Defective Oil Pump?

[4speed68rt]

Maybe the pump is sucking trash and clogging the pick up. It doesnt take much silicone, floating around the pan, to clog the pick up screen. If you put too much while you are assembling the motor, it squeezes out on the inside of the motor. You shouldn't need a special pan to maintain oil pressure. They came from the factory capable of at least 6000 rpms without any problems. The HP motors came with a windage tray from the factory. It keeps the oil from all getting suspended in the vortex of the high rpm crankshaft.
Also I think they only take 5 quarts total, including the filter.

 

[jimbosride]

I don't have any pressure issues while driving normal and it's even ok while smooth accelerations thru the 4 barrels. I will have to look into the pan issue. but first I think it's time to look at the pump to see what it is and because of:

> delay of pressure on startup ( maybe Normal?)
> the fast fluctuation while sifting when hot.

I just watched a video on what happens when the O ring is left out of the pump. (sucks air) or if the relief spring is malfunctioning.

Thank you everyone for the input ....

 

[RemCharger]

 

[jimbosride]

RemCharger​

That's the O ring that may be missing. Also I notice RTV squeeze out ? ...... going to remove the pump and have a look, Most likely put a new stock one in. Don't need high pressure or volume. I put a windage tray in my road runner and have never had an issue.... but no gauge

 

[fourgearsavoy]

RemCharger​

That's the O ring that may be missing. Also I notice RTV squeeze out ? ...... going to remove the pump and have a look, Most likely put a new stock one in. Don't need high pressure or volume. I put a windage tray in my road runner and have never had an issue.... but no gauge

View attachment 1460112

There really shouldn't be any sealer used around the oil pump anywhere. Remove the pump and carefully inspect the ports in the block as they may be full of silicone. The delay in oil pressure at start up is not normal to me. I get 40 PSI when cranking my engine before it starts then 70 when it starts cold.
Gus

 

[Daliant]

Here's my 2 cents, monday morning quarterback assessment of the situation, you've got a couple of issues that are stacking up against you.

#1: oil pressure is slow to come up upon first start when cold/ been sitting for a while usually is an oil filter drain-back issue or a weak oil pump or an oil pump that is sucking air.

#2: loss of oil pressure on heavy acceleration/deceleration which usually indicates low oil level or oil sloshing around in the pan uncovering the oil pickup.

#3: You stated that you have 70 psi of oil pressure cold and 20 psi when hot, that right there tells me right there that your engine has some loose tolerances' internally for a fresh rebuild.

My cheap easy bandaid fix for the situation is a napa 1374 oil filter, it's about a third of the size of a napa/wix 1515 so it won't take as long to fill up upon cold start up (oil pressure will build up quicker) I've seen oil filters cause oil pressure problems before.

Try running a thicker oil, like 15w40 diesel rated stuff, this helps where engine tolerances aren't where you'd like them to be.

Throw a napa 1374 filter on the thing and see what happens, it will cost you about 6 bucks, I'll bet the oil pressure will come up quicker on a cold start.

 

[jimbosride]

Pulled the pump on the Coronet and this is what I found. Looks like the filter to engine port is about 50% if not more covered with RTV. The builder went wild with the stuff? The "O" ring is intact. When you bolt this up that port will really close up. This stuff is like rubber. The pump is clean inside.

Would this cause Oil pressure delay on cold startup? Also starvation under hard acceleration? and fast fluctuation when shifting.... I think so? Also look the relief springs, the top came out of the engine the bottom is off the new pump. I'm going to ask the builder what kind of pump he put in because it's not on the paperwork.

 

[rickseeman]

WOW Ma Mopar says no sealant on the pump to block gasket. I guess this is why. And I don't see the o-ring that goes into the block on the oil pump. Is it there? Just WOW.

 

[jimbosride]

Yes the O ring was there ...... Replaced the entire pump with a new stock unit. Used very little sealant. Ran fine with good oil pressure all summer long with normal pressure on cold start up.

Cut filter up and it was clean.