6 bolt oil pump - best one?

[billk1]

Looking for some current info on what is a good oil pump to run with, i'm building a 6 bolt 2.3 motor for street use and i've read that oem mitsu pumps arent what they used to be, they are made by the aftermarket so why not just go with an aftermarket pump? I've heard horror stories of those and i've heard good things too, Are Hyundia oem pumps an option or or are they made by the aftermarket, just want to know whats best to buy today, aftermarket case?, oem gears? whatever I get I will still go thru and check clearences and deburr gears etc...

 

[dsmusmc]

Mitsubishi OEM has been proven time after time. Unless you have $5k+ for a dry sump setup.

 

[joescool2008]

I've read the straight cut gear ones are stronger and less prone to wear, I'm pretty sure that would be like 90/91 style. They do make more noise however.

 

[Hal]

Keep reading (since it's all been beat to death before) and you'll find out why the helical gear set is the one you should use.

It has nothing to do with strength or noise.

Hal

 

[ty92dsm]

Can't go wrong with OEM

 

[HIGHPSI4]

Keep reading (since it's all been beat to death before) and you'll find out why the helical gear set is the one you should use.

It has nothing to do with strength or noise.

Hal

Yep, search a little and you will find all kinds of information.

 

[Deadspool]

Keep reading (since it's all been beat to death before) and you'll find out why the helical gear set is the one you should use.

It has nothing to do with strength or noise.

Hal

Helical if retaining the balance shafts. Straight cut if not.

the helical gear will fail to thrust load at high rpm if using the stub shaft. Which basically everyone with a 2.3 is using.

 

[Hal]

Helical if retaining the balance shafts. Straight cut if not.

the helical gear will fail to thrust load at high rpm if using the stub shaft. Which basically everyone with a 2.3 is using.

The balance shaft (or lack there of) has nothing to with the thrust loading.

Hal

 

[DROPthatCLUTCH]

I bought new helicals, then got rid of them for some straights.. Reason for me was the helicals will cause more wear on the inside of the front case(which is aluminum) than the straights will. But I do remember those helly's spun awfully smooth while the were in the front case compared to the straights. Either way you go, you should be fine if installed correct and your timing belt torqued/tensions correct.

Also keep in mind that a normal helical gear will use a bearing, whereas, it doesn't in our front case, the case itself is technically the bearing. Helicals tend to want to "slide off" one another creating a side load on the bearing surface I.e., the front case. Now which one do you think will last longer?

And again, either way you go make sure you tension the timing belt to spec correctly. Especially with a stubby shaft.

 

[Hal]

The front cases have different part numbers (there's even a TSB on it).

Straight cuts use one part number, helical another.

Mix and match at your own peril.

Hal

 

[Street Surgeon]

IIRC you can't even get the straight cut gear cases anymore

 

[94allwheeldsm]

I just got my SIM 2.3 with brand new OEM oil pump, which by the way doesn't come with the gears, so I ordered a set of the straight cut gears from Extreme. Could you please elaborate on the different case numbers and why its suggested to not mix the gears. I do not want this motor going anywhere for at least 30,000 miles!


*EDIT*
I have been doing some quick research on this subject. I found a couple people who have put the straight cut gears in a helical case and have had no issues. I couldn't find anybody saying that it caused a motor failure. If anyone has some stories I am all ears

From what else I could find the helical case has some minor differences on the surface where the gears ride that has to do with clearances between the case and gears.