I'm reading all kinds of things about the M55HV pump sucking the oil pan completely dry and ruining a good motor. I've just about finished rebuilding an L98 and this pump is what was provided in the Sealed Power rebuild kit. Reusing the old one is completely out of the question as it no doubt has metal shavings from the destroyed old bearings in it.

Am I better off getting a standard volume pump put the screen in and use a metal aftermarket sleeved shaft? Don't want to seal up the bottom til I have an answer here. I have an LT1 cam in the motor to replace the ruined original. But otherwise its a factory motor. Thanks guys. I'm hoping to get this in the car this weekend so a quick answer would be appreciated. I've searched but every thread seems to dissolve into an argument with no clear answer. Street car only.

 

No need for a HV pump really. I run a standard vol and PSI pump in my car and I spin it to 8k rpm all the time.

 

Thats been the general census online. I've read even strokers don't need it..... I'll swap it out. I know I can find standard volume Melling pumps at the local Advance store.

 

Make sure you get the thicker neck version of the pump. Do some research on that..

 

This is what I have now that came with the engine kit...

http://www.summitracing.com/parts/SLP-224-4143/

Sealed Power has M55HV cast into it. I'm guessing it was reboxed Melling....or just a casting, says the pressure is standard but high volume.

 

Needed volume, from pump / pan, depends on your bearing clearances. .0020"-0.0025" is best, and doesn't need HV. If you're closer to 0.0035" then you'll need the HV.

 

I had .0020. Right where the machinist said I would be, he told me anything between .0015 and .0030 is acceptable and told me based on his checks of my crank and etc I should be right about the .002 and I was. I'll see if I can get the standard pump from the local store. Yes I will make sure I don't have the thin casting, I've seen the pictures. Guess that means I won't need the steel sleeve either. Since I have a factory stock rebuild save for the cam I guess I'm good with the plastic sleeve. Thanks guys.

 

I run the HV on my 383 with no problems, idles@60psi, my builder cut the spring some, how much did he cut off? never crossed my mind to ask.
I'll call him to find out. Will post for those interested.

 

alll those pumps are now thin castings, do not use them on anything with solid or even poly engine/tras mounts. and specially on anything that is raced or launched hard.

the new style pumps used to come with a aring sheet inside the box dont know if they still do.


u want to use a melling m-select pump these are the same pumps but they use the original heavy casting, not the new lightwieght thin crap that breaks

be aware the thick case pumps are also 2-3x more money now

 

Lower RPM and stock pan you will be fine. Stock pan and some RPMs and you wont be.
The HV does take a bit more hp to spin and IF your running a polly dizzy gear its not good either