Oil pump difference

[Tatback]

I finally got the engine pulled out of the Chrysler today and decided to take off the oil pump to maybe use it in place of the "new" one that came with the new engine. After taking them apart to make sure they were clean I noticed some differences inside. Mainly the holes around the impeller are quite different in size. Would using the larger holes give me better oil flow and pressure?

Here is my original oil pump

And the new pump

And together

[Tatback]

I should add... The one with the larger holes came out of an engine with a partial flow set up. The smaller one came out of my set up with full flow. I am changing the new block over to full flow too.

[JBNeal]

the larger openings would allow for more flow which can boost filtration rate and heat transfer...I think the gauge pressure would drop slightly at low RPMs but the increased flow would offset this; pressure at higher RPMs I believe would still be regulated as with the original pump

[dpollo]

Regardless of the holes, I would use the pump which shows the least wear.

[jeffsunzeri]

The pump with the larger holes is referred to as a "High Volume" pump. It does just what its name implies, delivers a higher, or larger volume (gallons per minute) flow rate. I've never seen comparative numbers, but have installed both and any difference is not noticeable in oil pressure or running temperature. I suspect it may improve bearing longevity, but who knows.

Edited December 17, 2015 by jeffsunzeri