BgGy_Z28

I'm sure this has been beaten to death, but.

I now have 50 mi on a fresh 383 stroker. I had the builder put a HV oil pump on, only to search here and find out I should leave the stock size pump on with a stock pan. I removed the HV pump but seeing as the builder welded the pickup tube on, I just switched the casing. So I now have an M155 pump with the HV spring inside.

What info I'm looking for is: Should I remove the spring and put in the white spring from GM or is the HV spring just as strong. I have no problem with pulling pan again, just like to know.

I'm not really happy with the pressure as is, but builder and other unbaised builders are telling me it's normal. ( It's at the rule of thumb average- 10psi-1000rpms ). Just don't like it near the red while at a stop light.

Thanks in advance, Allen

seawolf06

Difference in volume is achieved through different internals of the pump, gears I believe. Difference in pressure is achieved through the spring. It allows a higher pressure to build before bypassing it.

Standard spring in the HV pump is same as stock spring. The white spring will increase the pressure. They both probably have the same strength.

wrd1972

If your pressure is near the red at the stoplight on a new engine you have bigger problems to deal with. Sounds like bearing clearances are a tad big. The spring does nothing when the engine is at idle. At higher RPM's the spring will open to bleed off excess pressure.

Z28SORR

What weight oil are you using? If the engine was built to the "Old" race specs., you may have to run a 20W50 weight oil.