A: Oil Pipework Oil consumption

robin stafford

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I think when the engine is on tick over the returning oil being pumped over the heads and leaking down the rockers and push rod tubes explains why nothing is going back to the tank dispite the return side of the pump being double the size so the crank case fills up an oil comes out of the breather. I still think that I need to slow the amount of oil to the rockers
 

greg brillus

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Didn't someone post on here a few years back about the rocker feed bolt holes being opened up a bit, and this caused too much oil to bypass back into the sump........when altering these things you need to be careful not to get carried away........
 

greg brillus

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Perhaps disconnect your return line at the base of the engine and run a length of flexible line into a clean container, then run the engine to see what it does.......It wont hurt to run it for a short while, that will give you some idea of what is going on.
 

robin stafford

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Greg yes exactly what i was thinking I have a funny feeling that will cure the problem but using 0/30 oil if that speeds the flow by that much it seems a shame to cut the rocker feeds down
 

greg brillus

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Your oil sounds too thin to me.......Do you know what your rocker feed bolts are.......Stock ,or the ET 100/1 Mod type.......Is it possible something has failed........ The bleed holes in the ET100/1 bolts are very small........could there be a restriction in your return line.......perhaps swollen up.
 

robin stafford

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I have the standard rocker feed bolts that do not lock the rockers in the tunnel the return lines are new thicker oil will probably cure the the excess oil passage down to the cams and probably cure the problem. but I like the idea of using thin oil vincent owners always want to change things
 

davidd

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I now remember Neville's article, but not enough to discuss it. I put locking rocker feed bolts in David Tomkins' engine and he drilled out the oil holes. I remember checking Neville's article at that time. David runs the thinnest oil he can and it has worked well for him with no oiling issues. I can only say that the engine has good drainage and no leaks.

It is a little work, but I wonder if you could check the output of oil as Greg suggests and run the same test with the output of oil at the return. It could be timed and run at a similar rpm to see if there is a large amount of oil difference. It would tell you if there something to worry about. But I am not certain that the problems you are experiencing are not just a number of known, but small issues like breather timing or routing the tube vertically, locking rocker feed bolts, guide drainage, leakdown problems, etc.

Sometimes the cases have damaged scrapers or holes drilled through the bottom of the scrapers, which can alter the normal flow and scavenging of the engine.

David
 

ernie

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Didn't someone post on here a few years back about the rocker feed bolt holes being opened up a bit, and this caused too much oil to bypass back into the sump........when altering these things you need to be careful not to get carried away........
That was Neville, as RS above mentions. I think with such thin oil you should have metering wires in the rocker feeds. I also question synthetic oil in classic air cooled engines. When I tried it I suffered wear on the valve stems and upper guides.
 
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