Any Pontiac guys on here? Need insight.

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I ran oil pump with drill on two diff engines with hydraulic lifters, one mopar, one small block Ford. In both cases oil visibly flowed to all 16 rocker arms without turning crank. And it was real obvious oil was flowing with valve covers off. I could see oil flowing out of push rods filling up heads and dripping down sides of engine.

Other thing I did was hook oil pressure gauge up to block while running drill.

Now if there is some other type of lifter that only oils when engine is running that I haven't seen.
 
So, tonight I took apart a small block Mopar lifter (AMC) style lifter tonight for investigation purposes. What I found was the disk in these lifters has and pattern stamped in them to allow oil out of the inner chamber and out the top of the lifter. This helps confirm that the lifters in the 400 Pontiac are causing my problem.

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Plym 67,

Don't you think it is strange that all 16 lifters could be faulty???? I don't think they are. I described earlier in this thread that the engine might need to be running to pump oil up top. I suspect all the lifters pumped up when you primed the engine. See the pic below, it is an original lifter out of a 1971 Pontiac 455 block.
The black dot on the flat disk is carbon build up, not a hole. The underside of the PR socket is slightly rounded, as per the drawing. On the disk, you can clearly see the shiny area around the carbon dot. It was sealing off the hole in the prod socket. Oil pressure enters the chamber & pressurises in all directions, pushing the disc up against the PR seat; blocking the hole, no oil flow....No oil flow until a gap appears between the disc & the socket...which will happen as the lifter bleeds down slightly passing over the cam lobe.
The lifter design that uses the 4 hole disc. I have some of these. Work on exactly the same principle [ bleed down ]. The underside of the PR seat is flat. The none of the 4 holes in the disc line up with the hole in the PR skt. Oil pressure enters the chamber, & forces the disc against the PR skt. No oil flow into PR seat. The purpose of the 4 holes is so that once a gap appears, the oil pressure can enter via the 4 holes & allows oil to get to the hole in the PR seat.
Solid lifters that oil through the PR: shake them, they rattle. The rattle is the clearance of the met disc & PR seat moving around. A small gap for oil flow. These would pump oil up to the top without the engine running.

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Bewy said:
Plym 67,

Don't you think it is strange that all 16 lifters could be faulty???? I don't think they are. I described earlier in this thread that the engine might need to be running to pump oil up top. I suspect all the lifters pumped up when you primed the engine. See the pic below, it is an original lifter out of a 1971 Pontiac 455 block.
The black dot on the flat disk is carbon build up, not a hole. The underside of the PR socket is slightly rounded, as per the drawing. On the disk, you can clearly see the shiny area around the carbon dot. It was sealing off the hole in the prod socket. Oil pressure enters the chamber & pressurises in all directions, pushing the disc up against the PR seat; blocking the hole, no oil flow....No oil flow until a gap appears between the disc & the socket...which will happen as the lifter bleeds down slightly passing over the cam lobe.
The lifter design that uses the 4 hole disc. I have some of these. Work on exactly the same principle [ bleed down ]. The underside of the PR seat is flat. The none of the 4 holes in the disc line up with the hole in the PR skt. Oil pressure enters the chamber, & forces the disc against the PR skt. No oil flow into PR seat. The purpose of the 4 holes is so that once a gap appears, the oil pressure can enter via the 4 holes & allows oil to get to the hole in the PR seat.
Solid lifters that oil through the PR: shake them, they rattle. The rattle is the clearance of the met disc & PR seat moving around. A small gap for oil flow. These would pump oil up to the top without the engine running.

View attachment 1716211024
Click to expand...
I have ran the engine with the valve covers off and there was no oil getting up the push rods. Do I think all 16 are faulty? No but, do I think they could be damaged from in proper valve adjustment? Maybe. I realize that these restrictor disks were never shaped like the one I took apart from small block Mopar. It has oil pressure, it floods the lifter with oil but, no oil comes out of the lifter. Pushrods are clear, oil is flowing...nothing to the top end. I have a lifter coming from a running 400 of a guy I know who is doing a cam swap on his engine. I'm going to do some testing with it to see what I think.
 
Bewy said:
Well if you have run the engine, & no oil, then there is a problem....
Click to expand...
Right best to address the obvious, get that fixed, see what happens from there. Sure some other problem(s) may still exist. But if oil aint flowing up, soaking head, running down side of block, splashing oil everywhere causing a giant mess with ppl screaming shut the engine off, then yeah its messed up corrective action required.
 
Well, today was the day. I got a known good lifter from a guy I know and tested my theory. First I popped the pushrod seat out of it and, low and behold it has the pattern stamp into the restricer disk. Put it back together, put it back in the car and, it oils the valve train. No other lifter even spurted out any oil. Moved it to another hole and...it oiled that rocker arm. New lifters have been ordered.

20240222_143232.jpg
 
hmm... how long does assembly lube stay on parts... :p

hopefully nothing is totally scorched!
 
I showed this on another thread... something I'm working on with a customer...
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Pontiac love...
It's a 440...
 
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I realize that you are moving forward by replacing the lifters. Posting this for reference.

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butlerperformance.com

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So, the new lifters are here. I popped one apart and low and behold they look about like I anticipated. I'm super ready to put these in and start putting it back together.

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Is the disc flat? Also, is the underside of the prod socket also flat?
 
Yup,
I know the disc is flat. I have used those same lifters. But is the underside of the prod socket also flat, cannot remember?
 
To be honest I didn't pay attention. I saw the holes and was pleased with that.
 
Waiting to see if oil gets pushed up through all 16 rockers when you run oil pump with drill.
 
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