lifter oiling

D

Durango

Member
I have a freshly built french flathead that has been run for about 350 miles. When starting it after sitting for two weeks I found it had a stuck exhaust valve. After removing the intake manifold there was very little oil in the low areas of the valve valley that I thought should full. How do the lifters and valve stems get oil ? The fuel pump rod hole is plugged as it uses an electric fuel pump. Have read Ron Holleran's 1st book but there is no mention of lifter or valve stem oiling. Also have seen Walt Dupont's Video on flathead oiling but no mention there either.

I know I am leaving out too many details but don't know which ones are needed.
Thanks Larry
 
Well, if you could look in the valve chamber when the engine was running, you would see quite a mist of oil filling the chamber from all the moving parts. This lubes the lifters and lower part of the stems but not the upper part of the stem above the guide. Marvel Mystery oil injected into the carb or mixed with gas will cure most of valve sticking. JMHO
John
 
The oil under pressure, is forced into the bearings. The bearings are fitted with crank and side clearance. The side clearance is there to allow the oil to leave the bearing, creating a flow that cools the baring with new oil. As the crankshaft spins it throws all this oil up into the valve chamber, cam shaft and cylinder walls. Street engine have a tight side clearance (.006/.010) Where as a compition engine will have up to .015.020. clearance.. However toomuch clearance can causr more flow than the rings can handle.
 
Have you been babying it for 300 Miles? Run it hard, warmed up and at high speed, you'll get plenty of oil up there. This is my philosophy of breaking in engines. After 20 miles, it all go. JMHO
 
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