The melling HV I put in gave me 65psi with a drill.
No oil to top end
- Thread starter wes beem
- Start date
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Swinger 340
Well-Known Member
I see no reason to have a HV oil pump for that motor. I would recommend a deep sump pan when using such a pump. Also a possibility of oil leaks at valve covers and other sealing areas. I believe you said the motor came out of a truck. They had the extra Quart pans but the pan will not fit into a car. You will need to get another pan and pickup if using for a car. It will fit a van.
YIKES
Newbomb Turk
Well-Known Member
Why a deep pan with a HV pump. The lie of sucking the pan dry was exposed decades ago.
Swinger 340
Well-Known Member
Commination of HV pump drawing extra oil from the pan to the upper part of the motor and what oil is left in the pan sloshing away from the pick-up, while you are doing a wheelie in your grandma's station wagon. LOL You could be correct on your comment. I am referring to ancient recommendations. I do have a deep sump in my 340 Van but I also have one in my stock 69' 340 Dart, as in my photo. Never had an issue with either one. Have not yet done a wheel stand in the Dart.
Rapid Robert
Well-Known Member
any thoughts on what was wrong with the 2pumps (pressure relief valve issue??) EDIT gear to pump cover clearance?? After what you have been thru on this I would HAVE to know. RR
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Dunno but ive been talking to folks i know about it and so far one guy has said he went through 6 fuel pumps, another giy went through 4 headlight switches, and another guys burned through 3 dimmer switches....i guess these new parts just have no QC and are trahs now....ill be grabbing everything i see at the local junkyards now.
I've been messin around with cars professionally and as a hobby since 1974 and have never seen or gotten one single bad new oil pump. Not one.
and 2 in a row sounds extremely unlikely. There is something else going on.
Newbomb Turk
Well-Known Member
I’ve had one. It’s the one that was incorrectly machined on the mounting pad and it hit the CW on the crank.
Thinking about it, I can’t remember if the CW’s on a 360 are larger than a 340. That pump may not hit on a 273-318-340 CW.
16richard
Well-Known Member
My money would be on the gauge(s).
I've run HV pumps in all my engines for 4 decades... Daily drivers and NEVER ONCE ran the stock oil pan dry...
And all Melling oil pumps come with the high pressure spring to give 72 psi give or take... 65 psi is right in the ball park there...
I had a new TRW pump fail once at 500 miles... The pressure relief valve got stuck...
According to their "lab": Due to small tiny minute particles small enough to fit through the stock pick-up screen... If their pump can't handle what the pickup screen can't catch, it's a piece of junk to me...
However, they rebuilt my failed pump for free and sent it back to me, but refused to compensate me for my expense to fix it... They accused me of tampering with it because we removed the cover to diagnose the failure (how else are we supposed to figure it out???)...
I sold that pump to someone locally for $25 and warned them about what happened to me... I refused to run another TRW oil pump after that...
....and that's a FACT.
It's not all that uncommon to have a bypass stick. Usually it is caused by debris between the bypass valve and the bore in the housing as this is a close tolerance. It doesn't take much as far as particle size to make it stick. Sometimes you will nitice the bypass valve sticking before you notice that a cam lobe is going.
Pump inlet screens are not designed to filter out small particles capable of sticking a bypass. It is the job of the filter to remove these small particles from the system. Unfortunately these particles have to pass through the pump first to get to the filter. That's just how the system works. If you put a filter or screen fine enough to remove those particles on the inlet side of the pump it would be too restrictive and the pump would not pump oil. The screen on the inlet side of the pump is intended just to keep out the big chunks that could lock up the pump.
Pump inlet screens are not designed to filter out small particles capable of sticking a bypass. It is the job of the filter to remove these small particles from the system. Unfortunately these particles have to pass through the pump first to get to the filter. That's just how the system works. If you put a filter or screen fine enough to remove those particles on the inlet side of the pump it would be too restrictive and the pump would not pump oil. The screen on the inlet side of the pump is intended just to keep out the big chunks that could lock up the pump.
I don't consider a sticking bypass valve a "failure" of the oil pump, simply because an oil pump should be completely disassembled and inspected and clearanced if desired, before installation. To me, that's just a normal part of a build. So a stuck relief valve would be caught and dealt with then. I do agree with Karl though that if an oil pump cannot handle the debris that's small enough to come through the pickup screen, then it's a POS. I always use Oil pumps that are made in USA. If you've ever seen an import knockoff, then you know there's a difference.
I agree, it's not the pumps fault. Even if the pump and bypass valve are properly cleaned and clearanced on assembly, debris can be shed during breakin, when a part is failing or wearing or if the engine is opened up to be worked on. None of the pumps foreign or domestic are designed to keep small debris out of the pump. On rare occasions this can cause the valve to stick. Look at the size of the holes in the screen. It's a coarse strainer not a filter. I have seen the best pumps stick a properly clearanced bypass valve. For better or worse It's how the oiling system has been designed for years.
That's all you really need, running a HV pump is a waste without oil mods.
The slant 6 in Vixen idles hot between 70-75 PSI. Stock oil pump with the high pressure sprAng. Works real good.
So the 2 in a row brand new ones didn't work but when an old one was put in it works fine but something else is going on?
Y'all got stock in these Chinese parts companies or what?
People allover the place are running into these issues with car parts across all brands. The Junk has finally hit our shores.
Ill be using NOS or junkyard parts from here on out until they start making stuff In America again.
I bought a parts car that had a 360 in it. It had broken the oil pump drive and lost oil pressure. The owner stopped before damage to the rest of the engine. I tore it down and opened up the oil pump. One of the lock wire springs had come out of a lifter and was jammed up in the rotor of the pump. The engine had the stock oil pickup so stuff can get by that is big enough to mess up a pump.
MopaR&D
Nerd Member
It's just strange how that could happen based on how oil pumps work. If they're built crappy they might not pump as well as higher-quality ones or maybe wear out prematurely but being completely unable to pump at all doesn't really make sense. It's something that's easy to check as well, not many parts to it. I have an SA-Design book, How to Rebuild Small-Block Mopar that was published over 10 years ago and even then the author strongly recommended to always pull the cover off of a new pump to check the internals and measure clearances before bolting it onto the engine.
Maybe it was something as simple as the relief valve being stuck open from debris which you could have found and fixed by taking it apart, cleaning it and putting it back together. If it was full of metal shavings from manufacturing maybe you inadvertently pumped some of that junk into your engine while running the starter for 10 minutes.
Swinger 340
Well-Known Member
Maybe I'm off here a little but every time I got back a block from the machine shop, I always washed them out with soap and water and gave them a good rinse with clean water and blow air dry. Clean out openings with special brushes. Can't always blame the machine shop. That a good reason to "Hot Tank" your blocks before assembling. Never can be to clean.
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