understanding a low oil pressure 360

[70 Duster Herb]

I don't post here much, but none of my research has produced much. Everyone always pointing to galley plugs or just random things to attempt to help.

360 rebuild
5w-20 lucas break in oil
solid lifter roller tipped adjustable rockers
new bearings fresh hot tank reassembled, 90-degree oil filter housing with WIX filter.

Running idle cold oil pressure at 10 psi
spun the oil pump with a drill pre-start up and post start up; I get 25 psi with no oil up top and when I position the cam and crank 2 separate positions both rocker shafts get 25psi. low speed on my drill, I increase speed pressure goes up.

it seems I have all plugs in and have verified all but two, not sure if 7.5 inches down the oil port on the China wall indicates no plug or if it's there, but through all I have read it's there. and behind the oil filter housing haven't looked yet, But I remember seeing one, but I'm old and have slept and drank since then.
spun pump with oil filter off (nice mess because it wasn't on purpose) and getting a lot of oil there.
Rockers are getting a lot of oil while I spin the pump manually, flows out of heads on to the headers So I'm getting oil throughout engine.

running out of possibilities.

Kind of thinking out loud here: If no plug under the 90-degree oil filter housing, should be no pressure at all.
if the pump where bad there would not be pressure or very little while spinning manually.
Best I can tell the oil, while engine running, is leaking off somehow and somewhere or not getting picked up.
I was mulling this over and I can't think of where the oil is going. only thing I can come up with is that the pump (suction side of the milling pump) is pulling air at a higher rpm than the drill is making, or the higher rpm is producing enough pressure to overcome the pressure side but before the pressure gauge, gasket. I did use the oil pump gasket and torqued to spec.

I have compared pump drive shafts and I get full engagement.
When I did start the engine, it sounded good nothing rattling or knocking or pinging.

Does anyone have a different theory? same? looking for ideas before I remove the oil pan and 90-degree oil filter housing oil pump engine and brainstem.
thanks y'all

 

[Professor Fate]

If you get to the point where you pull it back apart, check the relief valve on the pump. Seem to remember a couple people saying they have found machining debris holding the relief partially open.
Is the pump a stock, high volume, or high pressure model?

 

[67Dart273]

As far as I know the "big mistakes" for oil plugs are the two up front where the lifter galleys terminate, the screw in one INSIDE the block back by the dist, and then the little tiny one up in above the oil pump. I too do not remember the dimension anymore. See if I can find it.

EDIT: here Post no.4

360 Oil Galley Plugs???

I'm rebuilding a mid 70's 360 and I need to make sure I have all my plugs in place. I know that I have all the ones in place that I took out including the one in front of the distributor drive, accessed and recessed from the rear. I was online and found this article and I can't figure out...

www.forbbodiesonly.com

 

[67Dart273]

The one that is INSIDE the block back by the dist you can see by removing the dist. and looking down in. We had one member that claimed he installed a missing one through the dist. hole.

340 oil galley plugs

I'm looking for verification on an oil plug problem. My brand new 340 build destroyed the main bearings in 6 hours running. Found metal on the magnetic pan plug. Changed the oil 4 times thinking the machine shop didn't clean the block and it was flushing but the metal kept coming. I know I...

www.forabodiesonly.com

 

[TT5.9mag]

What is the mains and rods bearing clearance? Did you prime it with the intake off to look for bleed off at the lifters? What specific solid lifter are you using?

 

[Cal Tonsley]

Have you checked the gauge that you are using - Perhaps it’s reading incorrectly?

 

[70 Duster Herb]

What is the mains and rods bearing clearance? Did you prime it with the intake off to look for bleed off at the lifters? What specific solid lifter are you using?

This was a discussion I just had with a real live GURU engine builder. Mr Devine.
He told me about rod clearances on the sides. aftermarket being more clearance than stock rods. we discussed the very thin oil not getting restricted and allowing oil to pass by these clearances while the crank is turning. and while stationary the clearances are restricted due to no movement. basically, the discussion was more about pressure not necessarily about engines. understanding that good pressure is, the one you want, and too much pressure could indicate a flowing problem and too little pressure could mean many things including a bleeder around a heart or the pump not working correctly sucking air etc.

oil ports yeah got two up front, the one by the dizzy there as well and the one that is in the oil pressure gauge port is 7.5 inches down, I measured it on a suggestion from another post.
I did not plastigauge the rod clearances. yes, this was a mistake one I doubt I will make again. but We live life with our mistakes just not ever again. I did the prelube with intake off and I did not notice oil coming out of these spots because I wasn't looking or even thinking about it. next time I have an intake off I will look for it.

The result that I was told to go with: change the oil to a 10w40 break in oil (also suggested 30w as another option even said 5w30) change the oil filter. lube the engine again manually spinning pump. then start it. wait for pressure to come up. shut it down quickly if it doesn't come up.

will post results after an oil change.

 

[Ironmike]

Flat tappet lifters, correct?

 

[Mopar Tim]

The one that is INSIDE the block back by the dist you can see by removing the dist. and looking down in. We had one member that claimed he installed a missing one through the dist. hole.

http://[URL]https://www.forabodiesonly.com/mopar/threads/340-oil-galley-plugs.377270/

[/URL]

I did.....

 

[PRH]

I’d try the easiest thing first……..thicker oil.

 

[Ironmike]

Thicker oil may seem to help, but there's no way that pressure should be that low with ANY oil. Find the problem.

 

[70 Duster Herb]

gauge is good
do they make roller flat tappet? I think an older version crane solid flat tappet.
Ironmike I welcome to hear what you think but like I've said I'm not sure about any of it but theoretically what Mr Devine and I chatted about makes more sense than anything else...... sometimes the easiest solution is the solution.

 

[replicaracer43]

This was a discussion I just had with a real live GURU engine builder. Mr Devine.
He told me about rod clearances on the sides. aftermarket being more clearance than stock rods. we discussed the very thin oil not getting restricted and allowing oil to pass by these clearances while the crank is turning. and while stationary the clearances are restricted due to no movement. basically, the discussion was more about pressure not necessarily about engines. understanding that good pressure is, the one you want, and too much pressure could indicate a flowing problem and too little pressure could mean many things including a bleeder around a heart or the pump not working correctly sucking air etc.

oil ports yeah got two up front, the one by the dizzy there as well and the one that is in the oil pressure gauge port is 7.5 inches down, I measured it on a suggestion from another post.
I did not plastigauge the rod clearances. yes, this was a mistake one I doubt I will make again. but We live life with our mistakes just not ever again. I did the prelube with intake off and I did not notice oil coming out of these spots because I wasn't looking or even thinking about it. next time I have an intake off I will look for it.

The result that I was told to go with: change the oil to a 10w40 break in oil (also suggested 30w as another option even said 5w30) change the oil filter. lube the engine again manually spinning pump. then start it. wait for pressure to come up. shut it down quickly if it doesn't come up.

will post results after an oil change.

If that guy, whoever he is, thinks oil pressure is related to rod side clearance, then he should be called a "idiot" not a "guru" that IS not your problem!

 

[70 Duster Herb]

If that guy, whoever he is, thinks oil pressure is related to rod side clearance, then he should be called a "idiot" not a "guru" that IS not your problem!

well since he is 80 and a world record holder at the salt flats (the engine he built) and in the hall of fame for his contributions to the racing community (Washington state) and building mopars for 60 years. maybe you can lend your knowledge to the community. otherwise moving along is a good path.

 

[TT5.9mag]

I set two FIA world records in two days at Bonneville. Doesn’t mean ****. I agree with @replicaracer43 that rod side clearance is not what’s causing this. That would be way down a long list of guesses at this point. Pressure is resistance to flow. Period. It’s not new news. Somewhere you have a big leak and it needs to be found. The relief valve in the oil pump, the lifters, oil galley plugs, those type of things would be high on the list to check first. Since you didn’t measure bearing clearance when assembling you absolutely cannot rule that out.

 

[RustyRatRod]

well since he is 80 and a world record holder at the salt flats (the engine he built) and in the hall of fame for his contributions to the racing community (Washington state) and building mopars for 60 years. maybe you can lend your knowledge to the community. otherwise moving along is a good path.

He's being straight up with you. Rod side clearance ain't a "thing".

 

[TT5.9mag]

The reason it makes more pressure on the drill vs when running is the drill is likely running twice or more the rpm that the oil pump is normally running when driven by the cam at idle.

 

[Ironmike]

What is the mains and rods bearing clearance? Did you prime it with the intake off to look for bleed off at the lifters? What specific solid lifter are you using?

This could very well be the problem.
Get a plan. Check everything possible from easiest to most difficult.......ya know..... try a different gauge, try a different oil filter. I've seen a brand new Napa Gold(Wix) create a similar problem.
Maybe check the right angle adapter thoroughly. Personally, and I don't want to start anything, I don't like them.
Visually check for the aforementioned plugs. If all looks good, pull the intake and see what your lifters are doing while priming with a drill. You MAY just have 16 friggin oil leaks. I know from first hand experience ROLLER lifters can cause that. Maybe the wrong flat tappets can, too.

I guess if all that you can verify is ok, then it's time to pull the pan. I know that's not fun but you cannot run around with that low a pressure.
One thing. From your description it sounds like you're getting an awful lot of oil to the heads.

Sure hope you can get it sorted out. Just be brutal in your endeavor.......FIND that damn problem! You can do it with the help of this forum. I can't tell you how many times over the years this place has saved my butt.

From A to Z someone here is an expert.

 

[replicaracer43]

well since he is 80 and a world record holder at the salt flats (the engine he built) and in the hall of fame for his contributions to the racing community (Washington state) and building mopars for 60 years. maybe you can lend your knowledge to the community. otherwise moving along is a good path.

What were the actual bearing clearances when you assembled the engine?

 

[replicaracer43]

I see now where you said you didn't measure the bearing clearance. That's a big no-no and will be extremely difficult to keyboard diagnose without knowing that. One other internet "mopar guru" built a 318 recently that went for a famous online dyno test, and he assembled the engine with std bearings, and a .010 under crankshaft, and it had low oil pressure also. Could be cause

 

[Newbomb Turk]

What were the actual bearing clearances when you assembled the engine?

That’s what we need to know. What are the clearances and what lifters is he running.

As for the plugs…the plugs that go into the lifter galleries don’t do ****. I never ever use them. If the oil leaks around the plate a little so be it. As long as the cam plate is on it will make pressure whether or not those plugs are in there.

The plug under the oil pressure port will not change oil pressure if it’s left out. Not a single pound of pressure will change if that plug is in or not.

It does change the way the oil is filtered though and it needs to be in for that reason.

I’m not standing in front of a block but IIRC the plug under the right angle adapter can be out and you don’t lose pressure. You just allow dirty oil to bypass the filter. Not good but not a pressure loss.

The other plug is the one that blocks the rear of the drivers side lifter gallery. It has to be in there. You access it from the back of the block and you remove the plug at the bell housing to gain access to that plug.

You can pull the distributor and see if that plug is there. If it’s not, you can with much patience and maximum swearing get that plug in through the distributor hole. Worse case scenario is you have to pull the intake to get to it, but it can be fixed without dropping the gearbox.

Oil leakage at the rods is controlled by the diametrical oil clearance. .0035 on the rods will leak more oil that .0020 will at the exact same side clearance. That’s the FACT.

Rod side clearance should be no less than .025 but good luck getting it. The rods are too wide as it is.

Rod side clearance isn’t your issue and neither is the 20 grade oil.

 

[TT5.9mag]

That’s what we need to know. What are the clearances and what lifters is he running.

I asked in post 5 about clearances and what lifters. He didn’t check clearances and didn’t answer the lifter question.

 

[RustyRatRod]

I asked in post 5 about clearances and what lifters. He didn’t check clearances and didn’t answer the lifter question.

I don't see how the heck anyone can help him until that's found out. I know a guy who built a slant six with standard crank bearings on a .010 under crank. It actually had "decent" oil pressure until it got the least little bit of heat in it, then it didn't have "much".

 

[Newbomb Turk]

I don't see how the heck anyone can help him until that's found out. I know a guy who built a slant six with standard crank bearings on a .010 under crank. It actually had "decent" oil pressure until it got the least little bit of heat in it, then it didn't have "much".

Here’s an oldie but a goodie.

Before I could get an A in senior auto shop in school I was required to build an actual engine for someone who wasn’t me. There were 6 of us that had to do it. The bottom feeders in the class didn’t have to do it.

So I hooked up with a friends brother to do his 318. We had a whole list of **** we had to do to pass and that included all ring gaps, all bearing clearances, deck heights…all that.

I got the crank in, degreed the cam and didn’t measure the rod throws before hand so I said “this junk was all machined so it’ll be fine” and sent it.

I get 5-6 pistons in and I can hear a clunking as I’m turning it over. I’m thinking WTF is hitting what. Didn’t see ****.

So the teacher strolls over and looks at my paperwork. He says how much rod bearing clearance do you have? I say .0025 for the mains.

Like a dickhead, I lied and said .0025 just like the mains I just didn’t write it down yet.

He looks at me funny and walks over to the garbage can, pulls out the box the rod bearings came in and said “measure it again, get it right and then head to the office”.

So I took all the junk back apart, torqued the rods back up and started checking them. Instead of the .0025 I should have had, I had .0125!

Now I’m triple pissed because the guy I paid to the size the rods dicked me. I’m running around like a chicken without a head and the teacher comes over and says I didn’t take that box out of the garbage for no reason.

I’m looking at it and is says .010 under right on the box. I’m thinking WTF I’m in trouble for lying and I have no clue what’s wrong.

After about 20 minutes of nonsense from the rest of the class I decided to pull the bearings and measure them to see if they were screwed up.

Of course, I looked at the back of the bearing and it said .020 under on them. All the bearings were .020 under and every box said .010 under on them.

Hard lesson learned that day. You can’t measure enough. If it can be measured it should be measured.

My punishment for lying was I had to wash all his cars. I did 6 of them before I figured out only two were his. The other 4 belonged to other teachers.

I still got my A though.

 

[RustyRatRod]

Here’s an oldie but a goodie.

Before I could get an A in senior auto shop in school I was required to build an actual engine for someone who wasn’t me. There were 6 of us that had to do it. The bottom feeders in the class didn’t have to do it.

So I hooked up with a friends brother to do his 318. We had a whole list of **** we had to do to pass and that included all ring gaps, all bearing clearances, deck heights…all that.

I got the crank in, degreed the cam and didn’t measure the rod throws before hand so I said “this junk was all machined so it’ll be fine” and sent it.

I get 5-6 pistons in and I can hear a clunking as I’m turning it over. I’m thinking WTF is hit what. Didn’t see ****.

So the teacher strolls over and looks at my paperwork. He says how much rod bearing clearance do you have? I see .0025 for the mains.

Like a dickhead, I lied and said .0025 just like the mains I just didn’t write it down yet.

He looks at me funny and walks over to the garbage can, pulls out the box the rod bearings came in and said “measure it again, get it right and then head to the office”.

So I took all the junk back apart, torqued the rods back up and started checking them. Instead of the .0025 I should have had, I had .0125!

Now I’m triple pissed because the guy I paid the size the rods dicked me. I’m running around like a chicken without a head and the teacher comes over and says I didn’t take that box out of the garbage for no reason.

I’m looking at it and is says .010 under right on the box. I’m thinking WTF I’m in trouble for lying and I have no clue what’s wrong.

After about 20 minutes of nonsense from the rest of the class I decided to pull the bearings and measure them to see if they were screwed up.

Of course, I looked at the back of the bearing and it said .020 under on them. All the bearings were .020 under and every box said .010 under on them.

Hard lesson learned that day. You can’t measure enough. If it can be measured it should be measured.

My punishment for lying was I had to wash all his cars. I did 6 of them before I figured out only two were his. The other 4 belonged to other teachers.

I still got my A though.