E: Engine Vincent pilgrim pump in comparison

[clevtrev]

Classic Biker shows a drawing and a picture of the inside crank /case which is from my engine. On my first trip on the bike six weeks ago of 50 miles, I had done about forty miles and stoped to pick a puller up from a mate and as I stopped leaving the engine running picked up the parcel and returning to the bike noticed the oil pumping out of my filler cap taking the usual path of between oil & petrol tanks cascading down over the engine onto the ground. Nocking up neighbours to get news papers to wipe up the mess and soak up what I could from the neck of the oil tank.
Question:; why after forty miles or so did it suddenly spew forth so much oil ? The only conclusion I can come up with is that the weir stand pipe where the inlet is just behind the end face has come out of location and then emptied the reserve oil gallery. But I'm still getting my usual oil pressure to my cam oil gallery of 1 bar or 15psi . Does one consider that the auxiliary oil pump suction is lower than the scavenge suction of the main pump. D/4 is what I recall doing as this is equivalent to full bore area around the base bearing in mind that the c/case thickens towards the out side edge and it seems a slight rise at the curve of the casting.
Do I strip the motor for the 8th time since having it in 1964 or leave it be as the stand pipe isn't going any where !
STRI OR LEAVE.
bananaman

Question is, did you use the left hand prop stand ? because if you did, the scavange hole would be high above the oil level, therefore the sump would have a tendency to overfill.

 

[Marcus Bowden]

Gents after my last quick strip down to just fit new mains six days I damaged my oil pump bronze sleeve and ended up fitting a mismatched pump assembly that sumped in les than a week, so I fitted a cock on my oil tank outlet with a linked rod to my petrol tap, But like I said had done about forty miles by which time the sump had it been flooded would not have had excess oil in by then, when it decided to dump a good cup full of oil !!!! Yes I did use the LH side stand Trevor which would momentarily reduce return oil as the scavenge suction is on the RH side. Next day I used it again up to Plymouth and back with out trouble and nothing untoward still having oil pressure to my cams !

 

[vibrac]

I have mused on this and cannot see anyway this occured implicating your Honda sub system as it only circulates oil fed by the main system in and out of your tank. Either the total amount of oil exceeded the capacity of your tank or the feed to the engine was blocked. A lack of oil in the tank could be ascribed to the Honda pump by I would have thought a minor degree at most.That it happened at tickover is a further puzzle unless the LH lean affected the stop valve on the feed pipe (how I can't see)

 

[timetraveller]

I don't think this works either. Marcus is a very experienced Vincent rider and when he started the run his oil tank would not have been overfilled, or, one would assume, not even filled to the lower end of the oil filler tube. Consider that the oil tank contained, let us say, three pints and that there was a further one pint lurking inside various parts of the engine (the filter housing holding most of that), then no matter what happened to various pick up points there cannot be enough oil in the system to over fill the tank. Remember that Marcus had already covered 50 miles. If that is accepted than my guess is that air must have been being fed into the oil and aerating it to the extent that it foamed and increased the volume. Once again I do not see how the oiling system can do that but neither can oil be created from nothing. ( I am assuming that Marcus does not have some arrangement with Cornish fairies to produce oil for him in exchange for a glass of milk at night.)

 

[Marcus Bowden]

I just think the weir tube has come unstuck (fallen over) so the reserve of oil in the catchment area behind the flywheel has suddenly been taken up by the main scavenge pump and over flowed my oil tank. But as I'm still getting my cam oil pressure I'm not unduly worried just trying to work out why aloud, so thank you gents for your inputs, all very interesting.
Bloody great this forum, not even made to feel like an idiot.

 

[timetraveller]

Hi Marcus, if that is right then does that mean that one does not need to have the weir tube for that mod? If so then it would be one less thing to go wrong.

 

[greg brillus]

Can i ask if the tank breather (chain oiler to some folk) has been blanked off..........?

 

[Peter Holmes]

Sounds to me like you might have discovered an uncapped oil source, time to call Red Adair.

 

[Marcus Bowden]

Norman my handsome, you are correct but carful measuring must be done to ensure that Honda p/p suction pipe is lower than the main scavenge port.
Greg my handsome, the breather / old chain oiler was blanked off more than 50 years ago
Just returned from a very fine SW autumn meet with about forty members and a lot of good food.
Bananaman

 

[greg brillus]

Just a thought about the breather being blanked off, I have seen bikes with same that started spewing oil from the cap after a fast run........ I wondered if the return oil from the engine was a more solid supply due to the crankcase scupper area being full of oil, if this may have caused your issue. I know a lot of you have had your tank breathers blanked off for years, but it is the main tank breather not the pin hole in the cap ........I am not in favor of blanking it off, but that's just me.