Non Porsche engine advice needed: Jeep 4.0
 

I'm refreshing the engine in my Jeep and adding a few mods. Among other goodies a Mopar Performance high pressure/volume oil is going in. Unfortunately there is interference between the pump and crank. I've removed material from the pump and the crank spins freely now, but how much clearance is enough?

What do you guys think? .05"? .125"? ???

I've never heard of a 4.0 oil pump going before. I would honestly just use an OEM.

The original part can't be reused and the Mopar unit was a gift from my brother, so that is what I'm using.

What does it say in the Mopar Performance catalog? I've never seen them fail to note if something needs clearanced, and how much. I'm with Sniper, I've NEVER seen a 4.0 pump die. It's usually the bearing clearances opening up that drops the oil pressure. But what do I know, one of mine has 300K on the clock, and the "new" one only has 250K on the clock. Neither have ever been apart. Both do sound like Isuszu diesels though.

I did some searching on "The Web" but found nothing to help you.

You may want to PM Pelican SCHNELE. He works at a Chrylser.JEEP dealership. He may be able to find out more.

Having owned at least 6 Jeeps with the 4.0 I can also attest the oil pump will be the last thing to go, but that is not the issue. What part of the pump are you removing the metal from? I would try to get as much clearance as you safely can without compromising the pump.

The cast body of the pump is pretty thick, and I've removed about .07" of material to get good(?) clearance.

The only note from Mopar was about having to 're-work' the oil pan. I just put the hammer down...

*Note* I am not a Jeep expert and I did NOT sleep in a Motel 6 last night...

That said, I really think that you need a bit more clearance for safety. It would seem to me that with a fairly large displacement straight six, there could be more of a whipping action with the crank, a little bit of flex, and the inevitable expansion of heated parts. Plus, let's be honest, Jeep manufacturing tolerances are not the same as Porsche's - LOL! ;)

The .125 in the afore mentioned robust casting certainly seems safer to me. I'd be much happier to accept a failed oil pump than a crank-pump collision...

angela

Angela explains the need for clearance much more eloquently then I did!

Well, I've got .05 clearance in all but one spot. I'm going at it again and should be able to get .10" by reworking one spot. The leading/corner edge of the counterweight is closest right now at .012".

Thanks for your help! But I'm still hoping somebody will have a number...

Just got off the phone with a Mopar Tech guy, he said .030" is safe, if it causes interference with that clearance I've got other troubles...

I'm still going for .100"

Sounds like you are pretty close.

I was at the Chrysler Tech Center today but I couldn't find an engineer that would answer the question.;)

When I built my 4.7L stroker out of a 4.0L for my Jeep, I got a high volume oil pump with the kit that had the dual roller timing chain, and some other goodies. Western Engine did the final assembly due to the warantee vs. cost. Throughout that project I got valuable advice from Hesco, and of course Terry from Western Engine.

http://www.hesco.us/customergallery.asp?action=form&formID=1725&record ID=90227

http://www.westernenginesupply.com/

There is also a lot of good information on:

http://www.jeepforum.com/forum/index.php
http://www.jeepstrokers.com/forum/

http://i299.photobucket.com/albums/m...p/STA71238.jpg

http://i299.photobucket.com/albums/m...assembled3.jpg

Good luck...Jeep wave,

4.7 liters? Dangggg..... I would really love to sling some mud with that baby! Torque is FUN!!!! :)

angela

Torque is fun. The Jeep and I have been driving over things for 13 years now.

http://i299.photobucket.com/albums/m...den_part_8.jpg

http://i299.photobucket.com/albums/m...talMasher3.jpg

http://i299.photobucket.com/albums/m...ouse200532.jpg