1972 combat oil pump question.

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The term "wetsumping" is a little misused these days as wetsumping used to refer to proper wet sumping IE whilst the engine was running the scavenge side of the oil pump couldn't keep up
If this is the case?-old definition...
I have had only one oil pump I tested on my rig to prove, to a friend with a combat, that continuous wetsumping was occurring. Unprotected scavenge feed had compromised the return gears...became worse as the oil got hot and thin. Reported that new pump fully restored proper feed/scavenge function.
 
Has anyone had the AMR mod done recently? I’m ready to pull my timing cover off and send it to them. Yes, I’ve emailed them but wanted to check with the herd too.

Wetsumping refers to a dry sump engine (like the Norton) turning (temporary) into a wet sump engine.

As for the OP if they have a MkIII timing cover then it also has a check ball. The oil pump also needs to be a MkIII, but that’s a LONG story.
 
Wetsumping refers to a dry sump engine (like the Norton) turning (temporary) into a wet sump engine.
IMO:
Not incorrect but incomplete description of wet sumping which is excess oil in the sump.
1. Feed side leak down through the gears/shafts while stationary

as my description above, rare but especially in 200k engines.
2. NOT temporary is failure of return side of pump to scavenge the sump dry while running.
 
I use 2 terms.

Static wet sumping, from the bike sitting unused and oil leaking past the pump gears.

Dynamic wet sumping, the return side of the oil pump cannot keep pace with the feed side as the engine is running. This could be an issue with the pump or a blockage on the return side.
 
MkIII timing cover then it also has a check ball
The MK3 cover has a plunger, the AMR method uses a ball, the plunger seems prone to sticking part way to the shut position and causing the MK3 version to fail to stop wet sumping.

If you go AMR then send them the pump as well, they machine it for O rings to stop the oil leaking from the feed side to the return side and hence to sump before it gets to the new timing cover check valve.
 
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