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Author Topic:   oil pumps
Dirt Maniac

Total posts: 180
posted April 07, 2005 05:25 PM  
Is a stock oil pump sufficient for a decent modified motor, or do I need a high volume, or some kind of fancy pump?

Dirt Forum Champ
Total posts: 2007
posted April 07, 2005 05:56 PM  
Depends on your bearing clearances. You might get by with a stock pump if they are not excessive otherwise high volume would work. No need really for a 'fancy pump'

Dirt Full Roller

Total posts: 43
posted April 11, 2005 05:59 PM  
A high volume oil pump puts a lot of oil in the top end of the motor, I like to keep a lot of oil in the bottom of my motor. I have always used a stock volume pump

Dirt Maniac

Total posts: 103
posted April 11, 2005 07:28 PM  
I agree with the stock volume pump, but my engine builder will not put one in the motors he builds for me. He won't build it other wise. I have ran both and never noticed any real difference. But I put other items in the motor to help direct the oil in the right directions. If you get the oil back down to the bottom fast enough its all right with a high volume.Thats how i counter his insistance of the high volume pump. Some run a high pressure instead of a high volume. LOL

Dirt Freak

Total posts: 402
posted April 12, 2005 08:10 AM  
You can't have pressure with a restriction to volume. If you increase volume without increasing resistance, pressure will increase. You can't increase pressure without either increasing volume or reducing the resistance.

You pump designed for higher pressure increases the volume. Your pump designed for volume will increase pressure if you don't change the resistance.

Dirt Freak

Total posts: 370
posted April 12, 2005 10:14 AM  
I took my pump(not chevy) and put a washer behind the spring. Got a lot more oil PRESSURE. So does that mean i now have a custom hi volume oil pump? It is only stock volume.

Dirt Forum Champ
Total posts: 2007
posted April 12, 2005 12:00 PM  
no it just means the bypass in the oil pump doesnt blow off until a higher pressure. That only works if you have a good tight engine. IF your engine is worn out then it will never reach that pressure because you are not moving enough oil to make up for the leakage around bearings, etc.

It is not high volume beceause with ea rotaion it still pumps the same amount of oil. A high volume pump has bigger gears and therefore moves more oil. If you increase volume with the same restriction(i.e. clearances) then pressure will increase.

Dirt Full Roller

Total posts: 73
posted April 12, 2005 02:06 PM  
I help the machinist who does my motor stuff with assembly. I like to refer to him as the "Godfather". When I went to put the oil pump on (melling 55 HV), he about sh** his pants. "Always high pressure, never high volume" he says. It's melling 55-A from now on. 80 lbs. of oil pressure at the start, 45-50 at idle after 20 laps. And the motor looks brand new...

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