You want the melling select std volume pump and install the high pressure spring, I think the part number is 10553.

Send that pan back and get a Champ Pan from JR manufacturing, they are very inexpensive and include a built in windage tray and baffles.

 

i didnt read the thread but i run a trck filter and 6 quarts, i think what they are sayin if you are sucking the pan dry then at all times the pan is 1-1/5 quarts lower as its up in the valve covers in the pushrods and lifters...ive never had a problem except when i only ran 5qt id lose about 40psi at wot, this all with a stock volume

 

its threads like this that are slowing me down on my rebuild....which btw is because of a HV pump and stock pan as well. So basically, an HV pump is not at all needed for typical street use, BUT if you think you must have one, then you should use an aftermarket pan that can hold more oil correct?
I need a new pan anyway, so i'll probably just go with a 6qt pan and a stock volume pump and replace that white spring thing....which I need to look more into

 

Join the "club". My new one has a std. volume/high pressure pump AND an aftermarket pan!

Rich

 

Frank, the windage tray won't be helping if the crank is slapping the oil around

 

This issue is also of concern to me, my block is at the machine shop, and will be ready in about 2 weeks. What part number standard volume pump are you guys using? Whats the part number of the white spring, and where did you get them?

 

I did the stock pump with the white spring and stock pan and I am very pleased.

 

OK..Has anyone that's using a "stock" pump looked at the pump, itself? MOST manufacturers in the country start with the Melling M55 casting! This includes Melling, GM, Moroso, Summit, etc. ALL GM pumps start as the M55 casting, so they have the weaker mounting area. I found that Jegs is now offering pumps in their own brand. Their tech dept. didn't know who the castings are made by, but the pictures don't look like the weak M55 castings. http://www.jegs.com/webapp/wcs/store...34736_-1_10453 ...ALTHOUGH, they do have "55" cast on the side. All M55 castings usually have "M55" cast on them. I've got one ordered, so I can inspect it when I get it.

Frank
CPT

 

Rich, I know you have lost a motor and attribute it to a HV oil pump. I do believe that HV oil pump will cavitate sooner than low volume pumps.
That may be the culprit.

Addressing the point you made about HV pumps robbing Horse power. I politely disagree.
Horse power is robbed by oil pressure not oil volume. So a standard volume and high pressure pump is as much of a hp robber as any other pump that makes high pressure.

I'm still a firm believer that a HV oil pump will work very well in a stock LT1 oil pan as long as the windage tray is retained. (or in other words as long as windage is controlled).

HV pumps serve a purpose and that is to give more oil pressure at low rpm.

Race cars do not need HV oil pumps because they usually pump too much oil at high rpm and the relief circuit cannot keep up and excess pressure is created, (which sucks away power). Also race cars don't idle at 600rpm so they don't need low rpm oil pressure.

Street cars that idle at 600rpm can have 5 or 10psig more oil pressure with the taller gear HV oil pump at the expense of pumping too much at high rpm. It's a trade off.

The amount of oil pumped (or better said, flows) is directly related to pressure, (not volume), so a high pressure pump will pump more oil (when riding the relief circuit). So....that being said, a HV pump and a SV pump with a 70psig relief circuit will pump essentually the same volume and suck a pan dry in essentually the same time. The taller gear HV pump will cavitate sooner than the smaller gear SV pump with low oil supply yes.

So what I'm trying to say is HV pumps are not bad but lack of windage control is bad. Stock oil pans and HV pumps are not bad and HV pumps can be made to work very well in stock oil pans. Moroso is pretty much correct in their response. Windage is very important to control.

I watched one of the best engine builders in the world have oil pressure problems (which could have destroyed a $15,000 motor) using a standard volume oil pump with HP spring. He solved that problem by adding more windage control. He did not blame the pumping problem on the SV HP oil pump. The same problem would have been there if he had used a HV HP pump. It was windage that was his problem. That was the late great Lennart Bergqvist of AUTOSHOP racing engines.

Yet we all do have our opinions and it's good to have a polite disagreement.

Karl Ellwein

 

One of many laws of fluid dynamics (paraphrased) "to move more volume - exert more force. "

Standard volume will be fine with precautions(ie..white spring, knock to cover off and check clearances) The offered 'blue-printed' pumps are usually spot on with their clearances. Careful with high pressure too. As already stated, some of these offerings work best with certain bearing clearances. The chief machinist at my machine shop of choice prefers more bearing clearance on his race engines, therefore he uses HV pumps. On his S/C apps. he uses higher pressure to compensate for the bearing loads. On stock or mostly street driven N/A apps, stock pressure/volume but verifies pump condition and quality prior to install. He says 1 in 10 needs work out of the box.

Good luck!

 

High volume pumps take more hp to spin at any pressure. They will flow more and make more pressure (and take more power) at a given rpm until the bypass opens. When the pressure at which the bypass opens is exceeded, the excess volume is still being pumped, it is just reurned to the pan. Kind of an internal leak. You don't any increase pressure, but the pump is still moving the oil.

Rich

 

that is very true. The hp is slight though.

On the contrary, a standard volume high pressure pump 70psi) will take more hp to turn than a high volume regular pressure (45psi) pump. That's the point I was trying to make.