Went to autozone to get a HV melling oil pump and pick up screen for my 94 z, and they have a few options and i have no clue which one i need. One is 5/8 and one is 3/4. One needed to be used with a certain shaft or what not. Any ideas? Thanks guys

 

I would stay away from the HV oil pumps. Just get a stock volume pump and a high-pressure spring and you'll be set.

 

The HV pump is not need, I would opt for the stock replacement, or the mellings stock type standard volume, if youre a pressure freak then add the white spring that comes with the mellings.

 

It looks like the Melling oem replacement part number is M55, which is a standard volume pump. There is also a M55A which is listed as "Specifically for OEM high performance or special high performance engines", yet it is also standard volume. Does anyone know the difference between the two?

 

If I remember right the A has the larger pick-up diameter. (just buy the pick-up with the pump)

 

Does the diameter matter. 3/4 or 5/8? As long as i get the diameter pickup as the pump right? Or is the diameter size where it meets the motor? Last question....whatz wrong with high volume?

 

Just match your pick-up with the pump, the 3/4 or 5/8s refers to the tube diam of the pick-up.

One of the problems with a HV pump is that it can pump your pan dry and possibly uncover the pick-up for a split second. It also gives you uneven oilpressur eunder throttle, creates more heat. If the pan is baffled properly,deeper (holds more oil) and you have a good windage tray you can reduce the dry pumping or even remove it. But with our frames etc a larger pan sometimes gets in the way. I just used the stock pan with a Milodon windage tray and a stock replacement pump with white spring, anti chatter grooves, and blended passages and rear cap (main).

 

thanks for the help i appreciate it

 

Perry....Do you have part numbers to the items you are running ...thats what I plan on running...Thanks

 

Get the 3/4" inlet pump. HV is not necessary.

 

Here's alittle tech info....

http://www.stockcarracing.com/techar...134_0309_pump/

 

I used the (Summit numbers)
SES-3-60-08-005, it is a Summit gathered package, it includes the mellings standard volume stock replacement pump with screen welded on,pump shaft with steel pinned on sleeve,pump stud nut and washer, and an extra spring for higher pressure if you want it. Its 40.95 $


I then used the Milodon Diamond Stripper Windage tray (have used the sold louvered one with no problems as well)

Diamond stripper - MIL-32250
Solid Louvered - MIL-32100
Windage tray instal kit - MIL-81150 (works for both types of trays)

I modified the pump myself , I ported the exit of the pump into the block and the rear main cap matching, I aslo smoothed out the outlet hole inside the pump case below the gears, then I added some anti chatter grooves (8) to the cover of the pump. You kind of make a cross patter from the center each gear shaft (kinda hard to explain wish I had a link to a picture).

I also had to dimple the pan a little to clear the front most studs that hold the trays in place.

 

How's about this link for that pic and the pump I'd use:
http://www.moroso.com/catalog/catego...?catcode=14444

 

Sorry to wake up an old thread but i just had my oil pump replaced and they put in a Mellings HV pump in. Am i running any risks with the stock pan?

 

No you're fine. Ive been running a mellings HV pump for a few months. Awesome pressure, no problems here. Some people say you run the pan dry,but i know a few guys running the same pump on stock pans.