oil passage drilling plug

[Oldhaven]

I noticed a slight oil weep at the bottom of my Rapide timing side crankcase yesterday, and it appeared to come from the small plug at the bottom of the crankcase below the oil pump plug and behind the end of the right side front engine plate. After I removed the plug to seal the threads I noticed that it has a conical point. When I put it back in its drilling it went in about 3/16 inch beyond flush before beginning to tighten up in the threads and felt like it was becoming thread bound rather than seating its point. I stopped at this point even though it felt like I could have continued a bit more. I did not want to strip the threads in the case. My question is whether this plug should be installed tight in its hole or just flush with the outer case surface? I assume this drilling connects in some way with a sump passage in communication with the oil pump and I would not want to obstruct oil return by blocking the passage. By the way, is there a cutaway picture anywhere of the oil circulation passages in this area? That would answer my question.

Ron

 

[greg brillus]

Ron, most ones I have seen seem to be level with the start of the thread. I would say the plug had some form of sealant used from the factory and then punch locked on both sides where the ends of the screw slot is. The conical grub screw was most likely intended for use to lock a bearing to a rotating shaft or similar, and seemed to work ok in this application. I put them in with some good sealant, after a careful cleaning of the screw and the threads up the hole....All good fun whilst trying to look upside down to start the bugger back in the hole. I do not bother punch locking them again, as I rely on the sealant doing this. Give the sealant time to cure before running the machine again, and check for leaks.....Cheers, Greg.

 

[Oldhaven]

Ron, most ones I have seen seem to be level with the start of the thread. I would say the plug had some form of sealant used from the factory and then punch locked on both sides where the ends of the screw slot is. The conical grub screw was most likely intended for use to lock a bearing to a rotating shaft or similar, and seemed to work ok in this application. I put them in with some good sealant, after a careful cleaning of the screw and the threads up the hole....All good fun whilst trying to look upside down to start the bugger back in the hole. I do not bother punch locking them again, as I rely on the sealant doing this. Give the sealant time to cure before running the machine again, and check for leaks.....Cheers, Greg.

Thanks Greg. That makes sense. I will back it out and reinstall to flush after resealing. I looked for this grub screw on the spares list and could not find it, probably indicating it was not considered to be an item meant to ever be disturbed. I asked an experienced Vincent rebuilder with a large ultrasonic cleaner to do a thorough cleaning of the oil passages and reassembly this spring after I found glass beads in the bottom of one of the cylinder stud holes after I had started assembly myself last year. (Luckily, the engine had not been completely assembled or started in the decades since the cases had been cleaned up by someone less careful.)

I still wouldn't mind seeing a cutaway of the oil passages in the crank cases if one exists.

Ron

 

[Pushrod Twin]

Thanks Greg. That makes sense. I will back it out and reinstall to flush after resealing. I looked for this grub screw on the spares list and could not find it, probably indicating it was not considered to be an item meant to ever be disturbed. I asked an experienced Vincent rebuilder with a large ultrasonic cleaner to do a thorough cleaning of the oil passages and reassembly this spring after I found glass beads in the bottom of one of the cylinder stud holes after I had started assembly myself last year. (Luckily, the engine had not been completely assembled or started in the decades since the cases had been cleaned up by someone less careful.)

I still wouldn't mind seeing a cutaway of the oil passages in the crank cases if one exists.

Ron

Item 30, Pg5 The Alternative Spares List 3/8BSW x 3/8long. It is access to the oil pick up/ return line drilling to the pump. Pulled mine a couple of days ago, it was not seated, just relying on the Best Traditional British Punch Lock. Mine will go back with Loctite, maybe 515 gasket flange sealer which self dissolves.

 

[Oldhaven]

Item 30, Pg5 The Alternative Spares List 3/8BSW x 3/8long. It is access to the oil pick up/ return line drilling to the pump. Pulled mine a couple of days ago, it was not seated, just relying on the Best Traditional British Punch Lock. Mine will go back with Loctite, maybe 515 gasket flange sealer which self dissolves.

Good eye! Thanks. Mine stopped weeping with permatex no 2.

Ron