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

[mderoy340]

I would pull both valve covers and prime. If you see small air bubbles after priming for awhile I would suspect the pump. No air bubbles I'd check the lifter galley plugs first.

 

[PRH]

Crane golds.

Pushrods with or without holes?
Hyd or solid cam?
Lifters that pushrod oil or not?

Lifters and pushrods with holes and a solid lifter cam will create 16 extra leaks when the lobes are on the base circle.

Normally this doesn’t cause much drop in pressure....... but they are extra leaks that aren’t part of the “normal” oiling circuit.

This is especially true with some of the Schubeck and Tool steel race lifters where the thru holes aren’t metered.

 

[Mooch42]

Crane golds.

Pushrods with or without holes?
Hyd or solid cam?
Lifters that pushrod oil or not?

Lifters and pushrods with holes and a solid lifter cam will create 16 extra leaks when the lobes are on the base circle.

Normally this doesn’t cause much drop in pressure....... but they are extra leaks that aren’t part of the “normal” oiling circuit.

It is a hydrologic flat tappet cam and lifters

 

[PRH]

It is a hydrologic flat tappet cam and lifters

Holes in the pushrods or not?

If there are, look to see if there’s any leakage around the adjuster/cup while priming.

 

[nm9stheham]

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

I'd do the least invasive 1st:
- do the pumping tests and views
- then pull the timing cover and check for the plugs

If you catch a problem either spot, that may be as far as you need to go. Also, I'd dig and pester to find out the bearings types it humanly possible: if full flow main and full flow cam bearings were installed, then those are sources of more oil flow and lower pressures.

Looking down the road, if all else fails to give a quick solution, then the oil pump attention is next IMHO. At that point, it might be just as easy to pull the whole thing. But if you could pull just the pump, it might shortcut the issues if you find clearance are on the loose side, or if there is an issue around the relief valve. I would try to find a 'tight' pump if the one you have is loose on clearances. Otherwise, it is down to ripping it all apart.

Unless you can live with the pressures. At idle, it is not like the system is not getting oil or being loaded hard the fact that you have pressure at all says that there IS flow into the system. And, If' twer me, after enough miles are on the engine, I'd absolutely put in synthetic and keep going. Synthetics maintain a more stable viscosity when hot, which will keep your oil pressure up, and the overall protection is light years ahead of standard petroleum oils. I've had race engines survive extended oil pressure losses on synthetic.... Honest story here: I ran zero oil pressure for 2+ minutes at 75% effort in a turbo rally car (Yes, I backed off 'a bit' when the oil pressure gauge hit zero! LOL) Refilled the oil after the stage, fixed the leak, and finished the event (another 100 full race miles plus more transit miles), and it showed perfect bearings at tear down after the event. (I have a witness to that fact.) And I did it again the next year in the same rally car! So the protection is far, far, far better than an old fashioned oil like Kendall.

 

[Cal Tonsley]

oil pump sitting flush is a good point ! You arent by chance running main studs are you?

This is a really good point I think. With my engine I had to mill the oil pump mating surface to get it flat and even with a main cap bolt (had studs elsewhere) I had to shorten its head and clearance the pump body to allow the pump to mount flush and torque up! These could potentially be areas overlooked in the original build.