Oil Pump

[Thunderbutt]

I,ve got the motor out of the boat, to rebuild so to speak, bearing's ring's etc. One of the guy's here is telling me that a stock GM oil pump is as good or better then the after market ones. I alwayes had a high volume pump and was planing on putting in a high volume and high pressure. Do I need the high pressure?

[Kindsvater Flat]

volume makes pressure unless there is a big hole.

[Infomaniac]

I set the pressure with a .060" washer.
I do use the HV pump unless there are external oil system accessories.

[h2ojet001]

info
is the washer you are talking about in the cover of the oil pump and held in by a pin. if so what is the secret to getting the pin out and which end does it come out.
Barry

[obnoxious001]

No big magic to get the pin out, you just need a tiny punch. Take it out carefully so you don't put your eye out with the spring. I use a phillips head screwdriver to hold the washers and spring in place while I replace the pin, and then I use a center punch and carefully pean several little dots around the pin so I won't fall back out. Having done lots of turbo engines, many times I would use .180" (about 3 #10 AN washers ) to bring the pressure up to compensate for the external flow of oil, but probably a single .060" washer would suit most NA engines.

[GofastRacer]

Originally posted by Thunderbutt
I,ve got the motor out of the boat, to rebuild so to speak, bearing's ring's etc. One of the guy's here is telling me that a stock GM oil pump is as good or better then the after market ones. I alwayes had a high volume pump and was planing on putting in a high volume and high pressure. Do I need the high pressure?
Stock pump is plenty adequate as long as you're not supplying oil to accessories, you can only push so much oil through the passages. The key is clearance, rotors to cover .0025. A rule of thumb on pressure is 10 lbs per 1000 rpm. With the proper clearance, a .060 shim you shouldld't have any problems!..

[DansBlown73Nordic]

I have run a stock pump in my Stevens for about four years. My reason for this is I have a stock Chevy pan and figured it would have a better chance of not empting the pan. So far it has worked fine.

[Thunderbutt]

Originally posted by Dans66Stevens
I have run a stock pump in my Stevens for about four years. My reason for this is I have a stock Chevy pan and figured it would have a better chance of not empting the pan. So far it has worked fine.
Dan, I forgot to say I have a 14 qt pan.

[Infomaniac]

Originally posted by h2ojet001
info
is the washer you are talking about in the cover of the oil pump and held in by a pin. if so what is the secret to getting the pin out and which end does it come out.
Barry
A 4D nail works good if you do not haave a punch that small.

[Moneypitt]

The biggest waste of manufactured horsepower is excessive oil pressure. As gofastracer said, 10 lbs per 1000 rpm. That means 60 lbs at 6000. Anything more is wasting that power you're trying so hard to make. If you have the "How to hot rod BBC" book, read the oil pump section. Alot of GOOD info there. If you don't have the book, buy it, and read it cover to cover.....Most new oil pumps are NOT ready to run in any type of performance application. You MUST take them apart, check them and modify as required to bring them into tolerance. I have NEVER added shims to the pressure relief spring, IMO this is totally un necessary, as the stock bypass spring will give you plenty of pressure.....Again, do yourself a favor and buy/read the book.....Moneypitt

[Infomaniac]

There are lots of opinions on this subject and I do not disagree with any of them.
10 PSI per 1000 RPM is a very good rule of thumb for the main and rod bearings.
I push the limit on valve spring pressure with hydraulic roller lifters. A bit more oil pressure for this scenario is why I shim the spring.

[cstraub]

We recommend a stock pump and up grade the spring. I trust the boss on this one.
Chris

[h2ojet001]

how do you measure the gear end clearance on the pump? do you take into consideration the gasket thickness when setting the clearance? is this a necessary check or if it worked before just leave it alone.
Barry