Hemi oil pumps

Is there any risk of pumping the pan dry by using a hi volume small block dodge oil pump in place of the original in a 270 dodge hemi? Should I just rebuild the stock pump? I'll be using a stock valvetrain setup and windage tray.

 

The HV smallblock pump probably won't push that much more oil than the stock 270 oil pump. Measure and post the 270 pump outer rotor (OD & thickness) before making any decisions...

 

I had a 340 pump on my 392. Ran it at full throttle at Bonneville without pumping the pan dry. I had restricters to the rockers.

 

I'd rebuild the stock one. You'll have to modify the oil pan for the 340 pump with adaptor, as it doesn't fit in a stock pan. Also the windage tray bob sells doesn't fit either.

 

I am using an adaptor with a 340 oil pump and a milodon pick up in my 392 AA/FD engine.Same crank after 100 plus runs. I do have a special aftermarket dragster style pan so I can not relate to clearance problems with the stock pan. I have used stock pumps with equal success. Pay attention to the oil filter bypass valve in the engine block. Can be set up for full flow or partial. Goldy

 

The high deck Hemis, Chr, Dodge, DeSoto all use the same pump. The 340HV pump only pushes 3.5% more oil than the OEM. I haven't seen any numbers for the low deck Hemis. On those there is a different part# for each brand. Anyone got flow numbers for the low decks?

 

Yes, I had to put a blister in my pan (early 331 pan, rear sump) to clear the 340 pump and use the Milodon adapter on my 392.

 

Thanks for the response guys, and the heads up on the windage tray. I'll be rebuilding my stock pump.

 

Hi Desoto Hemi experts.
you have a look at the attached photos, the first one is the stock pump out of my 330 Desoto the next one is a new pump that came with the motor. And the third is the two together. The new pump is a different shape and would require a new pick up but will bold up to the motor. From initial measurements it would need about 3 mill taken off the mounting surface to totally engage the drive dogs.
Is this possible or am I heading for disaster? I see you can buy replacement pumps for Chrysler but everyone only sells rebuild kits for Desoto. It it this simple or have I missed something?
Next question is the oil bypass valve, my motor does not appear to be fitted with the bypass valve as referenced in the Tex Smith hemi book. Did some of these motors come out without the bypass valve? Or am I mistaken? I have inserted a rod in the oil pressure hole at the top of the block and tried to tap the valve out but it is a solid bung in the block when hitting the rod the block rings. I have checked out the oil flow and it appears it is total flow through the filter. any thoughts or suggestions

 

All OEM pumps now available are rebuilt, not new unless you happen to find a NOS somewhere. Leo's book shows 2 part numbers for high deck Hemis Chr, Dodge & DeSoto. So a rebuilt 392 pump should work on a 330. There might be a difference between the rear sump pump & (certainly) the pick up vs a rear sump., might be why there are 2 part numbers.

 

Thanks George, I spent a few hours searching and believe the new or rebuilt pump I have is from a centre sump motor. It is somewhat shorter than the original pump. Are you suggesting it is a 392 pump?
From what I can gather the Desoto is full flow through the filter.
Cheers
Peter

 

As said, the HV 340 puts out the same volume as the stock 392. Melling did a flow test years ago. Why mess with adapters and odd ball intermediate shafts?? The DeSoto pump in the picture is the same as a 354 Chrysler. The 392 style pump was also used on 315-325 Dodge. If you want to use the 392 pump in a rear sump pan then a new pickup tube and screen is needed. A pickup tube assembly for a late Dodge pickup truck, LA type small block, fits all of the requirements except for being too deep into the pan. Make it shorter.

 

Where the same part number was used on all three brands, you could say it's a 392 or 330 or 325 pump.

 

What everyone has failed to mention is that there are two different mounting flange bolt patterns with the screw in pick-up style pumps. The 392 pattern (also late 354 truck) is different than all the rest of the Chrysler, Dodge, and Desoto.
(This is why one bolt hole on the adapter plate of the converted 340 pumps is slotted)

 

Technecly speaking, there is an insignificant 3.5% improvement with the 340HV pump. The HH site claims a 30% improvement, & so did Doc Fromader on his 315 build on Webrodder. I sent an inquiry to Bob & Doc about the claim. Doc said that it is a theoretical 30%. Seems there are no new OEM pumps available, just rebuilt. From what he was saying when the pump is rebuilt they replace the impellers, but they don't weld up any erosion of the housing, resulting in less volume, possibly up to 30%. If you go 240HV you get full volume, plus if your oil pump craps out & you notice it before any damage occurs, you can find the 340 pump easily.

 

...Respectfully disagree about the 392 pump being different from all others. There are two (2) mounting pad designs, 51-54 and 55-58.
The 392 'style' pump was also used on Dodges and DeSotos, different part numbers, same pumps.
If you worry about pump failure try keeping clean oil in the engine.

 

38 mopar fan

If you go to hothemiheads.com they only deal with early hemis on that sight.
They are very knowledgable and can give the answers you desire.

 

Well I’m not positive what pump I have but I think it is from a centre or front sump installation.
Measured it up and took 60thou off the pump mount surface to get the drive at the same height as the pump that was fitted to the Desoto. Cutting down a 318 pickup to match everything up. Will get some better photos this weekend