New oil pump for fresh rebuild?

[jepherz]

I am having my motor rebuilt by BogusSVO anter I had a headgasket fail and let it sit too long. The bottom end was still running but some of the main bearings were worn enough that that was probably the caise of my lower oil pressure according to the gauge.

Am I stupid for trying to reuse the old oil pump after putting all this rebuild money into it or am I safe just measuring the tollerances on the pump and throwing it back on?

Bofus said he has has good luck with enginetech oil pumps. Anyone have opinions on this subject? Recommend a place I buy from? I don't want to use a topline as I have heard too many stories, but I am sure a mitsu stamped pump isn't cheap either... maybe enginetech makes the oem pumps?

 

[GSTwithPSI]

Just take it apart and inspect it. As long as there is no galling in the gear housing, and it's clean, you're good. Take everything apart and make sure there's no sh*t lodged in any of the corners or passages. A bore brush and compressed air work great for this. Then, measure the clearance, make sure they're in spec, pack it with lube, and throw it back together with a stub shaft.

I do prefer the straight cut gears, though. If your pump has the helical version, you can get the gears separately: click

Some people will tell you different gears can't be installed into a foreign housing, but I've never had an issue. Again, so long as the clearances are in spec, you should be good to go.

 

[Yohler]

Quote:
Some people will tell you different gears can't be installed into a foreign housing, but I've never had an issue. Again, so long as the clearances are in spec, you should be good to go.



Interesting. Obviously experience generally trumps most other input, but everything I've read says not to change the gears between cases. The part numbers (I believe) are different and there was a thread on tuners with a copy of the TSB basically stating the same thing. You're not the only one who's gotten away with doing this by any stretch so my question is are you getting lucky, running a reasonable power level to where it's not an issue, or it Mitsubishi making a big deal out of nothing?

 

[GSTwithPSI]

I don't think it's luck. I've compared cases that use each type of gear, and they're identical. If one case was designed a certain way to accommodate a certain type of gear, I could understand how there would be a problem, but that's not the case (at least for the pump housings I've examined).

I'm not saying I know more than Mitsubishi, or that swapping the gears is right or wrong. I just know I've swapped in the straight cut gears into helical cases before, and never had an issue. I have seen multiple issues with the helical cut gears eating housings though, which is why I'm adamant about not using them on my own cars.

The important points are to ensure the pump housing is clean and undamaged, and the tolerances are within spec. So long as those things hold true, I've never had a problem.