Chevrolet 216 rope seal? Yes or No?

[Alex van de Wetering]

I am looking for some opinions on the rope seal on the rear main bearing cap on a Chevrolet 216.

I have my engine parts back from the rebuilders and they are patiently waiting for me to find the time and energy to put everything together. It took out a fair chunk of my budget, but now a friend told me last week that I should also consider having the rear bearing cap machined to take a modern day seal.

Who out there is using an original style rope seal (one of the non asbestos replacements) with modern day oils? Any trouble?

Alex

[Mike Kelly]

Alex

The rope is fine if installed correctly. No problem

Apply some grease on the rope to prevent burning during first start up

[Phil Waterman]

Hi Alex

This family of engines all seem to leak oil, if not at first then with time and miles. I have continued to use the rope type seals with reasonable to good results. Once I rebuild an engine I do go over using detergent oils. Rear main rope seal seems to work fine without leaking, but these engines engines from many different locations collective do leak more than modern engines.

As Mike points lubricating the seal before installing is important. I've always soaked them in motor oil for several days before installing.

The bigger issue I've seen is the condition of the bearing surface it needs to perfect. If the crank seal surface has any imperfections have it resurfaced/ground, or use a speedisleeve. I have had very good luck with this approach.

Would offer another comment that these engines need to run regularly and I mean driven for an hour plus. My HUP still had its original seal in 2011 I had been driving since 1978. It would leak from the rear main each spring until it had been given a good long drive.

Long winded way of saying use the rope seal fine just get out there and drive it regularly.

Cheers Phil

[Richard Farrant]

Back in the 1970's/80's I rebuilt countless Bedford six cylinder engines for the UK armed services. They were a derived from GM engines and the 300 petrol annd 330 diesel engines still used rope seals in rear mains right up until Bedford trucks ceased production which I think was around 1989. The seals were impregnated with graphite and we had a dolly to form the seal in to the block and cap, then trim it off. The rubbing surface of the seal was net smeared with a graphite paste to aid it on first start up. Never gave much problems unless mains were worn then it took the pressure off the seal.

Phil, I can't see how you could fit a Speedisleeve to a crank as usually the flywheel flange is larger than the seal path.

regards Richard

[Phil Waterman]

Originally Posted by Richard Farrant

Phil, I can't see how you could fit a Speedisleeve to a crank as usually the flywheel flange is larger than the seal path.

Hi Richard

You are thinking of the rear main bearing face, which you are correct can not be sleeved. Take look at the two photos, I'll try and get the Speedi-sleeve part number think I have it out in the shop.

Pretty simple to drive the sleeve on with the tool provided then you break off the and peal off the drive flange.


Also have include picture of sleeve for the other end. Going with speedi-sleeves is a good fix if the engine is not be fully rebuilt.






Cheers Phil

[Richard Farrant]

Originally Posted by Phil Waterman

You are thinking of the rear main bearing face, which you are correct can not be sleeved. Take look at the two photos, I'll try and get the Speedi-sleeve part number think I have it out in the shop.

Hi Phil,
Ah, I see the Chev seals on the flange. Most engines I have rebuilt which had rope seals sealed on a journal inboard of the flywheel flange so impossible to use a speedisleeve. I have used them on gearbox drive flanges and are very good.

regards,
Richard

[Alex van de Wetering]

Mike, Phil, Richard,

Thanks so much for sharing your thoughts and experiences with the rope seals; very much appreciated.
I will proceed with the rope seal and be sure to soak it in oil and/or give it a coat of grease when assembling.

thanks guys,
Alex