VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Exhaust (White)

1940 Special Deluxe (216) I'm told by others who follow me, that I have excess white color exhaust, in particular when I let up on the gas to slow, It's not enough for me to see in the mirrors, is this a air/fuel mixture problem or oil, it was ringed about 2000 miles ago (11 months. It does use some oil, every 200 miles or so. Any help/suggestions or?

Thanking you in advance.........

How much oil does it use in 200 miles?

:confused: :confused:

It will take about 3/4 of a quart every 200 miles.

I would suspect that the smoke and oil consumption is caused by some oil getting past the valve guides.The 1940 had no type of seal or shedder on the valve stem .Any oil splashed over to the top of the valve spring retainer will pass directly down the guide and be burned in the combustion chamber.In 1941 they installed a metal cap on top of the intakes valve spring retainer to help prevent this.In 1942 they added the cap to the exhaust valves also.In 1948 the used a better retiner for the valve spring and provided an O ring between the retainer and valve stem.
On my 1939 I used a F-O-R-D 302 plastic oil shedder.It slips onto the stem under the retainer cap, moves up and down with the valve and keeps the oil off the stem.Eleminated the smoke (some times noticable on start up also) and cut oil consumption to 1 Qt. in 2000 miles.
To install them an air fitting is inserted into the spark plug opening to hold the valves "up".with a on-car spring compressor the spring can be compressed, retainer remover,shedder installed and parts reassembled.

3/4 of a quart in 200 miles is bit excessive. What type of rings did you install....cast iron or chrome?

I had the rings, rod bearings and valves done by a local engine shop, which I would not use again or recommend for vintage vehicles, anyway the reciept says they are steel, I would assume then cast iron.

Yep......there is one rule that we all learn in this hobby sooner or later, and that is you never take your vintage engine to a local machine shop. :( :( :(

Since your oil consumption is extreme it sounds like Chev Nut's diagnosis is right on.

A compression test would help check ring sealing problems as a possible cause.

I ran a compression test as follows:
1- 70
2- 68
3- 68
4- 65
5- 76
6- 76

Those readings appear low, was that a wet and dry test or just a dry test. If dry only run a dry and then repeat with a wet test. This would help determine if the rings are seating. JYD, your comment on using a local shop is probably more correct than not but there are local shops that have some real machinists working and can and do good work on older engines.

glyn: True, but I guess that it all depends upon where you live. However, when it comes to poured babbit engines many of us have found that most local machine shops don't have a clue as to what they are doing, and they usually do more damage than good.

:( :( :(

Bill - I have a 1940 Motors manuel that sez 90# at cranking speed is the minimum you should have on a 216. Since all of cylinders are so close in compression range I would think that it is the rings. If you want, give me a call. I had something comparable happen on engine recently.

I would try a different compression gauge.Was test made with all plugs removed and engine cranking at a normal speed?(normal with plugs removed would be faster than with plugs installed)...compression should be in the 110 pound range.If rings were "leaking" that much there would be a lot of blow-by.("some" is normal)

Gene,
Wouldn't you expect to get some light gray smoke if the rings were leaking particularly when you let off the gas? And then larger puff when you hit that gas again?

Sure seems that a dry and wet compression test is in order. Run all cylinders dry with all plugs out. They repeat with a large squirt of oil in each cylinder. When the readings are compared for each cylinder it will give a good indication of the leakage past the rings. Alternately you can do a leak-down test. It is better but takes more time and equipment and normally not worth the extra effort.

Before I installed the shedders on my '39 it would leave out a puff of smoke when letting off on the gas and hitting it again such as when shifting...I wouldn't have know this but let a membr use the car for a tour and I was following it.Also smoked a little on start up and when backing off at higher speed (higher vacuum sucking oil past the guides?0 and this was with new guides.

I would agree that if the compression readings are accurate a leak down test would be in order...Or at least a wet and dry test.I would think that the compression rigs would be seated in 2000 miles if the bore was round.

Just my two cents, and since we know the engine may have low compression and possibly other issues the oil consumption is probably correct, especially given the showing on deceleration. However, if the coolant system is antifreeze wouldn't antifreeze burning the combustion chambers produce an unusually white exhaust? Jim Leman

If the coolant was leaking into the cyliners in a great enough rate to produce noticeable white smoke (from the water not the antifreeze) then the cylinder(s) will fill with water on standing and hydraulically lock the cylinder(s). Besides the ethylene glycol is easily burned producing no smoke. Water produces steam or "white smoke". Burning oil typically produces a light grey smoke which many call white.

WHMarquis
If it was burning that much oil I would expect it to blow blue smoke (blue is oil, white is coolant and black is excess fuel). If coolant is getting into combustion chamber I would expect bubbles in the radiator unless there is a crack in the head between water jacket and a port, in your case with fairly even compressions the latter is more likely.
I would also check valve clearances as a cause of low compression. While doing clearances open valve slightly and try to move top of stem sideways (should be no noticeable movement), this will give an indication of valve guide wear.
Tony