[Healeys] Oil Leak

[john spaur]

Bob,

If you installed the square cork with sufficient gasket sealer I 
doubt it is the source because, I would think there would be oil on 
the rear plate outside of the bellhousing because the cork is 
sandwiched in-between the plate and the rear main bearing cap. It 
could be flowing over the top of the cork into the bellhousing if the 
plate was cut too low but I think that would be unlikely too but the 
design of the notch in the rear cap would make that hard too if there 
is sufficient gasket sealer. I had this issue on my rear plate but it 
never leaked until I fixed the rear plate to eliminate that potential 
problem. I should have left well enough alone because I suspect my 
rear plate is warped now.

I have a similar leak and it is coming from the rear plate through 
the hole for the crank due to a failed gasket between the block and 
plate. At least that is what I had previously and I suspect it 
reoccurred. However, it does not always make it to the cotter pin 
because it can leak between the plate and bellhousing. Oil can also 
blow back from other sources and be hard to trace because there is so 
little oil. Blow back oil usually follows a seam (but not always), 
such as the one between the valve cover and head, the tappet cover 
plates or from the back of the valve cover down the back of the head 
and then down along the seam between the mounting plate and engine 
block. I found one coming from the oil feed pipe on the distributor. 
All of these leaks will find their way to the lowest point on the 
engine which is the bottom of the bellhousing/ mounting plate.

Clean everything off as completely as you can, especially the seams. 
Run the engine up to temperature and let it run until you see the 
leak again. Then take a clean paper towel and start wiping the seams 
and follow the oil path. There is also a cheap leak tracer kit you 
can buy. A small amount of a chemical tracer is added to the oil. 
After the leak is apparent a light pen (comes with the kit) is used 
to make the oil fluoresce. You can't see the trace chemical without 
the special light source. Harbor freight or Oreilly's might have the 
kit. I have the light pen but not the chemical.

John

At 03:17 PM 3/3/2013 +0000, you wrote:
>Yeah, I know...
>
>Any ideas? Could the seam between the rear main bearing cap and 
>block--with the undersized felt, cigarette-shaped plugs on either 
>side--be the cause? We get a few drops on the floor after a 4-5 mile run.
>
>TIA,
>Bob