Oil Pump question

[flanker1970]

I have recently built a 406 w/ an estimated 500hp. The rod bearing clearances are on the tight side for performance app ( just under .002").
I have a new Milodon high volume pump in the box that I did not use in a previous build. In the past, I've read that high volume pumps were not necessary most of the time and create some parasitic heat. Since this is a .030 over 400, it will probably be predisposed to more heat anyway ( no dunderhead here, steamholes drilled in dart pro 1 aluminum heads).
The car will be hipo street/ strip.
Will using this high volume pump create more unwanted heat or shall I just use it.
The reason I went with the milodon pump is that Melling had a spell of weak castings that were breaking under performance conditions. (new design).
Thanks for any input or ideas in advance. Oiling is a topic that is rarely considered by the fairweather eng builder like myself.
I would like to finish this eng this weekend but I will wait until next week if opinions direct me to a standard volume pump. Thanks again.

[R Pope]

With tight clearances, a stock pump is all you need, but the high volume unit is new, I would use it. The extra flow bypassing won't raise the oil temp all that much, and you will have better pressure at very low rpm.

[pat mccarthy]

yep i know of the weak casting of the melling pump that did fail at mount point .a stock pump would work fine like R pope said as well that your wear on the cam gear could not be as bad as making a we bit more HP from turning the small pump. if you want to run the big pump if you have a big oil pan if not at hi rpm you can suck the pan dry and you could just run a lower by pass spring in the big pump if you do not want hi psi you realy do not need the 10 pounds for every 1000 rpms at low rpm there not much load on the engine

[flanker1970]

I'll be running a Hamburgers 7 qt pan with the torque baffles. I noticed that this Milodon pump does have the pink spring ( high pressure). I'm not too concerned with the 1-2 hp loss due to extra bypass, I'm more concerned with the heat involved. Would changing the spring change the volume? I know that it would reduce the pressure. Thanks for the suggestions.

[pat mccarthy]

no but were is the hi v pump by pass at with less oil clearance? melling m155 thats a 3/4 pickup that pump would have more pickup volume then a stock 5/8 pump they have more then one by pass spring blue .yellow .pink. black ? so i would use the pump you have with out the pink spring or stock pump

[tango]

On most car's from the Factory the Oil Warning Light and Engine Shut Down is set at 12PSI . On the Buick 3.8 V6's when it would get Good and Hot out them Oil Lights would pop on at Idle . Sure Clearances to Large . We would install the HV and HP Pump kit and some New 10w40 to give them Engines a chance for more years . On a SB Chevy Street Engine built with a Nice Crank all new parts yes like it should be . The stock pump will be fine . But I still am more happy with the in gear idle oil psi when I am in traffic at out side temp's in the 90's on up with the Z/28 Pump M55A .

[flanker1970]

thanks for the replies gents. As always, lots of things to consider.

[flanker1970]

I have a stock pump that I pulled out of an engine with about 50,000 miles. Is it practical to pull the spring out of this and put it in the Milodon high volume pump? in other words-replace the pink spring. the Milodon has a 5/8 inlet like you said. Thanks again

[tango]

I did that to this Stock Oil Pump . But it had Low Miles and Check out in Like New Shape . For what the Brand New Pumps Cost . It's Best to buy one instead .

[pat mccarthy]

i will take voume over psi any day so you could bench test the pump with the stock spring see were the bypass comes in at