Ok, I've been doing some research and I'm going to attempt to make a homemade Prelub system which would otherwise cost approx. $1000. I'll keep you updated and will do my best to make a DIY for anyone who is interested. But first I have a few questions.

1. Where is the oil-pressure sender unit on the 12v Cummins?

2. Do you lose any oil pressure with oil filter relocation kits?

3. What is the purpose of the oil filter bypass valve?
Is it before or after the oil filter?

 

I don't remember the exact location of the pressure sender, but it is close to the filter. The remote filter shouldn't hurt the pressure to the eng as long as you use large enough hoses and fittings. The oil filter bypass valve is ther to protect the eng by opening up when there is more than a 5-7 psi differential. All it does is lets the oil flow from the oil pump directly to the oil galleys to lube the eng. bypassing the filter. This usually happens when the oil is cold and doesn't flow easy or if the owner neglects to change the oil and the filter plugs.

 

1) Oil pressure sender is a little to the rear of the power steering pump.

2) It depends on how much you let the oil flow, most bypass filters have a restrictor orifice to limit flow.

3) The bypass valve is a pressure relief valve, it dumps excess pressure back to the pan while still maintaining some flow though the engine. It's on the inlet side of the filter and on your truck located forward of the oil filter housing.

Our oil filters use no anti drainback valves in the filter, if you are thinking of pumping pressure back into the port on top of the filter oil will be flowing both ways, though the lube system and back to the pan.

 

Hemi cat is right on the by pass valve. It is usually part of the oil filter mount and is use to by pass the oil filter to keep pressure to the engine. The pressure relief valve lets off excess pressure to protect the engine, pump and filter. On my 93 the pressure sensor is about in the middle of the block on the drivers side. Oil press drop would be slight on factory relocation kits. If you used small lines and long runs it could get high.

 

Ok, so if I pump oil to the oil filter inlet like the picture below, then I wouldn't have to worry about pumping too much pressure because of the filter bypass valve right? Cause, when the truck is off, I'm going to turn the preluber pump on with a switch, then once the engine starts I will turn off the switch (manually). But for a few seconds after startup before I turn off the preluber pump, both the engine oil pump and my preluber pump may be on at the same time causing a lot of oil pressure I assume.



I didn't know our filters don't have an anti-drainback valve but I assumed oil would go both ways: through the filter and back to the pan. However, I guess this isn't a very big issue. I'm trying to copy the Preluber kit as close as possible and I don't see that they've done anything to restrict oil flow in only one direction.

What would you think is a better option? To pump oil through the top of the filter or to pump oil through the oil-pressure sender unit? If I pump through the sender unit, will the oil still pass through the oil filter?

*Oh, and approx. how hot is the motor oil once the engine reaches normal operating temperature?

 

Here's a couple of ideas for you
http://dodgeram.org/ki4cy/preluber/Preluber.htm

http://dodgeram.org/tech/engine/prelube_const.htm

I know some people who have bought these and are happy. Very simple to copy
http://www.autoenginelube.com/pages/903473/index.htm

Big complaint many people have about prelubers is that they are prone to leak.

If you tend to drive for long periods with a few engine starts each day, a preluber will probably not help you. If you don't drive for days at a time, you MAY extend your engine life. The Cummins doesn't need much help in the engine life department because it will easily outlive the truck.

 

Yeah, I've visited those sites. The guy who made his homemade preluber used an agricultural pump. I don't know how that thing would work . I think that pump is made for water and I don't think it could handle temps of up to 250 degrees F.