Page 1 of 1

4m40 oil pressure?

Posted: Wed Nov 25, 2015 7:39 pm
by Mr. Flibble
What is the oil pressure range on the 4m40? I have googled and seen various answers. Everything from 50 psi at start to 30 psi warm and running vs. 4 psi at idle and 80 psi at 3500 rpm!!!

The reason I ask is I am looking to install my jackmaster sandwitch adapter with an oil bypass. This would come right off the oil filter area. I want to then pass a small segment of this flow into my frantz filter, and then into a 55 gph wvo style centrifuge for a final pass before returning to the engine.

The centrifuge won't engage unless there is 25 psi or more available, which is good as it does not use extra pressure at idle.

Will I be able to get 40-80+ psi for a sustained period or not? Will this idea actually work on my engine?

Re: 4m40 oil pressure?

Posted: Fri Nov 27, 2015 9:44 am
by macro
I can answer this in a couple days when I get my oil psi gauge back in, I'll let you know!

Re: 4m40 oil pressure?

Posted: Thu Dec 24, 2015 12:02 pm
by Yukonflyer
macro wrote:I can answer this in a couple days when I get my oil psi gauge back in, I'll let you know!
I've been planning to install an oil pressure gauge, where are you taking the pressure from?

Re: 4m40 oil pressure?

Posted: Thu Dec 24, 2015 6:58 pm
by Mr. Flibble
Most people tee off the oil pressure switch near the bus bar.

You can get the pressure off the oil filter with a sandwich adapter, but the constant pressure fluctuations from the pump are not good for the sender on most oil gauges.

Re: 4m40 oil pressure?

Posted: Mon Jan 04, 2016 10:54 am
by macro
I teed off the switch, the threads were all different but I got it figured out eventually! I also had a hose made because the sender is a big 'ol thing and I didn't like the idea of it vibrating on the engine constantly. Seemed like a likely failure one day.