Drew

What oil pump do you run and why? Stock - Stock High Performance - Melling High Performance? What oil pressure are you running?

It seems there are those that say stock pumps and pressure is fine as long as tolerances are not to loose. If you run loose then go with the Melling but make sure you have a good pan.

I am running a Big Block Chevy with factory Bearing clearances on the upper end According to Mercury Manual for 502 mag. Stock Factory GM Pan 8 gt I think. No windage tray (yet). I want to replace the oil pump and blue print it but have been questioning myself on what size pump to install so I thought I would ask some others.

Thanks Andy

Crazyhorse

I install stock pumps if the old one needs to be replaced due to internal wear. Melling offers a stock replacement as well as a high-volume and high-pressure.

Brad Perry

I went through that exact question last winter. My stock gen vi pump was perfect, but I succummed to the universal pressure of "replace the pump every time the pan is off" theory. Looked high and low for a high volume gen vi pump and never was able to get ahold of one, even through chevy hipo. Had a new melling unit that would partially bind right out of the box! Not exactly high tech stuff here. Looking really carefully, I surmised that the small shaft that the passenger gear rides on was cocked to one side. Finally a call to teague netted a blueprinted (and wired) high volume pump for I think $75. He even set up and welded the pickup for my pan. Meanwhile, the guy that purchased my old genvi short block was laughing all the way to the start key...with my old pump that worked flawlessly!

As long as this one gives great pressure, I ain't never going to let go of it, new motor or not!!

Crazyhorse

Drew, why not blueprint the pump you've got? It 's no big deal to do.

Scott

How do you blueprint the pump?

Blueman

Same as we talked about.

Drew

Crazy I will probably do as you suggest. Blue print existing pump. Deburr the gears - put in the grooves or passages to pressure balance and set end clearance. I thought I might get more feed back or opinions on whether to use a high volume / pressure pump over stock. I have had many a discussion with some of my fellow local boaters on the need or depending on your point of view the required need of a high volume / pressure pump. More is not always better.

HARRISONMIRAGE

WHATEVER PUMP YOU CHOOSE I WOULD RECOMEND A SUPPORT BRACKET AS WELL AS WELDING THE PICKUP TUBE. I LOST A MOTOR LAST YEAR DUE TO A BRON PICKUP TUBE.IT BROKE AT THE WELD.