What rockers are you using? The rocker shafts can go on 4 different ways, but only one way is correct.

I've been seeing some posts on other sites that claim some hyd.roller lifters are getting down into the main oil galleys so far and due to the roller dia. that galley oil is finding a way out due to machining areas on the lifter. Also questioned are the position of the galleys, as in the same lifters worked in a different block. Lifter brand in question were the ones you have in use. good luck

What main bearings are in it?

Focus on the main bearings, this is from experience with falling oil pressure . One or more may be 'scuffed' and have opened up clearance to lower oil pressure when things get warm. Material may be in oil filter but pull pan and check oil pressure regulator spring cavity.

Upper end internal leaks can definatly overtask the pumps ability to flow enough oil to maintain acceptable pressure. My motor pushrod oils. Until the pushrods were restricted it wouldn't make over 45psi with a high volume pump. Now holds 60 psi at idle (5w30). Mains are .004", rods are .003", lifter bore clearance .0025". If the lifters are uncovered or the rockers are bleeding it won't matter if you only have .001" bearing clearance.
Doug

Did you check your lifter bore clearance? I myself have one block that has a bit too much wear and bleeds off pressure for that fact alone.

I see that was mentioned above as well.

Here is a link to an article that shows the rocker setup, look about halfway down.

Six Pack build

I ripped this quote off from a website.

Speaking of oiling, the holes in the rocker shafts have to be properly aligned with the oil gallery in the head so that the rockers can be fed the lubrication they need. Stock rocker shafts make this easy with a notch that should always go to the left and point down when the shaft is installed. But an aftermarket shaft may or may not have the shaft (this one doesn’t). The easy way to get this right is to always install the shaft with the small oiling holes pointed down and angled toward the exhaust ports. Page also recommends removing one or both of the endcaps so that you can properly clean and inspect the I.D. of the shaft. You don’t want any grit left behind going into the rockers and ruining your valvetrain as soon as you crank the engine. Replacement plugs should be available from the manufacturer.

I think once you fix this issue you should be in good shape.

Shimming the relief spring will have no affect if the pressure drops with temperature (oil thinning out). Since he had 50 psi when cold, the spring will hold at least that pressure.

If messing with the rockers/shafts doesn't prove fruitful, and you cut open the filter and don't find anything alarming inside, I would then investigate the roller lifters being the issue.
Unfortunately, if you have most aftermarket heads you can't get a good view of the lifter valley without removing the intake and valley cover.

If you turn the motor over and cycle each lifter through it's full range while running the priming tool, you may find that several will have a huge flow of oil running out the bottom of the lifter bore as you get near full lift.

This is actually a pretty common situation, but most of the time there are only a few that really gush, and the ones that do only do it for a few degrees of rotation.

It's the occasional combination of a particular set of lifters, cam base circle, and the exact location of the oil holes in the block that ends up with most or all of them showing a large amount of oil flowing out from under the lifter.
When that's the situation you have, you end up with oil pressure problems like you're describing.

The "correct" solution for that is to bush the lifter bores, and only drill small feed holes as high as possible and still properly pressurize the lifter.

Obviously the engine is together now, so that's not a very desirable path at this point.

There are some hyd roller lifters that use fully shrouded .700 wheels and they would basically solve this issue....... If in fact this is the reason for your low oil pressure.

Of course, more than likely youd end up needing different length pushrods.......just because that's how it usually goes.

OK, thanks for all the tips.

First, I will make sure my rockers are set up properly and don't appear to be getting too much oil when running.

Then I'm going to pull the filter for inspection and change the oil to 10/40.

Last, I will try to check out the lifters and see if I can get them to gush at full lift while priming.

I am doubting that it's a lack of volume from the oil pump, as right now there is more oil making it to the top of the heads than I have seen in any other car I have ever owned...at least as far as I can ascertain thru the oil filler cap. I'm going to pull a valve cover see how much comes out. I think it may be a lot. Which really seems to point to something being up with the rocker system. It also makes me think that there is not (I hope!) a huge internal hemorrhage, or else how would so much oil make it to the rocker system?

Thanks everybody. I will report back my findings

Please hurry!

Finally got a chance to sort out the rocker system.
One of the rocker shafts had the little holes pointed to the intake side and not the exhaust, so I turned that around. They both had the holes pointing down.

I also saw that one of my pushrods had popped out of the adjuster and was pushing underneath the rocker. There was a wear pattern inside the little cup, so I know I didn't accidentally assemble it that way.

ANyway, I fixed all this and readjusted the preload on all the valves.
Didn't make any difference at all.

ALSO, I ran the motor with the valve covers off. Oil was going all over the place. I only ran the motor for about maybe +/-20 seconds. Lost about a quart of oil in the process.
I've adjust the valves with the motor running with stud mounted rocker systems before (which obviously takes a lot longer than 20 sec.) and never lost so much oil. This just doesn't seem right to me.
How much oil is supposed to be coming out?

One other thing: I recall that the roller lifters had the little holes that feed the pushrods, and my pushrods also have the little oil feed holes. THis, of course, is redundant since the rockers have a way of feeding point where the pushrod meets the rocker. This probably isn't helping the situation, but I wonder if it is really hurting things much?

when you were redoing things nothing jumped out at you that had excessive clearance or play? Is the oil shooting up or sideways & if sideways toward ex or intake. I would preoil with the drill to be able to modulate the psi/leak & be easier to spot where the big clearance is at. Keep us posted.

The part that is really obvious is the little hole at the top of the rockers that is meant to let oil leak out onto the valve stem and spring. A lot of oil shooting out of those holes, toward the exhaust side. It is a pulse, so I know it is not getting a continuous feed from a cam bearing groove.
But it just seems like WAY more oil than is necessary.
Every other engine I've ever seen run with the valve covers off, you get a little dribble of oil coming out to lube the valve stems (at an idle, that is.) This is just a whole bunch of oil coming out.

Alright, it sounds like the pushrods need to be internally restricted. I ain't never done (yet) myself but others have & lets find out what the procedure is. EDIT You mentioned roller lifters & I ain't up on them but they might need the oil to be restricted that is going into them & deal with it that way (not sure). Well we know where the problem is now.

If you are PR oiling, and normal shaft oiling, and the shafts and rockers have a holes aligned for rocker tip oiling, you have too much oil going up top. I believe that you could eliminate both the PR oiling and the tip oiling and you would still be okay.

Yeah this will be the fix ^ block the push rod hole .

what is the part number for the lifters?

I went on the comp site and they made no mention of PR oiling. (that doesn't mean much)


Joe

Comp makes no mention of PR oiling for their mopar hyd roller lifters, but that doesn't mean they don't have it.
They could be using the same bodies for bb, sb, and amc, and just using different link bars for each application......... In which case they would have PR oiling.

I would back off a couple of adjuster screws and with the priming tool verify if oil is coming out of the top of the pushrod.
If it is, replace the pushrods with some that have no oil holes.