oil pressure

[geronimo]

gm 454 CU IN big block oil pump we can increase oil pressure by adding shims to the spring in the oil pump cover<br />can you tell me which thickness of shim is required to inrease oil pressure by 10PSI<br />THANKS

 

[Bondo]

Re: oil pressure

Sure you can, But Why........<br />if you've lost pressure, you should be looking to see WHY.......Main bearings ?? cam bearings ?? worn pump ??<br />Treat the Problem, Not the symptoms.........

 

[geronimo]

Re: oil pressure

engine did not loosepressure but we are following the chevy power manual and want to increase oil pressure to approx 85psi as we have remote oil filter and dito oil coolers<br />we want to find out the increase by installing shims prior the completion of the entire engine and having to remove the engine again if results not satisfactory.

 

[vinney]

Re: oil pressure

In a marine engine we want more volume than pressure. An engine will live on 10 psi per 1000rpms. 2000/20psi 5000/50psi. The stock oil pump in a marine engine is a high volume pump. V

 

[vinney]

Re: oil pressure

The primary function of the oil is lubrication. The secondary function is heat transfer. thats why we want higher volume to evacuate as much heat as possible. There is no air passing the engine in a boats engine compartment. v

 

[jasonnb]

Re: oil pressure

Vinny, your comment about the stock pump being a HV interests me. I just rebuilt my 302 Mercruiser and installed a Melling HV pump. I don't know what this engine put out to start with but I believe the spec is 50-60psi., Mine puts out 90psi. I e-mailed Melling and the tech that mailed back said that 90psi would not harm the engine. This lead me to think that these may not have had HV pumps. Have you run into this before?

 

[vinney]

Re: oil pressure

Never that high. first are you sure that number is accurate could it be a bad guage. I would put a mechanical guage to confirm the data. I would think with the pressure that high. Its going to puk out some seal some were. High volume no high pressure. I would call melling again and get some one different. V

 

[geronimo]

Re: oil pressure

Chevy power manual edition 6 under chapter lubrication of the mark IV big block that :<br />the basic requirement to prevent excessivebearing wear and failures is a steady , non fluctuating supply of clean oil between 150 and 27O degreesF AT 65- 80 psi pressure ......<br />And further at page 38 under the chapter oil pump :ANY OIL PRESSURE ABOVE 65 psi AT OPERATING SPEEDS IS SUFFICIENT FOR HIGH PERFORMANCE USE......<br />thats the base of the initial question to increase pressure to 80 psi

 

[vinney]

Re: oil pressure

Plug in a mechanical guage. Thats realty. The engineer can state what they want. But the real world is different. The oil pressure may come up to 80 psi when the engine cold and you are running 50 weight.It wont stay there very long on formulas they run oil pressure guages with a low pressure alarm. After a hard run when you bring the engine back down it will trip the low pressure alarm. That realty. The book can state any thing. But the real world is always alittle different.Unless you have an ac system on the oil system the pressure wont be up that high. As for what come out of a late model big block marine engine its a high volume pump. Many be a truck or different application different. I known what I see from a marine engine.We can talk about books all day. If you look over time the experts change there mind I know what see in the real world application. v

 

[geronimo]

Re: oil pressure

Thanks for the side comments but i still have no answer to a simple question<br />we will install a 3mm spacer as suggested in the chevy manual in the small block chapter and let you know the pressure when priming the engine and measure it with the suggested mechanical pressure gauge.<br />thanks anyway

 

[DJ]

Re: oil pressure

Jos,<br /><br />To answer your question, yes. If you shorten the length of spring travel, it will boost the oil pressure.<br /><br />Vinney makes some VERY VALID points. Oil pressure much over 60 psi. is just impressing the operator-not the engine.<br /><br />BE CAREFUL, you boost it too much and you'll blow that engine to smitherines when the oil filter fails and you don't catch it in time. I've seen more than one hot-rodder get caught by that one.

 

[vinney]

Re: oil pressure

GM new 8.1 the hp3 uses a high-volume oil pump.

 

[kenimpzoom]

Re: oil pressure

Wondering if you guys run into the problem of emptying the oil pan with a high volume pump.<br /><br />The pump pumps all the oil to the top of the engine and it cant flow back to the pan fast enough, and then you lose oil pressure.<br /><br />Seen it in car engines myself.<br /><br />Just trying to give a different perspective. More is not ALWAYS better.<br /><br />Ken

 

[vinney]

Re: oil pressure

Marine application uses more oil in the system and we utilize a windage tray. I have never seen a marine engine run out of oil. I have buzz a few of them to the moon.

 

[Waterbugtoo]

Re: oil pressure

What's important is volume, not pressure. Go ahead a shim your pump. You'll end up with one of two things (or both) happening. The main and rod bearings will "wash out", and/or your oil filter will explode. Neither one is a pretty site, especially the filter scenerio. Cranking that sucker up to 100 psi is sure to tear your cheapy Wally World filter wide open! Even with a rated filter, the bearings will still suffer. If you're showing at least 60 psi or so at wide open......leave it alone!!!! Thats plenty!<br /><br />

 

[ODDD1]

Re: oil pressure

Ken, you are not the first person I have heard make that statement.....and I have wondered about it myself....have talked to alot of people who voiced concerns about holding too much oil in the top of the engine....but I always thought, gee if you have an adequate supply comin out of the pump, you are gonna need a BIG leak up above the crank to make this into an issue.....in a healthy engine with no abnormal clearances, I cannot see where it a high volume pump would be a problem, other than eating horsepower to turn its larger size....in a older, high hour engine that for some reason or another is out of the boat [pan off] a high volume pump will help maintain hot idle pressures on the guage where people are comfortable with them.....<br /> high pressure pumps on the other hand, I have never had a use for....stock pumps have adequate pressure....in hact the last hi-vol pump I put in a small block, I had to take the hi-press spring out and install the other[supplied with pump] standard press spring.....this was on a 2700 hour small block...it carried 35 psi hot or cold.....

 

[geronimo]

Re: oil pressure

hi guys we completed the engine and result of shimming spring in oil pump cover with a 2mm shim was an oil pressure (cold) of 85PSI<br />SO IT LOOKS GOOD SOFAR