Rope Seal vs. Neoprene

[Jerryl]

Understand "new technology" is available but let's discuss assuming properly installed and working rope seal.

-The purpose of the seal is to prevent oil leakage and keep dirt from entering.
-Oil leakage chances increase when crank case pressure starts to climb.
-99% of crank case pressure is primarily due to ring seal (no PCV installed).
-If crank case psi is reduced with breathers, why would a rope seal not work?

Yes, neoprene seals are simpler, cheaper and easier, but that doesn't make rope seals less effective. Thoughts?

 

[Turbo6inKY]

Understand "new technology" is available but let's discuss assuming properly installed and working rope seal.

-The purpose of the seal is to prevent oil leakage and keep dirt from entering.
-Oil leakage chances increase when crank case pressure starts to climb.
-99% of crank case pressure is primarily due to ring seal (no PCV installed).
-If crank case psi is reduced with breathers, why would a rope seal not work?

Yes, neoprene seals are simpler, cheaper and easier, but that doesn't make rope seals less effective. Thoughts?

You answered your own question: Neoprene is simpler, cheaper, and easier. Doesn't matter whether or not rope will or will not seal as well, they're a pain in the butt and there's no reason to use them anymore if a neoprene seal is available.

 

[robertf]

With Neoprene seal ease of use and availablity, I'm surprised rope seals are even still available.

 

[ek02]

Rope seals can really only be properly installed with the crank out of the engine, and the use of a half moon shaped factory tool to drive the rope seal evenly into the block and cap. That's all we used when I was a Ford heavy line tech back in the 60's and early 70's. We used Chinese fingers when done in the car, and they always leaked a little, but usually less than when the car came in. The neoprene seals were the greatest thing for in car replacement when they came out.

 

[BEATAV8]

Man I hate rope seals

 

[Nigel]

Only thing I can add is that the neoprene has a significantly less chance of ending up in the oil pick up.

 

[turbobitt]

There are some important points to consider,
1 - Cranks with a knurl are designed for the rope seal. An I may be mistaken but I believe need a certain amount of seepage to keep the rope from burning out and is probably the function of the knurl, to control oil lube to the rope.
2 - Installing a new neoprene seal on a knurled crank will probably give mixed results, given the condition of the knurl. This doesn't mean it won't work..... There have been instances where the knurl was to aggressive and has chewed up rubber seals.
3 - Neoprene,Flouroelastomer seals seem to work best on smooth surfaces.
AG.

 

[Jerryl]

Does anyone have the pn for rope seal retainer ring, or have a new one for sale?

 

[robertf]

There are some important points to consider,
1 - Cranks with a knurl are designed for the rope seal. An I may be mistaken but I believe need a certain amount of seepage to keep the rope from burning out and is probably the function of the knurl, to control oil lube to the rope.
2 - Installing a new neoprene seal on a knurled crank will probably give mixed results, given the condition of the knurl. This doesn't mean it won't work..... There have been instances where the knurl was to aggressive and has chewed up rubber seals.
3 - Neoprene,Flouroelastomer seals seem to work best on smooth surfaces.
AG.

Number 2 maybe why some neoprene seal tend to leak a tad down the road after an install.

 

[turbobitt]

Another Item I forgot to add to my list,
1 - Cranks with a knurl are designed for the rope seal. An I may be mistaken but I believe need a certain amount of seepage to keep the rope from burning out and is probably the function of the knurl, to control oil lube to the rope.
2 - Installing a new neoprene seal on a knurled crank will probably give mixed results, given the condition of the knurl. This doesn't mean it won't work..... There have been instances where the knurl was to aggressive and has chewed up rubber seals.
3 - Neoprene,Flouroelastomer seals seem to work best on smooth surfaces.
4 - Lateral cap alignment is critical since you are now relying on a smaller pinpoint sealing surface and they now need to be in near perfect alignment. The rope seal is very wide and forgiving.
AG.

 

[earlbrown]

Interesting thing about rope seals having to leak....

Back when I had time to build timing covers the first thing I had to do was knock out the factory rope seal retainer and seal. Needless to say I ended up with a BUNCH of them......


Fast forward to when I rebuilt the jet in my BBC jetboat. The Berkeley jet uses 5 rope seals around the shaft to seal out lake water. (part #24). It has a clamp that adjusts the compression to squish the 5 rings against each other and squeese the shaft firmly (giggidy) #7. When done correctly you get right at one drop of water per second entering the boat. If you don't leak, the seals get smoked with a quickness.

Also, there's a rubber lip seal (#26) to keep water SEALED off from the very important thrust bearing #32.

Moral of the story, lip seal, good... rope seal, leaks.





And after typing that I recalled a guy with a lathe make a UHMW sleeve that used plain ole rubber orings to seal the shaft to the housing.


It's almost like rubber works better than a rope packing gland.