normal when someone is handling the exhaust with greasy hands...it probably smells really bad too. All that smoke and smell should go away in a couple of weeks. If the smoke is coming from the inside of the exhaust then it should go away much quicker...I would have expected a 50 mile drive to have cleaned all the oil from inside of the intake and exhaust...if it persists after another 50 miles then take it back to the shop because it could be a wide range of problems including rings and valve stem seals...I'm assuming that the rebuilder measured the valve stems and ensured a proper fit. The only time a rebuilt engine should spout smoke out of the tailpipe is during the initial startup...it should be clean after just 15 minutes of running at normal operating temps.

Now to what I think is the real problem here...overheating. It's very possible that the heat deformed some valve stem seals...250 is red line for a fresh rebuild just cruising. Did you have the A/C running? Was it smoking at the shop like it is now? Do you have your air dam in place? The fan clutch is there to allow more air to flow through the radiator when the vehicle is moving faster than a solid fan can bring air through...removing the clutch will result in higher temps at freeway speeds and cause the engine to work harder.

I'm hoping that the smoke goes away and you can enjoy your rebuild and stay on the road, but I don't think it will be a pleasant time if you have to deal with a smoking tailpipe...best to fix things up before something serious happens.

 

Sorry i double posted this question not realizing what i was doing.. The engine was built by myself.. As for the heads, they are dart iron eagle 180s. im hoping that it is just a valve stem seal. because i do not feel like tearing the motor apart again.. The cylinder walls were fine when i rebuilt the engine so i only had them honed.. the clutch fan that i was running was shot. it wasn't working the way that i should.. i do not have my scoop on underneath the bumper but before the rebuild i had no cooling problems.. i have an aux fan that i have to wire up and see if that helps.. but the car only smokes after it is hot like that... i really should have done a compression test b4 i posted this, but i am at work an this is on my mind.

 

If it's still smoking then I think the easiest check is the valve stem seals...if they are not seated properly then you should be able to see them. If you didn't measure the valve stem and the valve guide and there happens to be too much of a gap then you might want to think about pulling the heads and replacing the guides. I can't think of any way for oil to get into the combustion chambers unless you have a head gasket leak...so perhaps do a compression test as well as inspect your valve stem seals.

 

Yea im hoping that it is a valve stem seal, but idk.. im going to do a compression test once this heat wave passes over us here in jersey.. The heads were assembled by a factory prior to me purchasing them.. we'll see what happens tho. thanks for the help