Jeep Strokers

Is the melling HV oil pump (pt# M167HVS) the one that causes clearance issues with the oil pan? Does it matter whether you use the 4.2 or 4.0 pan?

oletshot wrote:Is the melling HV oil pump (pt# M167HVS) the one that causes clearance issues with the oil pan? Does it matter whether you use the 4.2 or 4.0 pan?

Thats the right part number for the pump. From the reading ive done the 4.0L pan needs to be clearenced to fit it. Is there a difference between the 4.0 and 4.2 pans?

The HV pump is only 7mm's longer. (So what like 1/4 inch?)

In my search for the 258's timing cover I came across the 4.0's oil pump. I had intended to clean and inspect it and maybe buy the rebuild kit, but after looking at the pickup tube and body, I decided there is no way I'm putting that cruddy thing into the stroker. In my search for oil pump prices I found the HV pump and pickup tube for less than the standard oil pump alone. I had no intention of using the HV pump, as its not necessary, but....

The 258 pan has different a baffle plate inside and nice skid plate on the bottom. I don't know where the interference is. Is it 7mm taller(block mounting surface to the top plate that's held on with the 4 bolts)?

My concern with the HV pump is 0* temps in the winter. I'm afraid of breaking the drive tabs trying to pump high volumes of molasses thick oil. I guess I could run 5w-20 or 0w-whatever with a ZDDP additive in the winter instead of the thick diesel oil.

Where did you find a HV pump for cheaper than a standard? The cheapest I could find any pump was 64.90 for a standard. I only checked a few places: Advance, Napa, Direct connection and summit, but the I finally ended up going with a rebuild kit supplier.

The key was with a new pickup screen. Advance sells the HV for $71.48 and includes new screen. Standard pump costs $85.48 no screen included.

Have you tried to fit the tube to the pump yet?
John

John wrote:Have you tried to fit the tube to the pump yet?
John

When i just replaced my oil pan gasket for the second time i also replaced the oil pump and screen.

It was a bitch!

I tried to freeze the screen and heat up the pump, but that made no difference at all.

I didn't have the "tool" that your supposed to use, but i had always heard of using a crescent wrench... so i used that.

I thought i was going to demolish the ring that stops the screen from going into the pump any further. Its what the wrench would rest against when i was pounding the wrench with a hammer. I removed more material from this "ring" then i would have liked too, but it all finally went on well.

FWIW, i also read (FSM, or Haynes cant remember) its a good idea to use a high temp sealant on the screen's shaft that enters the pump housing. I used the same stuff that i used on my head bolt that drops into the water jacket above the water pump. Seamed to work well.

I use a bar clamp from a tube flaring set, clamp the halves on the tube, then you have something to press on. And yes, Linda has gotten used to my things in her freezer and oven.
John

John wrote:Have you tried to fit the tube to the pump yet?
John

No, I just ordered it from Advance last night. Melling HV pump and screen $77.73 with tax. They had a Sealed Power HV with screen for $63, it had to be drop shipped from sealed power and I wasn't sure who made it (probably a reboxed Melling), so I opted for the Melling. Melling HV pump was stocked at one of Advance's warehouse so they had total control of getting it to me. I didn't want to go in there and ask "Where's my pump?" and get "Sealed power says it should ship on the (insert date here)."

I remember reading in the FSM about not clamping it across a certain area to put on the new screen, that even slight pressure could damage it. I'll have to review the FSM before putting on the screen. I know me, and I'll clamp it right where I wasn't supposed to if I don't.

*I thought I was the only one who did that!!! The lessons I have learned the hard way I still remember.
John

You can't please everyone, but it IS possible to make' em all mad at the same time.

OK, apparently I was doomed to screw this up from the beginning. I thought I found an easy way around the HV pump not fitting the oil pan. I could just use that 258 pan. It looks like it has clearance where the 4.0 pan doesn't. All I'd lose is a quart of oil, as it's a 5 quart pan, I believe. Here is my mistake, the pickup tube that comes with that HV pump is FOR THE 4.0 PAN. Now I have to buy the right pickup tube for the pan and use the 258 pan that I cleaned up, stripped and repainted or beat the hell out of the 4.0 pan to make it fit. Still not positive the 258 would clear the HV pump anyway or that the 258 pickup would fit the HV pump.

Today went better than yesterday. I removed the 4.0 pickup screen and test fit the 258 pan over the HV pump without a pickup screen, no interference even without a gasket. Autozone was able to get a pickup screen for an '88 258 in the store before I left work today, only $12 too. I put it all together, checked clearance between pickup and pan (about 1/2") and bolted it on.

Only problem I ran into was locating that skinny strap that goes over the rear "hump" on the pan. I'm not really sure what the straps function is or how important it is, left it off for now. Garage needs a good spring cleaning, hopefully I'll find one of the two i had.

It all depends on your bearing clearances rod, main and cam and from there lifter bore clearance. 99% of the street performance engines we build e use standard volume high pressure pumps.On all our engines build we line hone all our blocks and hone the big end of the rods and try to maintain .002 to .0025 on the rods and mains for street performance and if the cam housing bores are over size we line bore them to the correct size.I'm running a STD Melling pump on mine with no issues of oil pressure on 10-30 oil. 45-50psi at idle and about 60 at 8000rpm. Our 408 Pantera also runs a std oil pump. Not sure the brand.

jonemere wrote:It all depends on your bearing clearances rod, main and cam and from there lifter bore clearance. 99% of the street performance engines we build e use standard volume high pressure pumps.On all our engines build we line hone all our blocks and hone the big end of the rods and try to maintain .002 to .0025 on the rods and mains for street performance and if the cam housing bores are over size we line bore them to the correct size.I'm running a STD Melling pump on mine with no issues of oil pressure on 10-30 oil. 45-50psi at idle and about 60 at 8000rpm. Our 408 Pantera also runs a std oil pump. Not sure the brand.

This is correct thinking and application. HV pumps are for loose clearances and/or high RPM. Rule of thumb is .001" of oil clearance per inch of journal diameter for performance applications. One thing a lot of people do not take into consideration is that the stock pan capacity of an engine is related to oil drain back rate and supply requirements at design RPM in order to assure there is always oil in the pan. If one were to run loose clearances at higher than design RPM with a high volume pump it would be possible to pump the stock pan dry. If your clearances are correct and you are operating within the design parameters there should be not be a need for an HV pump.