VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 1931 Chevy 194 Engine Problems

My 1931 Chevrolet has the original 194 CID engine in it and has been running great up until now. It has started to smoke and appears to be oil burning. I pulled the plugs and they are dry. The compression is the same in all 6 cylinders and it seems to start and run fine. I am thinking valve seals but could use some opinions as to what to check or replace first. The engine was completely apart two years ago or about 350 miles ago. All of the gaskets were replaced including the head gasket at that time.

The first Chevrolet to have valve seals as factory equipment was 1948. In 1931 the oil was free to run between the valve cap/valve stem and down to the guides. Normally it causes no problem. Excess oil going down the guides will usually foul the plugs. Some rebuilders do install some type of seal but they are not necessary.
Is it black rich mixture smoke or blue oil smoke....or white coolant smoke/steam?
At less than 400 miles the rings may not be seated.May take another 500 miles.

could be coolant being sucked into the cylinders, I'd check the snugness of the head bolts. if it's had a lot of heat cycles it won't hurt

Thanks for the info. It appears to be blue oil smoke. When the engine was apart the cylinders looked good so the pistens were not removed and the rings were not replaced. The problem started at the end of the driving season for us northerners last year and has continued to get worse this summer. I torqued the head bolts to specs when I assembled the engine but could they need retorqued? The plugs look dry and are new.

I would say the "rings were not replaced" is the problem.

I agree with Chev Nut. And, the cylinder bore may be worn beyond specs. as well.

:) :grin:

Thanks for the info.. The cylinder walls measured within specs with the piston down and the cylinder walls were smooth with no ridge at top of cylinder. Wouldn't the compression be lower on the bad cylinder? They are all at 60+ pounds. I noticed tonight that the smoke is more gray than white or blue and there seems to be alot of moisture in the exhaust system. There is actually water dripping from the tail pipe when it is running.

Until the exhaust system has reached operating temperature water can come out of the tail pipe. Some water condenses as the system cools from the last time it was run. Other water is produced in the combustion process. So some water is not a problem.

Now if water continues to come out after the tail pipe is hot and the smoke is white or gray likely coolant water is leaking into the combustion chambers. See the '29 heating problems being discussed on forum in this category for more information on that aspect.

Thanks for all the info,.I am going to check the torque on the head bolts Saturday and see if they are still at 75 pounds. I am kinda hoping that they aren't since that would be a easly fix if all I need to do is retorque to solve my problem. As a second question, have any of you with this year and model had any vapor lock problems. Would this problem be at all related to the problem that I am having since the engine quiting for no reason and then starting after sitting for awhile and the smoking both started at about the same time.

i would think that 75 #is a bitt excesive on the early head bolts could stretch i use about 60 - 65 and that may be a little excesive

50 to 60 pounds is safer on the original head bolts.

:) :grin:

You mentioned smoke out the tailpipe but I did not see any mention of smoke out the breather pipe or valve cover vents.If the rings are worn excessively and compression is leaking by you should also notice smoke from both of the above,if not I think the problem would be cylinder head gasket related.

Thanks for the info, There isn't any smoke from either the breather pipe or the valve cover vents. It is just from the tail pipe and is gray in color. It seems to have good power on acceleration and the smoke is more noticable at idle or at a slight increase of engine speed but maybe that is because you are not moving. Once you start going down the road it seem very slight but is still there.