A: Oil Pipework Oil consumption

[greg brillus]

I don't think the Vincent engine is well equipped to handle big upgrades in cam, follower, valve, and valve spring up grades.........i don't exactly know how they've done it but the Horner brothers seem to get good results.......I have spoken to ken about this many times and he often says the areas to work with are too small and restrictive........Obviously their fix was to go with roller followers, ratio type rockers and a full pressure oil pump system........On their 2 valve twins the valves are 2.25" titanium and run 170 Lb seat pressures.......My experience with cams that wear prematurely seems to be from either the cam and or followers not being hard enough.......The oil delivery through the cam spindles is very important........relying on the oil returning down the pushrod tubes is a bit of a myth, this applies to the center 2 tubes but the outer 2, the oil simply runs off the bottom edge of the tube and misses the cam all together........One answer i have heard of is to blank the lower oil returns from the timing chest back to the crank case......You may get away with this on a street engine, but on a racer it will pump oil out of absolutely every where. The timing gears act like a giant oil pump and throw oil in mass........however, this oil does not actually get to the cam lobes where it is needed.......My answer on the single racer was like Marcus's where extra oil is fed into the cam spindle and thus pumps a lot more oil out of the holes in the cam lobes directing oil exactly where it is needed. So far it looks good with no signs of either the cam or followers breaking up........I am still running the Morris castor oil in this engine, so with the easy ability to remove the timing cover (cometic gasket) I will keep a close and regular eye on them..........Cheers.

 

[Monkeypants]

My OZ Rapide has RD springs and hardware from Terry, installed by John in 2004. He mentioned that the cams had a faint line from earlier wear. That would include squillions of miles in Oz in the 80s/90s, and possibly also some or all of its UK time 40s thru 70s. Fortunately he was able to clean up the cams and followers with an abrasive stone.
So the existing cams and followers were used. New valves guides, rocker bearings, lead free fuel type seats and the RD spring set up went in along with new pistons etc.
The bike has done about 55,000 miles since then. I might have adjusted the tappets 3 times in that mileage with just slight adjustments each time.
John did use a gauge for setting seat pressure. He liked it fairly high, somewhere around that 105 for a standard engine. His own bike was at 120.
My best result for oil consumption was a trip to California and back with just 8 oz. of oil added to bring the level up at home. That distance was about 2800 miles.
Right now the engine needs new valve seals, so consumption is more like 1qt per 1000 miles.
I've used vr1 20/50 for most of the mileage.

Glen

 

[vibrac]

The fad in the sixties was Gold star valve springs I used them but I did not have a spring tester back then or the internet we just picked up tips from the club night chatter

 

[davidd]

The RD springs I have used are Gold Star springs. I set them at 100 lbs. The RD springs in David Tompkin's racer just came out last weekend. They had lost a small amount of pressure, but not bad for two seasons of championship racing.

On David's engine, I was able to fit the valves under the caps. On my racer, the top exhaust cap needed to be taller and the intake and exhaust needed thicker gaskets under the cap.

If you are in the US, you can send your head to them and they will install their springs and send them back to you. I had them do a head for me in 2009 and they sent it back correctly set with their own titanium retainers and automotive-style valve locks.

David

 

[robin stafford]

Robin wrote. Have been playing with the return on my rap, put a tee in the line with a tap on running to the tank with a clear hose so I can sea plus can moniter the amount returning to the tank. With the tap on more oil returns in the bypass hose although a bit still is returning along the original line when revved. I would say 10% like this running for two or three minutes no smoke at all and no oil from the crankcase breather turning the the tap to get an even flow from both hoses still no oil from the breather. so is it to much oil in the crankcase or changing the breathers the answer