MTFCA Forum

I am working on my 24 Touring and having done a rebuild on engine with a neoprene crank seal, I still see a drip under the front of engine. So I thought to add an additional external seal and want to know if anyone else has done this using an aluminum belt pulley and your technique in doing this. Your thoughts are appreciated!

Personally, I wouldn't worry about it...

The problem with adding an additional seal is that a seal must run with lubricant (that it is retaining). A dry seal will just burn up and be destroyed. From your description, not enough lubricant is making it past your seal to lubricate an additional seal applied on the outside.

T's leak

despite the most super-human attempts otherwise

Hi Harvey,
I have gone to installing a outside seal every time I have a engine apart. The seal I use is a National 471766 because most auto parts
stores have them in stock and they are a relatively thin single lip seal ( so it is shorter ) and they are $6. I cut the outer flange off of
the metal part of the seal so it is even shorter. Clean the pan & timing cover with brake or carb cleaner and silicone it on backwards.
You will probably have to put the pulley in the lathe and remove a little bit from the backside to clear the seal ( I have not had to do
that on steel pulleys ) I like to use the Great Stuff product for this because it can be purchased in a 5 min. cure time but if you use
regular silicone let it sit for 24 hours. I have had good luck with this when a seal ( felt ) failed and oil was running out ( this was
not intended to be a permanent repair) but it did last until the engine was rebuilt years later.
Craig.

Pilot wrote up on maintenance request sheet that engine #2 was leaking oil. Flight mechanic wrote some leakage is needed for proper
lubrication. The next flight the pilot wrote up engines #1, #3 & #4 are not lubricating properly.

The aluminum pulley may need some extra machining on the rear for extra seal clearance.
I have encountered this clearance problem. The original steel pulley has a recessed curved back that gives the needed clearance.

I would never install an engine or radiator without adding a modern oil seal to the outside of the crankshaft! The problem with a small oil drip at the front of the engine is that if you drive your car much that little drip blows back underneath and covers Everything and sooner or later you have a real mess. Montana 500 winner Garrett Green told me about his idea. You do have to install the seal backwards with the lip facing the front and I use Ultra Black or the Right Stuff. Speedy John found some seals that were very thin and most always would have enough clearance. I like one with a large outer diameter. I usually cut stripes in the flange and flatten it out like a daisy flower pedals. Just make sure the surface is clean and you have prefit the seal up nice and tight to the block.
Don't have any problem with wear I guess because just enough oil wicks thru the felt to keep the neoprene happy.