Chevyguy358

iTrader: (4)

I remember running across a post quite awhile ago in which someone had shimmed the oil pump spring for more pressure, does anyone know how to do this? I am already using a gm "white" spring and would be comfortable with just alittle more pressure. thanks

SS RRR

iTrader: (2)

A white spring should be more than adequate. What kind of pressure are you running now?

Chevyguy358

iTrader: (4)

when hot only around 20psi with 20w50. I've torn it apart a few times thinking there was something wrong but all the bearings look good. its only got 1,000 miles on it, I guess the builder really gave me some wide clearances

SS RRR

iTrader: (2)

I'm at 17psi at hot idle. As long as your pressure is not dropping during WOT runs and is at least 10psi per 1000rpm then you will be fine.
You may want to talk to your engine builder to see what they have to say as well.
If you want more pressure you can always get oil restricting pushrods.
http://www.pushrods.net/

shbox

If you are intent on shimming, all you need to do it put a washer between the spring and the roll pin to compress the spring a little. I would say that 20 psi hot is good, though (as long as your higher RPM pressure is to your liking).

Chevyguy358

iTrader: (4)

thanks, shbox. I see you have decided to venture on this forum. Good to have ya

edcmat-l1

iTrader: (10)

Hate to break it to you guys, but shimming the spring does absolutely nothing for oil pressure @ idle. Actually, all it does is increase the high side oil pressure. You see, the spring and ball are a pressure relief valve. When the pump gets to a certain pressure, it blows the check ball off the seat. The spring pressure is what the oil pressure has to overcome to blow the ball off the seat.

You can shim it all you want, it will never increase the idle oil pressure.

If you want to increase the idle oil pressure, you need to run a higher volume pump, bigger pump, closer tolerances, etc.

shbox

Seems like it did years ago, but maybe I don't remember so well.

ss.slp.ls1

iTrader: (36)

^^^What he said.