oil pressure relief valve

[digger]

how do you check if the oil pressure relief valve that screws into the underneath of the block is ok? Should the little piston be able to slide abit when you shake it back and forth? or should the spring preload it? Under gravity the pistons sits 8mm below the top surface.

What is the function of this relief valve as compared to the one in the pump?

Thanks

[strad]

I'm going to bump this, because I have the same question re the oil pressure relief valve. Also read somewhere that Febi pumps are not the best -- anyone care to confirm or deny that?

[AdamF 88iS]

I'm going to bump this, because I have the same question re the oil pressure relief valve. Also read somewhere that Febi pumps are not the best -- anyone care to confirm or deny that?

The only way to tell with that thing is to compare it to a brand new one... but in all the many M20s I've built, I've never had to replace one. They don't ever go bad.

The one and only time I've seen a Febi pump used it was directly responsible for teh seizure of that engine.