Moparts

New big block oil pump problem

Posted By: 1970RT

New big block oil pump problem - 10/04/14 05:24 PM

I have my 440 in a shop being rebuilt and a problem has come up. The engine is on a stand just about ready to get put back in the car. I provided them with a new oil pump and when they hooked a drill motor to the oil pump drive to prime the motor, the bottom of the oil filter bellied out and the seal blew spraying new break-in oil everywhere. They are telling me the pump is bad (too much pressure) and that I need to provide another one. The pump is a Mopar Performance P4286590. I'd like to know what the heck went wrong as I am going to be out about $100 for the pump as I bought it several years ago and can't exchange it. Has anyone had experience with a situation like this before?
Posted By: Pacnorthcuda

Re: New big block oil pump problem - 10/04/14 05:27 PM

Sounds like Ike the pressure relief valve is stuck closed. I would take it apart and inspect, might be a easy fix.

What brand of oil filter was it that failed???
Posted By: jamesc

Re: New big block oil pump problem - 10/04/14 07:27 PM

no new oil pump should be installed without being disassembled and cleaned.

pull the pump, clean it and free the pressure relief valve that is stuck closed.

next time put a gauge on the engine and see exactly what the oil pressure is.
Posted By: Twostick

Re: New big block oil pump problem - 10/04/14 07:29 PM

Good luck with that engine if that "builder" can't figure out what happened there and how to fix it.

Pull the pump apart and clean everything up. Don't be surprised if you find metal from the manufacturing process in it. Make sure the relief valve moves smoothly in its bore. Check the spring to see if somebody put extra shims under it. If it's shimmed, remove them to lower the pressure. You can get a lower pressure spring from Mancini if you don't find that the valve is stuck closed for what ever reason. They also sell an adjustable pressure kit for it too.

Kevin
Posted By: Mopar Guy

Re: New big block oil pump problem - 10/04/14 11:37 PM

I agree whit what al is saying that the presiure valve is probably stuck in the pump Why use a HV oil pump when they are pumping more oil that the engine needs if you are usesing half grove main bearings i will not use that pump any more as it eats up hp and can break the drive shaft if you are unlucky and use thick oil and fill up the heads whit oil that in many cases result in emptying the oil pans on oil if you run it on the strip a pro built engine that is used for street&strip never needs more than about 55-60 psi of oil presiure that melling set there std pumps to and that pump will give you atleast 80 psi that should be corekted by triming the spring for the valve that not so many do even in these day´s becas it can do more harm IMO
Posted By: sr4440

Re: New big block oil pump problem - 10/05/14 01:59 AM

yep the presiure valve is probably stuck, but my 1st thought "how big was that drill?"


Joe
Posted By: 1970RT

Re: New big block oil pump problem - 10/05/14 02:31 AM

Quote:

What brand of oil filter was it that failed???



It was a Microgard filter.

Quote:

no new oil pump should be installed without being disassembled and cleaned.



I talked to the engine builder and he said he did take it apart and everything looked fine, no metal shavings and nothing was stuck.

Quote:

yep the pressure valve is probably stuck, but my 1st thought "how big was that drill?"



Not sure of the drill motor output but it was a big drill.
Posted By: jamesc

Re: New big block oil pump problem - 10/05/14 04:15 AM

Quote:

I talked to the engine builder and he said he did take it apart and everything looked fine, no metal shavings and nothing was stuck.




two most likely possibilities

1st: he lied
2nd: he doesn't know a stuck PRV when he sees it

this isn't rocket science. either the PRV is set ungodly high (not likely) or it's stuck closed

anything outside of that is remote at best

disassemble the pump entirely (EVERY piece), clean it, reassemble it making sure the PRV shuttle is free, install it, install a known accurate pressure gauge and try it again.

i once installed the PRV spring cup plug backwards in a 340 oil pump.

yea when i primed it it buried a 150# gauge and blew up the oil filter like a balloon.

i screwed up, humans do that
Posted By: NTOLERANCE

Re: New big block oil pump problem - 10/05/14 03:52 PM

Quote:

Quote:

I talked to the engine builder and he said he did take it apart and everything looked fine, no metal shavings and nothing was stuck.




two most likely possibilities
A
1st: he lied
2nd: he doesn't know a stuck PRV when he sees one



It could be freed up now as well
Take him a stock working pump and look at the new one your self.
Posted By: JohnRR

Re: New big block oil pump problem - 10/05/14 11:20 PM

Quote:

yep the presiure valve is probably stuck, but my 1st thought "how big was that drill?"


Joe



Size of the drill wouldn't matter , the engine is going to spin the pump faster than a drill will , it's the pump valve and/or the filter.

As far as returning the MP pump ... good luck , MP doesn't warranty performance parts, they don't even garuntee they will fit the intended application ... stage 6 heads anyone ???
Posted By: 440Jim

Re: New big block oil pump problem - 10/07/14 06:42 PM

After making sure the relief valve is not stuck, by removing the spring and using a magnet to slide the valve out/in, then use a known pressure spring from another pump. Sometimes the spring supplied goes to 100 psi and some filters don't like that high a pressure.

I have been using the same old spring for many years in different pumps after I trimmed it to give me 70 psi going down the track with the engine warm.

If you or a local Mopar guy doesn't have an old pump spring, let me know and I can hook you up with a old stock spring that should be around 50-60 psi and a 1/8" spring spacer to get it around 60-70 psi with warm oil at 3000 rpm or more. Cold oil pressure at lower rpm depends on too many things like oil viscosity, bearing clearances, rpm, etc.
Posted By: sc301v

Re: New big block oil pump problem - 10/07/14 08:25 PM

A microgaurd filter is also made by fram...They won't take an extra pressure either.
Posted By: Challenger 1

Re: New big block oil pump problem - 10/07/14 10:29 PM

Quote:

I agree whit what al is saying that the presiure valve is probably stuck in the pump Why use a HV oil pump when they are pumping more oil that the engine needs if you are usesing half grove main bearings i will not use that pump any more as it eats up hp and can break the drive shaft if you are unlucky and use thick oil and fill up the heads whit oil that in many cases result in emptying the oil pans on oil if you run it on the strip a pro built engine that is used for street&strip never needs more than about 55-60 psi of oil presiure that melling set there std pumps to and that pump will give you atleast 80 psi that should be corekted by triming the spring for the valve that not so many do even in these day´s becas it can do more harm IMO





HV pump is more trouble than they are worth.
Posted By: Cab_Burge

Re: New big block oil pump problem - 10/08/14 06:04 AM

I put a new bracket race motor together for a freind and customer, it has a new High Volume Mellings or Speed Pro pump, CRS which one I was trying to prime it this afternoon and it wouldn't prime until I loosened the Wix oil filter and burp the air ouf of it That has never happen to me in the past I was using a half inch drive reversible Black and Decker drill motor that I have used for years, I did fill the Wix oil filter up first before putting it on the motor, I put 10x30 wt Valvoline straight non synthetic oil in it, I usually use 5W20Wt Valvoline in most of the motors I build like this but I decided to use the 10x30 instead this time It does have narrow full groove main bearings and race rod bearings with a little over .0028 for clearances and the mains have a little over .0035 I haven't shorten the bypass spring yet,it had 70 lbs on the drill motor I'll wait to see how much pressure it has with hot oil on the dyno and go from there
Posted By: 440Jim

Re: New big block oil pump problem - 10/09/14 01:55 AM

I have used Wix 51515 filters for break-in on every motor I have built in the last 15 years with no problems. My current motor has the same and the prime pressure is fine (at the main bearings). I have normally used straight 30W oil for break-in, but this roller cam motor has 10W-30 oil and the prime was fine.

I do use the less restrictive 51515R filter during racing.
Posted By: Dyno1

Re: New big block oil pump problem - 10/09/14 02:26 AM

I have had to burp the filter two or three times in the past with a remote filter set up. No problems after that.
© 2024 Moparts Forums