AB the only source for rear main oil seal?

[DJK]

On 12/5/2023 at 8:42 PM, Sniper said:

 

As I stated and you failed to understand, what people, aside from you, are calling a rope seal fits into a groove that is machined in the block and rear main cap.  What you have is a bolt on seal that does not fit into a groove machined into the block and cap.  The actual sealing material composition is irrelevant to the popular nomenclature.  You can call a duck a goose but no one is going to jump.

My 52 has the rope seal that fits into a retainer as shown, my 53 engine has a neoprene seal that attaches as shown in picture.

[James_Douglas]

I have commented on this before, but I have had terrible luck with the Best Neoprene Seals. On my '47 with a NOS crankshaft that was balanced and polished I have had several of their seals leak.

 

If you look in the archives I posted photos of the best seal and a NORS Victor seal. The differences are obvious. The Victor seal has a much larger contact area on the shaft then the Best version. Also they had a vulcanized fabric on the seal surface as well.

 

I also contacted Best and asked for the Engineering specification as to the allowed shaft minimum size and maximum size for their seal. They would not provide one. I suspect that my crankshaft my be too big for their seal specification and as soon as it turns the mico-lip gets destroyed. But without specification to check what the shaft ID-OD tolerance is for the seal there is no way to know.

 

Now I resurrected an engine some years ago that was rebuilt in 1964 by Automotive Engineering and then got parked in 1965 and did not fire off for decades. I cleaned the pan and ran the engine. The rear main is sealed very well, better than most. The seal is rope.

 

I think that the Best Seal has too small a contact point on the crankshaft. If there is any undue stress back there (shaft movement) or any contaminates get in there that thin micro-lip get damaged in a split second and then never will seal right. Micro Lip modern seal are great on modern engines with their close tolerances, but on older cars I wonder.

 

As an aside a lot of people who race old XKE's found out the hard way that modern seals just do not work on XKE inboard disc brake axle seals. The things get too hot and the seal die and oil dumps out. The old leather seals take the heat and have a larger contact area. Just like the pinion seals in our cars. I use NOS or NORS pinion seals if the leather is still good or modern leather if I can get them on my Desoto's.

 

In the future all of my engines will get rope rear main seals, and on the blocks that have the bolt on back plate style neoprene seal, I may use both.

 

James

 

 

 

 

Edited December 17, 2023 by James_Douglas

[Plymouthy Adams]

if you have a question on the size of the seal verse the size of the shaft it rides on, what measurement did you arrive at and based on the tolerance of seal to shaft in most machining handbook, you should quickly arrive at your answer.  

[DJK]

On 12/9/2023 at 8:30 PM, DJK said:

My 52 has the rope seal that fits into a retainer as shown, my 53 engine has a neoprene seal that attaches as shown in picture.

[DJK]

2 minutes ago, DJK said:

Edited December 18, 2023 by DJK