Do I need 24v oil pump for my 12v?

[thisguy65]

Building to make 350hp. While I have the motor in the stand replacing items now. One of those are oil pump, motor runs strong and came out of a bus. While searching I came across that the updated 12v oil pump is what's on the 24 valves and it flow more oil. Didn't say how much but over all more oil.

Is this basically a "stock" high volume upgrade? In gasser world high volume can suck a oil pan dry quick (only 5-8 quarts) vs the 12 we run.

[Signature600]

If I can see the oil pump, I put a new one in it. which one doesn't make a huge difference, but for a couple hundred bucks it's way too easy to change it...

Chris

[thisguy65]

Yes...oil pump, water pump, front and rear main seals, valve cover seals, and a host of other things are getting replace.

Side note: I want to be able to find a billet tappet cover that has baffle in it like the OEM. From the stories I've read, rather just get it vs dicking with the oem one. Seems they leak real easy.

[95cummins5.9]

I would just stick with the stock cover for many reasons..

[AlmostBroke]

Originally Posted by thisguy65

I want to be able to find a billet tappet cover that has baffle in it like the OEM. From the stories I've read, rather just get it vs dicking with the oem one. Seems they leak real easy.

I bought Keating's billet tappet cover awhile ago, super nice piece. Baffled and has two -12 ORB ports for ccv rather then using 1 single hose like the oem covers.

[thisguy65]

Originally Posted by 95cummins5.9

I would just stick with the stock cover for many reasons..

can i ask why? I'm new to the cummins i will admit but it seems to be a pain to get the tappet cover to seal and stay seal

[95cummins5.9]

Thr factory cover will more than do its job at 300 hp. Money can be spent elsewhere. Unless you're going for loOKs..

[BigPapa]

Agreed. Haven't had any issues with mine in 500K miles.

[thisguy65]

I just read alot about how they are a ***** to seal but haven't read on how they sealed them (Gasket and rtv or just used rtv)


Does any one run a 24v oil pump on 12v?

Looking at Cummins quick serve site they call out p/n 4939587 which is a 24v. I have a industrial bus motor but found a p pump engine S/N on here that I use to cross reference. They both show the same parts numbers for all the pumps. I did reason one post where the a guy said he saw 10 more psi of oil pressure. Which would mean more flow with same restriction (wear on the motor) = more pressure.

[BigPapa]

I replaced the gasket on mine when I put the engine in my '98 about 150K miles ago, it had 350K on it at the time, just because it was easy to get to, not because it was leaking. It was hard and brittle and broke off in pieces. I used a Cummins gasket, make sure you get it oriented properly since there is a top and bottom to it. I put a thin bead of 3M Weather Strip Adhesive in the bottom of the channel of the gasket, put it on the cover, and let it sit overnight. Put it on the next morning and haven't had any issues.

On the oil pump, from '94 to at least '01, I don't have a later ESN, Cummins now calls for the same oil pump, 4939587.

[thisguy65]

Thanks BigPapa. Mine is leaking and while it's on the stand I'm going to take the pump off to clean it up and do the tappet cover. For the actual sealing surface on the block did you put any rtv or just let the gasket do the sealing?

I've been cross referencing parts for my motors by the ESN and a Dodge. The oil pressure relief is different. My motor is suppose to open at 65 psi. Looking up what a dodge is now. Everything is the same other than the spree for the oil pressure relief.

[BigPapa]

I did not use anything between the gasket and the block.

[wildbill144]

I have a Keating tappet cover also,(along with his rear freeze plug) tappet cover seals with an o ring plus 2 baffled -12 port's. Its a lot thicker and stronger than the stock one. As far as it being a bling item, its pretty hard to see with everything in front of it, I know you said your HP goals are mild but if your like most ppl around here once the bug hits the HP goals increase fast, lol..I'd make sure your cover was flat on the gasket surface, several friends have been using permatex right stuff on there's with good results. Seems stock covers are one of those thing that are a hit or miss, some ppl have good luck and they go 100,000 or 2500, friend of mine had a nightmare one until he did the right stuff thing, 25000 mi with out a drop so far..

[kleann]

I've put the keating billet cover on stock trucks before, it's my preferred repair method if a truck has a leaking cover. One of the nice things is not having to worry about it rusting out, as I've seen some very rusty/scaly covers as well.

[tornado112]

Originally Posted by thisguy65

Yes...oil pump, water pump, front and rear main seals, valve cover seals, and a host of other things are getting replace.

Side note: I want to be able to find a billet tappet cover that has baffle in it like the OEM. From the stories I've read, rather just get it vs dicking with the oem one. Seems they leak real easy.

Since its off what about rebuild/reseal the vac pump/ps pump

[jimbo486]

The original oil pump in my 90 Cummins was superceded by 4939587. I bought it last year since the original had around 500k miles on it. I don't have any pressure values from before and the engine was also rebuilt but I see 65-70psi cold at idle with a new pressure regulator spring in the filter housing also.

For the tappet cover, a buddy of mine used the Right Stuff gasket maker on the OEM cover with a new gasket without any issues. I went billet on mine a few years ago because mine was weeping some, I was installing a new injection pump and had also heard about the headaches trying to get them to stay sealed. The OEM cover is thin and can warp or get bent out of shape sometimes. I imagine any gasket maker stuff would compensate for that though.

[9724VF350]

The current Cummins part number for both 12 and 24v oil pumps is the same. Right stuff works well for stock side cover gaskets.