Std. or high pressure oil pump?
Thread Starter
Instructor
Joined: Nov 2004
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Std. or high pressure oil pump?
I've got a new Melling 10553 (std. vol, std. pressure, M-55 with the old thick casting) that I'm about to install. In the box there is a sheet that says the installed pink spring doesn't relieve pressure until around 70 psi, and to install the non-colored spring to run at standard pressure. Unfortunatley, there was no other spring in the box.
My question is this: If I want my motor running at stock specs for non-competitive use, is the pink spring that it came with OK?
Seems to me that the pump will operate the same at the lower and mid RPMs, and will just be able to build more pressure at higher RPMs...so most of the time, the spring choice won't matter (don't know, just a guess). I was concerned about the additional load put on the engine and distro gear when driving a high volume pump with stock bearing clearances, etc. (which is why I chose the 10553), but should I have them send me a non-colored spring for those same reasons, or does it not really matter?
My question is this: If I want my motor running at stock specs for non-competitive use, is the pink spring that it came with OK?
Seems to me that the pump will operate the same at the lower and mid RPMs, and will just be able to build more pressure at higher RPMs...so most of the time, the spring choice won't matter (don't know, just a guess). I was concerned about the additional load put on the engine and distro gear when driving a high volume pump with stock bearing clearances, etc. (which is why I chose the 10553), but should I have them send me a non-colored spring for those same reasons, or does it not really matter?
Thread Starter
Instructor
Joined: Nov 2004
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Thanks for the reply zwede. I also called Melling and they said for a 350hp 350, the pink spring would be fine (maybe they just didn't want to send me the other spring?...nah).
Safety Car
Joined: Nov 2005
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From: Lompoc, CA. Santa Barbara County
I run a big block pump in my small block. Contrary to what everyone tells me, there is no such thing as too much oil pressure or too much oil volume. I prolly use 25 hp just turning that thing. My new valve covers are leaking, so there are consequences.
Bee Jay
Bee Jay
Melting Slicks
Joined: Mar 2002
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From: Beringen
I read somewhere (I think it was a work of D. Vizard) that you need approximatly 10 psi per 1000 rpm increase, so this would call for a 70 psi oil pressure for a engine running at about 7000 rpm. Limit would be around 65-70 psi.
It depends on the purpose of the engine built.
There are three variables to oil pumps : volume, pressure and viscosity of the oil.
If you have large bearing clearances (as in high perf. engines) and you use a synthetic low viscosity oil (like 5W40 or something) it may warrant the use of a high volume oil pump.
In my engine I run large clearances plus an oil cooler, plus synthetic oil. The engine was made to run in excess of 7000 rpm, so I used the Melling HV HP pump to make sure it gets enough oil.
The problem is not on the high side of the rpm range, but at low rpm, where the pump produces less pressure and volume.
Yves
It depends on the purpose of the engine built.
There are three variables to oil pumps : volume, pressure and viscosity of the oil.
If you have large bearing clearances (as in high perf. engines) and you use a synthetic low viscosity oil (like 5W40 or something) it may warrant the use of a high volume oil pump.
In my engine I run large clearances plus an oil cooler, plus synthetic oil. The engine was made to run in excess of 7000 rpm, so I used the Melling HV HP pump to make sure it gets enough oil.
The problem is not on the high side of the rpm range, but at low rpm, where the pump produces less pressure and volume.
Yves
