Does anyone know what the factory bypass pressure is for a sbc federal mogul high volume oil pump? My oil pump is a high volume but not a high pressure? I know there are at least two springs and one will give you high pressure and one is the stock pressure for the high volume pump. Are the high volume pumps set at a lower pressure so you do not pump your oil sump dry?

I pumped out my 30 wt oil and tried some 40 wt. At idle the 40 wt is higher. At wot the pressure is the same for all oils that I have tested. This makes me think that the max pressure is being controlled by the oil pump bypass spring. I tried to do a search for these pressures and could not find them.


thanks

On the circle track motors (sbc) that i have built a high volume pump w/std spring usually gives us 60 psi +/- 5 ,the stiff spring usually gives us 80 psi(overkill unless you got alot of rod or main clearence). These #'s varie with rod/main clearence,Smitty

I having been trying some different oils. The max I ever see is 40 psi. The difference between 10-30, 30 and 40 wt is at idle. I will get from 10 psi to 20 psi hot idle depending on oil.

Runing a small block with no oil cooler the oil does get very hot. Is there 20 psi loss from the oil pump, filter up to the point where oil pressure is measured on the top of the engine. My sensor is at the top of the engine near the intake manifold. If you use the sensor hole on the side of the motor above the oil filter is there more pressure there? this hole has my low oil pressure alarm sensor in it.

I know there is guage and sensor error. I have rebuilt the engine twice and I get the same numbers. I wonder if the sealent that I put on the sensor threads might have something to do with the max number that I see. Does anyone put the oil sending units in dry with no sealent?

Thanks

Get an oil cooler. It's really not that hard to plumb and it will make a lot of difference. My ski boat has a 350 Mag and no oil cooler and the oil gets quite hot pulling a skier at 3500 for 5 or 10 minutes. At idle the pressure will drop to 10 pounds. I wouldn't want to go any distance at high speed with this set-up.

40 psi max is kinda low for a smallblock,i would make sure there are no fittings,hoses or lines that have too many 90's,bends restrictions etc. A oil cooler is also a must. I had some inferior fittings,lines etc on my 502 at one point and my max oil presure was real similar,after eliminating some adapters that were pretty small on the id and excesive 90's i gained 20 psi,the lines can't produce oil pressure but they can sure restrict it. With a small block i wouldn't use ANYTHING that has a id ANYWHERE that is less than .420 (7/16),preferably 1/2 inch (or -10 an),Good luck,Smitty