Crankshaft rope seal , what material is best ?

[carfanatic]

Hello all ,

1932 engine , what is the most suitable material for crankshaft rope seal ?  The groove in the block & rear mains cap is 5mm wide , although  metal shim strips will be needed under the seal.

 

Am in UK.

 

A seal supplier on ebay has 3 types of 5mm square rope seal ;

 

1) Pure PTFE fiber with PTFE & silicone lube

2) Aramid fiber with heavy PTFE lube

3) Pure graphite yarn

 

Thanks for any advice.

 

[Akstraw]

I think that PTFE and aramid are rather robust materials, and would cause the metal shaft to wear faster than would graphite.

[carfanatic]

2 hours ago, Akstraw said:

I think that PTFE and aramid are rather robust materials, and would cause the metal shaft to wear faster than would graphite.

Thanks for that interesting observation , I was thinking that pure graphite yarn might be a bit soft & a bit more like what one would use in water pump packing where the material is in a more confined space.

[paulrhd29nz]

Been using the strands from the old style cotton floor mop. On the hudson F head you drift the material up with a punch until refusal. Never any leaks. 
Got the advice from a very long time hudson mechanic. 

[nickelroadster]

The graphite yarn would be more like what it originally had.  The PTFE will start to wear your crankshaft.

[PONTIAC1953]

old pontiac engines that i have rebuilt use a graphite rope seal, not square but round.

[richwill262]

The PTFE will start to wear your crankshaft.