metering oil pump ?
 

Ok so this is NOT a thread about whether or not to block it off and run premix.

How does the metering oil pump work? What drives the pump? Is it a set of gears like the oil pump or is it diaphram type pump?

the oil pump is driven by a chain in the front of the engine, at the front housing.

I was asking about the metering oil pump that squirts a little oil into the combustion chamber to lube the apex seals...not the main oil pump

OMP
 

The oil metering pump works like this:
oil is taken from the front cover through the oil metering pump via a small gear mechanism driven by the motor. Depending on how open the throttle is determines how much oil gets into the lines. The oil lines themselves are connected to engine vacuum. This is how the oil is pulled from the OMP to the engine. The engine just sucks it in. On some older engines the OMP hole is blocked and you can't really see it flow, but on others you can see it drizzle in if you hit the throttle from the carb. Looks something like getting the last of a soda through a straw...
At least, that's my understanding. Standard disclaimer applies. :D

I don't think vacuum does very much. The oil lines from the OMP are under pressure. If you tried capping them off, it'll blow the cap (or the rubber tips) off the lines. Also, the later engines are under boost, so uh yeah. ;)

Cool, thanks

so to block off the OMP all I have to do is pull the gear(s) out of it and it will no longer pump oil.

Or I could just remove the oil lines and plug the holes to with stand what ever pressure is in the lines.

I was thinking that I would need to make a block off plate....