Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Small oil leak sometimes from motor on standing

It's just marking its spot! - 😉

As soon as you turn over the motor the oil pump will shift the oil around through the oilways and lubricate so nothing to worry about - simply check the oil tank level prior to starting and then regularly.

and just to add, note that the scavenge side of the oil pump has a considerably greater flow (typically three times) than the pressure side, so equilibrium of oil levels is quickly returned after start up as oil is pumped back into tank.

to be honest, I assumed small oil leaks were more than normal for any morgan modell

I simply put a cat crate with cat litter under the motor block.

am I wrong - and should I worry?

8,500 miles. Bone dry.

14k miles bone dry.

11k miles dry. I had a "wet sump" issue whilst on the way to the dealer. Idling in queuing traffic it cut out. It restarted at 3rd try with huge clouds of white smoke. I pulled off & phoned the dealer. We decided it was safe to carry on & the smoke fully cleared in a few miles. They cleaned the oil off the front of the engine & replaced the oil contaminated air cleaner at my cost.

Has anyone fitted a non return valve to the return oil line from the scavange pump to prevent sumping? If so was it approved by Morgan?

It would need to be on the pressure pump side. That's where there is a head of oil from the tank.

I agree with Richard that the main cause of "Wet Sumping" would be if the head of oil in the tank slowly leaked through the feed side of the pump and ended up in the sump.
A non-return valve fitted in the feed line would not stop this but if fitted the wrong way round would prevent any oil from ever getting into the engine.
The best solution would be to fit a tap in the feed line but if you forgot to turn it on before starting the engine the result would be disasterous and the engine would be wrecked very quickly.

If the "Wet Sumping" is caused by oil leaking past the scavenge side of the pump, in theory the volume of oil ending up in the sump would only be equal to the amount left in the return oil line back to the tank because the end of the return line is above the oil level in the tank.
I doubt this would be sufficient volume to cause any real problems.

Always a problem putting a ball type check valve in the oil supply of a dry sump engine.

My Velocette bike has an upside down spring operated ball valve in the oil feed from tank, such that it's held closed when engine not running. Suction from the pressure pump overcomes spring pressure to open valve when it's started. Its imperative that no air remains in this pipe though following drain down, which would otherwise compromise the suction.