Lifter bushing issues

[jcisworthy]

I have an AMC 401 with hydraulic flat tappet lifters and bronze lifter bushings. Some lifters are not feeding oil through the lifter.

There is a .040 hole in the lifter bushings and a ton of oil comes out of the holes with a priming tool.

The holes are so close to the same height in the bushings I will call them the same height.

Lifter to bushing clearance is around .002

I cut a groove in an extra new lifter with the same oil band width and height from the same manufacturer.

The only way I get oil to through that lifter in the hole with the issue is to clock it at the lifter bushing oil hole. If I rotate that lifter it will not flow oil again.

The bushing next to it that does oil to the rocker flows no matter where it is clocked.

Any ideas?

[1972ho]

I had to take the lifter apart and replace a spring when I had similar problem and that fixed my oil flow through the lifter.

[jcisworthy]

I would say it is a bushing issue somehow.

I swap a lifter out that did not flow oil in a hole where a lifter was flowing oil through the lifter and all is well.

Then back in the hole it was in and no oil through it again.

Everything is so close bushing to bushing it has me puzzled.

[ProPower engines]

You say the feed hole from the oil gallery is .040??
If thats the case is the hole straight through all the bushings??

[jcisworthy]

The factory gallery intersects the lifter bore it is not centered in it.

The single .040 hole in the bushing is centered in the factory gallery bore.

[jcisworthy]

The oil band on the lifters I have is narrow, maybe .200 wide. The more I think about it I may need to get a set with a wider band.

[Geoff2]

It sounds like the small 0.040" hole in the bush is missing/not lining up with the oil band in the lifter. No need to but new lifters. Determine if the oil band needs to be raised or lowered to line up with the hole.
Using a Dremel or similar, grind the groove higher or lower; does not need to be very deep. Wrap the lifter in masking tape to keep out metal.

[jcisworthy]

I am going to pull the head back off and re measure the lifter to bore clearance. I think I may have missed the set up on my bore gauge and some are tighter than I think, preventing the oil from circulating around the lifter.

I hve another block here with bushigs from the same shop and I re measured the bushings and they are tight. I am getting .0008-.0001 on some of them with that much taper.

[jcisworthy]

So I was wrong.

The lifters that do move oil through them, even though the oil band does not seem to intersect the feed hole, must be getting close enough to the feed hole to get oil in the band.

I installed a lifter with a .100" wider band on the bottom in a hole with an issue and it moves oil through the lifter now.

I will get different lifters with wider oil bands and it should do it.

[MadBill]

Or with a tiny ball cutter in a Dremel, you could slot the the feed holes to better match the existing lifters...

[jcisworthy]

Thank you for the suggestion

I would rather not take the engine back apart so if I can find lifters with a wider band, I will go with them and have the holes located higher on the next engine.

[stealth]

I have an AMC 401 with hydraulic flat tappet lifters and bronze lifter bushings. Some lifters are not feeding oil through the lifter.

There is a .040 hole in the lifter bushings and a ton of oil comes out of the holes with a priming tool.

The holes are so close to the same height in the bushings I will call them the same height.

Lifter to bushing clearance is around .002

I cut a groove in an extra new lifter with the same oil band width and height from the same manufacturer.

The only way I get oil to through that lifter in the hole with the issue is to clock it at the lifter bushing oil hole. If I rotate that lifter it will not flow oil again.

The bushing next to it that does oil to the rocker flows no matter where it is clocked.

Any ideas?

Are you turning the engine over while priming? Those flowing oil may just happen to be at a certain height on the cam allowing oil flow.

[jcisworthy]

What was confusing me is it looked like the lifters flowing oil did not intersect the oil feed hole. I could not figure it out some were flowing and others were not.

I eventually took a head off and I was able to get a better measurement which is when I found that the lifters flowing oil were hitting about .005 of the feed hole.

I ended up grooving the bushings from the feed hole up about .500 and that fixed it

[cjperformance]

Why do people have lifter , p-rod , rocker oil feed at priming problems? Not one single time have i ever had this problem. With any engine combo!

[jcisworthy]

This is the first time I had lifter bushings installed in one of these engines.

The factory oil galley intersects the side of the lifter bores, the bores are not centered. There is only one small .040 hole in each bushing and they do not feed through to the next bushing.

Having no experience with bushings in these engines, I had the bushing feed hole placed where it would be centered in the factory galley bore.

It should have been higher or if I had lifters with a wider oil band, it would have worked also. The oil band on the lifters used is .200" wide.

Like I said earlier, the thing that was really confusing me is that some were feeding oil while it sure looked like none were intersecting the feed holes.

After taking a head off and measuring, I saw that some were indeed were barely intersecting the feed holes.