What different will it make to use a 11 Psi oil valverlief in the hole beside the center hole than a 30 Psi valverelief,no valve in the centerhole,havn`t got a 30 right now and want to try an engine,(500Efi) thanks.

I left the 11psi in the center and used a 30 in the outside...made a big differance

Ok,but the last time this was up here on OSO,the wise guys told to take the midle one away.

You should plug the one in the filter pad ( i believe it is the 11lb one. Best way is to tap and thread a plug in it. But you will have to have a bare block to do it right. since you make some metal shavings it would be good to boil the block afterward. Some people are installing small freeze plugs in place as well. (im talking about the one that is not the center but the offset hole)

this was posted over on SOS. looked here he may have a different user name over here. but either way it is awesome information and a great read. everything makes sense.

http://www.seriousoffshore.com/forum...&highlight=oil

Thanks Fixxxer22,
but I still don`t get it, after the last discusion here on OSO the last word was to leave the centerhole open and put a 30 Psi valverlief in the offset hole,I have used this without trouble.I`m not going to modify this HP500Efi it`s original,but new bareblock,can I use the original setupp with only valverelief in the offset whole and nothing but open midle hole?

Arcticfriends on here....

502 Magnum - I feel your pain. I had a black oil problem in my 502 MPI
from the start. I too did a lot of reading and I thought the solution
was identified. However you are now getting contradictory advice and
in a discussion months ago on this issue Raylar chimed in with advice
that was different from what I had learned years ago. So I will NOT
say Ray is wrong since he is an expert but I will only tell you what I
did and why.
So as for your questions: Putting the 11lb. bypass in the OUTER
location will send more oil AWAY from your filter and cooler due to
resistance in the oiling system. This is why a 30 lb. bypass is used.
Many people plug this outer hole so that ALL oil is filtered and cooled.
This is what I did. Remove the bypass in the center hole period. I
talked to a few local engine builders and they said that in a boat all
the center valve does is restrict oil flow. I did not want that.
HP500's and HP525's are different! They may not have bypass valves
in the blocks at all since they use a different oil filter mount. When
I was going through this hassle I had my mechanic check two black
502's and two blue 502's(an HP500 and an HP525). Only our black
502's had the bypass valves. Mine had two, was stock and never
previously worked on. The other black 502 just came from a machine
shop and had no bypass in the center hole.
I removed both bypass valves, plugged the outer hole, installed an
oil temperature gauge and run an oil filter with an anti-siphon valve
and a bypass valve built into it. Baldwin B279. My oil is cool and
clear. It used to turn black in about 5 hours. Good luck.

Thanks guys,to be clear I agree with the last speaker,thanks again nice hearing from you.

Leave the center one out, you can either plug the outer one or use the 30psi valve. Either way will work.....