low oil pressure rebuilt 318

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Kody meile

Kody meile

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hello everyone, i rebuilt a 318 la back in may , all new bearings and rings, cam, etc, it never gets past 25psi at 4k-5krpms, less than 10 at idle , its got a brand new oil pick up, ive changed the pump 3 times, the 3rd one i put a mopar performance spring in it, i run valvoline vr1 20-50

its always read 50psi with a drill when priming and im assuming 700 rpms with restistance when pump gets oil, ive tried 2 different guages, ive tried both guages on my 75 d100 ( also a 318 la) and both read 50 psi

any advice will be appreciated thank you
 
Was the block hot tanked and bottle brushed before rebuild? We’re the bearing all lined up correct? Have you tried a lighter oil say 10-30?
 
The lunar outlaw/utg/ nick garage 318 had low oil pressure due to pushrods length, too short.
 
Scody21 said:
Was the block hot tanked and bottle brushed before rebuild? We’re the bearing all lined up correct? Have you tried a lighter oil say 10-30?
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block was hot tanked and cleaned, cam bearings wear aligned properly and no i havent tried anything lighter
 
Did the block go to the machine shop? If it did, they remove all of the block plugs for cleaning. It's your job, not theirs to put them back, as that's part of assembly. If the plug on the driver's side oil galley in the rear was not put back, that's your problem. You can tell by removing the distributor and looking in at the back of the oil galley.
 
After the pump and gauge have been ruled out......... it’s pretty much a situation where there are more/bigger leaks downstream of the pump than what it can keep up with.

Were the bearing clearances checked before assembly?
 
RustyRatRod said:
Did the block go to the machine shop? If it did, they remove all of the block plugs for cleaning. It's your job, not theirs to put them back, as that's part of assembly. If the plug on the driver's side oil galley in the rear was not put back, that's your problem. You can tell by removing the distributor and looking in at the back of the oil galley.
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i put all the block plugs in when assembling it
 
PRH said:
After the pump and gauge have been ruled out......... it’s pretty much a situation where there are more/bigger leaks downstream of the pump than what it can keep up with.

Were the bearing clearances checked before assembly?
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yes
 
Kody meile said:
it never gets past 25psi at 4k-5krpms
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Kody meile said:
its always read 50psi with a drill when priming and im assuming 700 rpms
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My assumption is that when priming you are not spinning the crank (like a running engine does) so every opening and passage is not getting flow.Therefore the pressure might be higher.

I would have to agree with Rusty, check the rear plug.
 
Dana67Dart said:
My assumption is that when priming you are not spinning the crank (like a running engine does) so every opening and passage is not getting flow.Therefore the pressure might be higher.

I would have to agree with Rusty, check the rear plug.
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rear plug is in
 
I would Pull the pump apart and check the clearances and wear as well as for debris as long as all the lifters were pumping up and oiling properly.
 
HankRearden said:
I would Pull the pump apart and check the clearances and wear as well as for debris as long as all the lifters were pumping up and oiling properly.
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i just did all of that 2 days ago, new pump, i took it apart and lubed it and put a mopar perf spring it in
 
Kody meile said:
i just did all of that 2 days ago, new pump, i took it apart and lubed it and put a mopar perf spring it in
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Ok , I got some bad new pumps once is why I said check the clearances. I never trust a new pump anymore.
 
Kody meile said:
hello everyone, i rebuilt a 318 la back in may , all new bearings and rings, cam, etc, it never gets past 25psi at 4k-5krpms, less than 10 at idle , its got a brand new oil pick up, ive changed the pump 3 times, the 3rd one i put a mopar performance spring in it, i run valvoline vr1 20-50

its always read 50psi with a drill when priming and im assuming 700 rpms with restistance when pump gets oil, ive tried 2 different guages, ive tried both guages on my 75 d100 ( also a 318 la) and both read 50 psi

any advice will be appreciated thank you
Click to expand...


The first engine that I built had low oil pressure... Everyone kept telling me it was the bearings because the oil pump drive gear didn't mesh well and we started it and ran it for a few minutes with low oil pressure.... I didn't buy that short of run time could wipe out new bearings that fast and I was right...


I went to Ken Neve the founder of Mopar Muscle club in Chicago and he gave me the best advice to solve the problem:

Put the engine on the stand and prime the pump... Tear it down a little at a time until you see oil gushing - that will be where the problem is...

Remove the intake, timing chain cover, and oil pan and look for oil gushing out....

That's how I fixed the problem with my engine...
 
Make sure the plug is in the oil filter mount in the block, lifter galleys in back, cam plugs, plug way up under the oil pump etc
 
Leaking like a sieve internally, most likely bearing clearance.
 
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