replace oil pump
My last motor died because oil pump failed.
if yes
What should i get?
made by melling
i have seen a few diffrent types
1. one is high (15-25psi over stock) psi and (25%)volume
2. just high volume 25%
3 high psi 15 - 25 psi over stock
someones reply on another forum
Ok, oil pressure is not created by the pump directly. It is created by the clearances on your bearings. IE looser bearings cause lower pressure. Now, what keeps your oil pressure from going up forever is one of two things. The pump relieve valve opens or the characteristics of the pump itself become a restriction much like a set of stock heads with a aftermarket cam. With a high volume pump basically all it does is just push more oil through the system and the oil pressure relief valve opens at the same PSI as stock. A high pressure pump is a waste because a motor only needs about 10 psi of oil pressure per 1000 rpms to be properly fed. Just go with high volume and you'll be ok.
someones reply on another forum
Ok, oil pressure is not created by the pump directly. It is created by the clearances on your bearings. IE looser bearings cause lower pressure. Now, what keeps your oil pressure from going up forever is one of two things. The pump relieve valve opens or the characteristics of the pump itself become a restriction much like a set of stock heads with a aftermarket cam. With a high volume pump basically all it does is just push more oil through the system and the oil pressure relief valve opens at the same PSI as stock. A high pressure pump is a waste because a motor only needs about 10 psi of oil pressure per 1000 rpms to be properly fed. Just go with high volume and you'll be ok.
IMO from what I've read high volumes aren't needed. They can be used just fine with a stock pan, as long as you're still using the windage tray. I'm going to be replacing mine soon because the oil pan gasket is leaking and I figured what the heck. I was recmmended to use the canton "high" pressure spring (I think 10-12psi) over stock. I need to get my mechanical test gauge finished so I can see if my autometer oil pressure guage is lying to me.
Matt
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Guys have also had issues with the increased load on the oilpump drive damaging the gear.
While crying for proof why don't you show me one shred of evidence that shows it is anything but a waste of money and HP.
The stock LT1 pump is a step above the old smallblock pumps anyway so even if an old gen1 stocker was crap that does not apply here, neither does any other make or model.
Tell you what when I put my Briggs & Stratton together all it needed was slinger, no pump atall so all this talk of pumps in a totally different engine must be silly anyway since that engine doesn't need one no engines need them
. That is about the depth of the logic you offered
Go look up at a parts store, they both call for a melling part#M55 (I run a parts store I sell a dozen a week).
Second, this ******* topic has been beaten to death on chevytalk.com and guys who build 800hp big blocks will agree that unless you are turning extreme rpm's for extended periods of time you will not suck a pan dry if the pump is installed properly and the pick up is installed properly.
I'll stick to my experience versus your so called "knowledge" from the net..
Though if you are ******* **** about it you can run a STOCK Big Block pump on a smallblock using the high volume smallblock (5/8" or 3/4 I can't remember) pickup screen.
And if a high volume pump is "stealing hp" from your engine enough for you to worry about your engine must suck ***** anyways and I would be worrying more about other things than the friggen oil pump.
Guys have also had issues with the increased load on the oilpump drive damaging the gear.
While crying for proof why don't you show me one shred of evidence that shows it is anything but a waste of money and HP.
The stock LT1 pump is a step above the old smallblock pumps anyway so even if an old gen1 stocker was crap that does not apply here, neither does any other make or model.
Tell you what when I put my Briggs & Stratton together all it needed was slinger, no pump atall so all this talk of pumps in a totally different engine must be silly anyway since that engine doesn't need one no engines need them
. That is about the depth of the logic you offered 
You run a parts store is your claim to knowledge
thank you again. How many here have actually met a parts store person they would call genuinely an expert in any particular model, occassionally you will meet a "jack of all trades master of none" but usually I wouldn't trust those guys to change a lightbulb. Like the guy who told me I needed a Lingenfelter intake and bigger injectors on my stock Caprice
. Few true gearheads are capable of dealing with the ignorance of the average parts store customer, it drives them wild and they get out. I will let my 5 ASE Certifications speak to my ability and knowledge..Wheres yours?
ENGINE PERFORMANCE
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4+ years of Gm Dealership experience
6+ Years in the parts business
You run a parts store is your claim to knowledge
thank you again. How many here have actually met a parts store person they would call genuinely an expert in any particular model, occassionally you will meet a "jack of all trades master of none" but usually I wouldn't trust those guys to change a lightbulb. Like the guy who told me I needed a Lingenfelter intake and bigger injectors on my stock Caprice
. Few true gearheads are capable of dealing with the ignorance of the average parts store customer, it drives them wild and they get out.Last edited by 383LT1S10; Feb 12, 2006 at 09:53 PM.
Still though I would like to see a case where a HV pump was actually shown to be of any help on a shortblock with stock like clearances. If the builder sets it up for a HV pump with loose bearings them you have little choice.




