410 Stoker help!!!! LOW OIL PRESSURE!!

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nm9stheham said:
Yes, it SHOULD have tons of pressure....(And yes, I have indeed pumped a pan dry in racing, and blown a filter gasket off the seat, with a too high a pressure relief valve setting.)

At the lower RPM's the oil flow from the pump drops and drops, and, in the OP's case, the pump flow is dropping a level where the back pressure with that specific pump's flow capacity at that RPM and into that particular engine is dropping sharply. If the OP has a 'loose' engine for clearances, then how the pump and system interact at low RPM's will depend on the specific pump flow.

My thought is that he just may have a particular pump with some clearances that are not tight, and/or a poor pickup situation, either of which is compromising low RPM flow. A loose clearanced or worn pump will seriously drop some % of its flow; I used to change pump covers and aluminum pump housings on a particular engine regularly, and bingo, the tight clearances would really boost flow and pressures particularly at low RPM's.

I believe you meant to say 'at the rockers'; the lifters get pressure around them all the time.
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The motor has less than 3hrs run time so the oil pump isn't worn out. I'm hoping the machine shop didn't mess up the clearances. The problem is this engine sat never ran for 10yrs so the machine shop isn't helping me. I primed the oil pump with a drill before starting it. Then ran it to breakin the cam after the cam breakin period I let it idle and noticed the oil pressure problem. I did talk to the shop that built it I was told the eagle kits they use have never had clearance issues.
 
Mooch42 said:
I checked the oil it isn't over full. How did you figure out it was deluted so bad
Click to expand...

It was a long process. When I was at the track I noticed the car was cutting out at the big end. Narrowed it down to an issue with the fuel pump. Pulled my fuel pump off and the crank trigger smelled like gas. Changed the oil and I could smell gas. I threw a reliable oil pressure gauge on it and I had like 5 lbs of oil pressure.

This was not on a big money striker engine but the motor had about 500 miles on it so I was beyond bummed. Build it bigger and build it better.
 
Mooch42 said:
The motor has less than 3hrs run time so the oil pump isn't worn out. I'm hoping the machine shop didn't mess up the clearances. The problem is this engine sat never ran for 10yrs so the machine shop isn't helping me. I primed the oil pump with a drill before starting it. Then ran it to breakin the cam after the cam breakin period I let it idle and noticed the oil pressure problem. I did talk to the shop that built it I was told the eagle kits they use have never had clearance issues.
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when you ran the drill did you turn the motor and confirm you had to oiling to both heads?
 
Mooch42 said:
I checked the oil it isn't over full. How did you figure out it was deluted so bad
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To check to see if your oil has fuel in it you can put a couple drops on the back of your hand and hold your hand down if the oil starts to crawl up your skin you have fuel in the oil I know if sounds dumb but it works.
 
Mooch42 said:
The motor has less than 3hrs run time so the oil pump isn't worn out. I'm hoping the machine shop didn't mess up the clearances. The problem is this engine sat never ran for 10yrs so the machine shop isn't helping me. I primed the oil pump with a drill before starting it. Then ran it to breakin the cam after the cam breakin period I let it idle and noticed the oil pressure problem. I did talk to the shop that built it I was told the eagle kits they use have never had clearance issues.
Click to expand...
I'm not suggesting that the pump is worn, but there are a variations out of the box in pumps; a small defect in the cover surface or in the relief valve bore can leak quite a bit. The shop would not normally have pulled the pump apart to inspect so they would not know or would not have done anything to the clearance from the factory.

It's gotta be either the load side (after the pump), or the supply side (pump and pickup). Don't dismiss anything just because of circumstantial or anecdotal info; guys can chase their tails forever on these problems because they rule out this or that upfront with no actual data. The shop's statement of 'never have clearance issues' is a great example.. what do they mean by that exactly? Do they think .003" is OK? We don't know. Did a rookie assemble it 10 years ago and miss something? We don't know.

Just work through all the easy spots to check 1 at a time and keep an open mind. Everybody's pulling for you.

BTW 8-10 psi at hot idle was not uncommon on these engines from the factory.... though I would admit that with 20W50, that IS indeed lower than expected.
 
nm9stheham said:
I'm not suggesting that the pump is worn, but there are a variations out of the box in pumps; a small defect in the cover surface or in the relief valve bore can leak quite a bit. The shop would not normally have pulled the pump apart to inspect so they would not know or would not have done anything to the clearance from the factory.

It's gotta be either the load side (after the pump), or the supply side (pump and pickup). Don't dismiss anything just because of circumstantial or anecdotal info; guys can chase their tails forever on these problems because they rule out this or that upfront with no actual data. The shop's statement of 'never have clearance issues' is a great example.. what do they mean by that exactly? Do they think .003" is OK? We don't know. Did a rookie assemble it 10 years ago and miss something? We don't know.

Just work through all the easy spots to check 1 at a time and keep an open mind. Everybody's pulling for you.

BTW 8-10 psi at hot idle was not uncommon on these engines from the factory.... though I would admit that with 20W50, that IS indeed lower than expected.
Click to expand...
I broke the cam in using 10/30 I switched to 20/50 to see if it helped but the oil pressure stayed the same. Intake and the timing cover comes off next I'm gonna make sure the galley plugs are behind the thrust plate. If that checks out I'm guessing I will change out the oil pump
 
nm9stheham said:
BTW 8-10 psi at hot idle was not uncommon on these engines from the factory.... though I would admit that with 20W50, that IS indeed lower than expected.
Click to expand...

/\ /\ My Dad use to say a good rule of thumb was 10lbs pressure for every 1000 rpm. Back then he/we would run 10w-30/10w-40.

Pat
 
Divenut said:
/\ /\ My Dad use to say a good rule of thumb was 10lbs pressure for every 1000 rpm. Back then he/we would run 10w-30/10w-40.

Pat
Click to expand...
Maybe on a engine that has some time on it but not a fresh motor with all brand new internals that hasn't even gone through the break in period.
 
PRH said:
When you’re priming it, make sure the oil appears air bubble free.

I put a SB together once where the oil had tiny air bubbles in it while priming.
The cap retaining the spring in the oil pump had a leak and was introducing air into the pump.
I caught it before running the motor, but I have to believe that would have impacted the hot pressure.
Click to expand...
Add it to my list of things to check..lol
 
it seems to me that if he is getting good pressure cold then it isnt a large leak like a plug missing or lifters leaking. It is small enough to hold pressure until the oil thins out.
How long did you prime it and did you turn the engine over while priming ? Sitting for 10 yrs would allow the bearing to dry out.
IMO...
 
mbaird said:
it seems to me that if he is getting good pressure cold then it isnt a large leak like a plug missing or lifters leaking. It is small enough to hold pressure until the oil thins out.…..
Click to expand...

Reminds me of when my Ramcharger 360 oil pump relief stuck. When I cracked the first bolt loose to take the pump off the relief popped back. That sound made me feel a whole lot better changing that pump.
 
mbaird said:
it seems to me that if he is getting good pressure cold then it isnt a large leak like a plug missing or lifters leaking. It is small enough to hold pressure until the oil thins out.
How long did you prime it and did you turn the engine over while priming ? Sitting for 10 yrs would allow the bearing to dry out.
IMO...
Click to expand...
I only ran it long enough to bring the pressure up to 50psi. I didn't turn the engine over while priming. I'm thinking if it's a galley plug it would be one behind the cam thrust plate
 
Daves69 said:
Reminds me of when my Ramcharger 360 oil pump relief stuck. When I cracked the first bolt loose to take the pump off the relief popped back. That sound made me feel a whole lot better changing that pump.
Click to expand...
My anxiety is through the roof..lol
 
Here’s what’s high on my probability list:
-too much bearing clearance
-something in the pump is out of spec
-screen is partially blocked
-oil pump mounting gasket failed or missing
-oil pump not sitting flush against main cap(seen it before).
-block originally had oversized lifters

The last one is easy to spot.
When priming, lots of oil will be flowing out around the lifters.

I’ve never left the plugs out at the front of the block so I don’t “know” how much leakage you’d get between the cam plate and block....... unless there’s a gap or something, I can’t imagine it would be much.
Could probably see it with a bore scope in through the fuel pump hole and priming it.
 
Last edited:
PRH said:
Here’s what’s high on my probability list:
-too much bearing clearance
-something in the pump is out of spec
-screen is partially blocked
-oil pump mounting gasket failed or missing
-oil pump not sitting flush against main cap(seen it before).
Click to expand...
So would you drop the pan first or check to see if the galley plugs are in place under the cam thrust plate? I'm being told if those are not there oil pressure will be low when it warms up
 
Pan or timing cover first........ hhhmmmm.......Which ever is easier in your car.

But neither till after priming while having a good view of what’s going on in the valley.
 

I don’t know if this was asked/ discussed yet......

What’s the rocker/pushrod/top end oiling situation?
 
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