Hello. As you know the Vincent is meant to have a dry sump. Mine doesn't. If left for a period of time the sump does not fill. It remains dry. After a run it does. I went for a 15 mile run yesterday. When I left the sump was dry. On return the sump had 250ml of oil in it. I have inspected the oil pump and it appears in excellent condition. (I bought a replacement oil pump anticipating this would be the problem). It has a Conways anti sumping valve fitted. I checked the oil line that returns to the tank from the pump with an oil pump can and it returns easily. It is not blocked or partially blocked. There is oil returning to the tank. I think the pump is not scavenging enough oil. I have been advised that there a plugged line below the oil pump that is used during manufacturing that is plugged off on completion of the case. This plug can be too long or can become bunged up and restrict the flow of oil to the pump. I have been advised to remove this plug and check the length of it and clean any debris. This is not an easy job for me. Does anyone know more about this plug - the diameter/thread/length? Is this the correct thing to do or are there any other possibilities?
OP: Oil Pump Oil Sumping
- Thread starter Tommy Shields
- Start date
I am not sure that the scavenge pump should leave the crankcase dry, but could be wrong, I did take a quick look at Richardson and KTB but could not find a definitive answer, what do you see at the oil return orifice inside the filler cap, a sort of healthy pulse of oil returning or barely a dribble, I guess if it was not scavenging enough eventually you would have a lot of smoke out of the exhaust or worse, when you say your sump (misnomer) is completely dry, is that after you have removed the drain plug and drained off all the oil and then checked at a later date, if so then your Conways device is working, personally I would not use one, I see it as a restriction and not desirable, after a lay up I just drain off the excess and pour back into the oil tank, taking great care that whole procedure is scrupulously clean.
between 1 and 2 cups of oil remaining in the motor is normal, if its completly dry then you have a problem. Are u sure you need the anti sumping valve - they have been known to fail resulting in destroyed motors.
BTW the scavange side of the pump has double the capacity of the delivery side
BTW the scavange side of the pump has double the capacity of the delivery side
I did fit an anti sumping valve on my Norton Commando about 27 years ago along with an oil pressure gauge just to be sure oil is on its way. Done 50000 miles since then and my engine is still going strong with exactly the same oil pressure as in 1990.
No oil pressure on a Vin so I made a tell tale clear pipe on the return line just before the oil tank of my Norvin, same principle as the Egli design, so I can see if oil is circulating as it should past the Conways valve. It works just great so far after about 20000 miles.
Even if my experience taught me that an ASV can be totally reliable, I wouldn't recommend to fit one without a mean to check if oil is circulating without having to look into the oil tank.
Eric
Tommy,
On the twin, if you look at the oil pump cap and then go straight down, there is a crank case stud that is holding onto the last hole in the prop stand plate. Just to the rear of that stud is a grub screw. If you screw out that grub screw, the oil from the sump chamber will spill out. You should be able to feel it if you cannot see it. The hole is not very large, so I think metal flakes would drain out, but larger debris would stay inside.
I feel that the risk of engine damage when compared to the aggravation of draining the sump is too high. If you're riding every day or every few days, you don't need to worry. If you ride once a month, I would drain the sump.
David
On the twin, if you look at the oil pump cap and then go straight down, there is a crank case stud that is holding onto the last hole in the prop stand plate. Just to the rear of that stud is a grub screw. If you screw out that grub screw, the oil from the sump chamber will spill out. You should be able to feel it if you cannot see it. The hole is not very large, so I think metal flakes would drain out, but larger debris would stay inside.
I feel that the risk of engine damage when compared to the aggravation of draining the sump is too high. If you're riding every day or every few days, you don't need to worry. If you ride once a month, I would drain the sump.
David
Tommy,
Given your scenario, my first job would be to remove the ASV and go back to std and see what changes. If nothing changes and you re-fit it, then be sure to thoroughly prime the oil supply line again from ASV to crankcase. (I just heard today of a local young chap who failed to do this on his late father's Rapide and is now faced with a full engine rebuild - which he can't afford).
Meanwhile, the grub-screw in the crankcase is 3/8BSW x 3/8" and item 30. Which is different from the two in the Timing-Cover which are 5/16BSW x 3/8" long, item 221. Most replacements have Allen key sockets which make them easier to fit and remove.
Peter B
Given your scenario, my first job would be to remove the ASV and go back to std and see what changes. If nothing changes and you re-fit it, then be sure to thoroughly prime the oil supply line again from ASV to crankcase. (I just heard today of a local young chap who failed to do this on his late father's Rapide and is now faced with a full engine rebuild - which he can't afford).
Meanwhile, the grub-screw in the crankcase is 3/8BSW x 3/8" and item 30. Which is different from the two in the Timing-Cover which are 5/16BSW x 3/8" long, item 221. Most replacements have Allen key sockets which make them easier to fit and remove.
Peter B
Hi Peter
I think my ASV is working fine. If the bike is left for a while the sump does not fill up. It's when the bike is ridden that it starts to fill. I have transparent oil tubing just before the oil returns to the oil tank. It is returning.
I have been told that the grub screw can be too long or it's passage can become blocked and this interferes with the oil being sucked out of the sump. Does this make sense to you?
Unfortunately the head of my grub screw is badly damaged. I think I need to remove it and check there is nothing blocking the oil being sucked out.
Thanks
Tommy
Hi Martyn
The problem is if I have 2 cups of oil in the sump then the bike becomes hard to start. I have an electric starter fitted. When the sump is drained it starts fine. When the sump has a couple of cup fulls of oil in it the stater struggles to get the engine turning over quick enough to start.
Tommy, the original grub screw is a slotted one and generally sits level with or slightly recessed in from the bottom face where it screws into. Make sure the slot is cleaned of dirt and crud, and you are probably best to use an "Impact screw driver" and make one of the blade tips as good a fit in the slot as you can, then with a couple of good "Blows" with a hammer it should come loose. It is usually about 3/8 ths of an inch long, but the cross drilling is higher in the crank case than this. It is hard to say what if any could restrict the flow, but if something from the scavenge trough in the back of the case was big enough, it could happen. You might need to remove the case sump plug and try to flush some kerosine or similar into this hole and see how it flows out the other side once you have the small grub screw removed, and you can also clean up this hole with a small bottle brush or similar. You might be able to flush using some rubber pipe up against the hole and back flush the other way to wash away any restriction. The grub screw would be better replaced with a new one, make sure the hole is clean and free of oil and kero, and wipe a smear of thread sealant on it, then screw it home fully. Cheers and good luck.............Greg.