[Diy_efi] [ot] Oil pressure during cranking ?

[Rob Weinstock]

>When cranking an engine over, do most crank driven oil
>pumps generate much pressure or do they have a minimum
>crank speed before they raise oil pressure ?

I believe the oil pressure should rise linearly as a function of RPM, until 
you hit the threshold of whatever oil pressure regulator is in there.

In a similar instance, a Mazda 13B rotary built up oil pressure just fine 
after merely cranking. Please note that the engine is effectively empty of 
oil, and oil now needs to make it up the sump pipe and into the pump. In 
some cases, the oil system can fail to establish prime. I'm not sure what I 
would have done in that case, as the oil pump is driven from a gear on the 
"distributor" shaft on a Mazda rotary.

Regards,

Rob