I recently converted a auto 351W for marine use, reverse rotation. Everything went well until I got to the rear main seal and saw the oil groving done just ahead of the seal to promote oil removal in front of the seal.

I installed a "speedy sleeve" and went ahead and installed the standard 2 piece rubber seal. This seal failed within a short time. Tear down showed that part of the seal had transfered itself on to the journal, and the remaining lip of the seal was roughened up.

A second rubber seal was installed, with extra lubrication, thinking that the first seal ran dry. It too failed in a short time.

I am considering using the old style rope seal-

Question- is this seal still available and would you recommend it as a cure? I can handle a few drips-but not the deluge I am getting now.

Thanks

Dave, with way too much oil in the bilge.

 

The knurling on the reverse crank is running the oil into the seal on your std rotation, I don't think the rope seal will help in that case. The knurling shouldn't be contacting the seal period, even if the crank's turning backwards of what it was designed to do.

 

I have installed a speedy sleeve that covers the knurling. I believe that the increased diameter is causing too tight of fit with the rubber seals- thus the reason to try a rope seal. Speedy sleeves are about the thickness of a beer can, made out of stainless.

The marine application is double tuff, as on bringing the boat up on plane, the engine angle gets ugly.

Shuffster

 

In that case, I'd try and remove the knurling and leave the speedy sleeve off and use the rope by itself, if you can get one. If not get a std rotation crank. With the stroker kits out there now, the stock stroke cranks should be cheaper than you'd expect.

 

Let me clarify: This engine was an auto engine. It is now a marine engine, running opposite rotation. I did find reverse rotation cranks thru NAPA, but I will only do this change as a last resort. Thanks for the suggestions.

 

Ok, I see. Same difference though just the crank's are harder to come by.

 

what is the difference in them.......

 

simply the frets or grooving applied just north of the rear main seal.

 

The knurling just forward of the seal surface that guides the oil excess away is reversed. I've only seen one of these pieces and the machinist that had it pointed that out to me. Otherwise I think it's the same casting unless the oil passages are also reversed.

 

May be that the speedy sleve is starving the lip seal somehow. I think if it wasn't so much trouble to try it, That may work. All that would happen is lots of oil will be directed at the new seal and it still should drain away before it blows out the seal.
Good luck whatever you do.

 

Thanks DaveBB for the encouragement.

I will be pulling the engine in a few days to examine seal area.

 

You need to either run the correct crankshaft or speedi sleeve it and run the correct reverse rotation rubber lipped seal. (the little grooves are reverse cut on the actual seal lip) The only problem with the rubber seal is that it is not available for all engines, so you may be forced into installing the correct reverse rotation crank.

There is no other work around that will last.

I have 33+ years of training and experience in the pleasure boat as well as light duty commercial marine fields, and I wish I had better advice.

I would also advise that if this is a automotive engine, you pull the heads and have the sodium filled exhaust valves installed, if not already installed. Otherwise your exhaust valve life may not be up to your expectations either.

Good luck, David

 

I believe the reverse rotation engine takes a different seal. And the speedy sleeve Makes no difference. Like dmanlyr said. I also have around 30 years in marine inboards. The standard seal isn't letting oil to it. It's not the sleeve. But I do sleeve a standard crank when reversing. JMHO

 

Arctic Y Block/ Dmanlyr - I actually used the reverse rotation seal on the first round and it left a rubber trail around the sleeve. I used a std. Rotation seal on the second try and it is leaking. I need to tear it down to examine and see what happened to it. Perhaps I didn't get a good pan seal this last time. Obviously as the boat goes on plane, there is significant oil to the rear.

By the way, the engine is in a old Century Resorter, seldom sees much load, mostly taken out for Cocktail cruises on Payette Lake, McCall, Idaho.

Do you know if rope seals are available for early 351 W ? I may wind up ordering a new crank for next year, but would like to make one last try now to enjoy the boat for a couple of months.

Thanks

 

I don't know on the rope seal. Maybe try to find one close like maybe for an old Y or FE. and cut its length down to fit. Be sure ta presoak it.