Helical or Straight cut oil gears?

[DSM_Zak]

I'm doing a motor build and after buying my new OEM oil pump I realized my old gears are straight cut on my 6-Bolt that was swapped into my 94 1GB from the previos owner. But the new gears I bought from JNZ tuning are Helical cut.

I've heard the helical cut gears are not as good, and some people never use them. Only straight cut gears.

Well, Ive also herd the helicals are fine, just a newer design and quieter.

I'm not putting this motor together with helical cut gears, and having something go wrong. The car will be pushing 350HP with an evo fuel system and meth.

Thanks for the help in advance!

-Zak

Anyone?

Hmm, any other takers before I slap this thing onto the block?

ehh, its a go, going to finish the bottom end tomarrow.


please feel free to add more insight!

 

[perley03]

The helical ones are a revised set of gears. They have more surface area on them, allowing for more oil to be flowed at the same rpm than the straight cut gears.
I know in my 90 GST it had straight cut, and my 95 GST had the helical ones. In the 95 I was pushing more power than the 90 and I had no trouble with the helical ones.

 

[relmer4]

In 11/92 Mitsubishi released a tsb outllining the change in oil pump gears from straight to helical cut. They recommended them also for customer concerns of high pitched whining from the engine. From what I can tell this was only for the 6 bolt motors. According to the tsb all mitsubishi engines built from 6/11/91 were assembled from the factory with the helical pump. I switched to a helical cut when I rebuilt my engine and there are no oil problems. Hope this helps.

 

[xxxbulletzxxx]

im a straight cut kinda guy.. more durable.. so what, a little bit noisier? what happens when you do a b/s removal with prothane mounts? same difference

 

[Defiant]

Straight-cut gears are noisier and cheaper. Helical gears are quieter, stronger and introduce end-thrust to the system. If the teeth are the same cross-section, the volume they pump will remain the same.

 

[DSM_Zak]

Helical it is.
no B/S and Prothanes are already in the car haha, quieter oil pump still helps!

 

[spadepro22]

Bringing this back. Should I go back with helical or straight cut in a 1g 7 bolt with b/s delete and poly mounts?

 

[ibreakmytsi]

I have straight cut gears in my build. I can't hear any oil pump wine. And I'm pushing 400
Crank horsepower. 5k on the engine now