273 Commando Rebuild Oil Pump Selection?

[Bossanova5]

Just got the engine back in pieces from the machine shop.
The owner of the shop (Been in business since the 80's) didn't think it necessary to put a Melling high volume oil pump in the engine.
The engine is a just a stock rebuild.
Should I put a high-volume Melling oil pump in the engine or stick with just a regular Melling replacement?
Thanks

 

[junkyardhero]

i put melling HV pumps into everything i build, stock or otherwise.

right or wrong, the only thing i know is that i haven't lost a motor because of it.

 

[Plymouth 65]

I agree, all my builds get high volume pumps. 65

 

[Oldmanmopar]

The issue with a high volume pump is you should run a hardened oil pump drive shaft. It takes a lot more force to turn the HV pump.

I do know the HV pump will chew up a roller cam bronze gear style quicker. Especially with heavier race oil on start up. If you have the pan down on a engine with high mileage HV pump is a plus. Not alway the case with fresh builds.

O

 

[Dartswinger70]

Id be concerned with pressure over volume of the stock pump performs well engine hot at the correct pressure etc. if it isnt a race build it may be ok with a stock style pump. I had heard high volume can pump all the oil to the top quick so you may need a large sump pan? think of high rpm racing etc. ihave used both on my next build I picked up a stock style pump I am not partial to either like said just as long as it has good oil pressure etc. Also if I remember what I have been taught as long as bearing clearances are correct oil pressure should fall within spec etc.

 

[4spdragtop]

We went std volume, BUT i added a MP high psi spring kit.
**edit** 70 psi driving, 40 idle

 

[JDMopar]

If (and he probably did) get your bearing clearances set properly, there's no need for a HV pump. My machinist is 82 years old and has put MANY top name NASCAR drivers in the winners circle with his engines. He told me not to put a HV pump in my 273. When we put it on the dyno, it had great oil pressure and plenty of volume.

 

[Gomer Pyle]

I use a stock 361 2 barrel pump in my Max Wedge race car, about 55-60 lbs through the traps at 7,100. No need for a Melling and if you do use a new Melling make sure it gets disassembled first as they sometimes come with machining grit in them from the factory and will ruin your new rebuild within minutes. I spoke with Matt Steen about his 273 powered NHRA super stocker that goes through the traps about 8K and he said other pan, pickup etc. it's mostly the stock oiling system.

 

[toolmanmike]

I spoke with Matt Steen about his 273 powered NHRA super stocker that goes through the traps about 8K and he said other pan, pickup etc. it's mostly the stock oiling system.

Amazing

 

[junkyardhero]

I spoke with Matt Steen about his 273 powered NHRA super stocker that goes through the traps about 8K and he said other pan, pickup etc. it's mostly the stock oiling system.

"mostly stock" from a racer means highly modified and packed full of black majick with a side of dark arts.

 

[Gomer Pyle]

"mostly stock" from a racer means highly modified and packed full of black majick with a side of dark arts.

In the case of heads, manis, valve train and such yes but in Super Stock you can run some pretty exotic stuff in the oiling dept and I've spoken to him a few times at length and he's pretty much a straight shooter IMO.

 

[Demonracer]

Don't run the high pressure pump on a normal street engine, the HV pump is fine, I too only run the HV pumps in everything.

 

[jeff alder]

273's are virtually indestructible with normal proper maintenance and a stock oil pump.

 

[4spdragtop]

Agreed, that can be said for most if not all Mopar engines.

273's are virtually indestructible with normal proper maintenance and a stock oil pump.

 

[Bossanova5]

What is an HV pump?

 

[toolmanmike]

What is an HV pump?

high volume. It usually has bigger gears.

 

[Demonracer]

TMM, not necessarily bigger gears, they are taller top to bottom.