Lifter wear , valve stems, etc...

[Mr Brown]

I pulled out a couple lifters today, cyl #4, to bleed them. I noticed quite a lot of wear on the cam end of both. The exhaust valve lifter had an odd wear pattern, it was concave except for the very middle where there was a little nub left about .003" to .005" high and 1/8" in diameter. The intake valve lifter was very much concave, at least .010" and you could see very slight pitting. Unfortunately I did not have a look at the cam lobes, although the backsides had a ok looking pattern to me, meaning a narrow wear pattern. From what I saw, I will need a set of lifters in the near future. My question is, should I also assume the cam to be unserviceable? and if so, is there any point to changing the lifters at this time. The engine is in good condition, PO put on new heads, pistons, rings etc... about 10,000 Kms ago.

I also noticed a couple of valve stems had pitting on them already, heads(AMC) have less than 10,000 Kms on them. The adjusters are worn but not pitted. Is this cause for concern?

Also, all the valve adjusters are screwed in almost all the way. Is this normal with AMC heads on a stock engine? AC 2.0 in an 82 Vanagon.

[Terry Kay]

You can assume all kinds of things, but from what I have seen in engine's, if you have found the lifter face wearing out you can amost bet the cam lobe is going bye-bye too.

Why did you skip taking a look at the camshaft?

You for sure wouldn't be here asking what anyone might think--you'd know already.
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T.K.

[Wildthings]

Type 4 VW engines have funny wear patterns on their lifters. Not much you can do about it.

If your engine makes sufficient power and otherwise runs okay, just put it back together again and run it. If the power is off or it can no longer be tuned to run well then it is time for some bottom end work.

[Terry Kay]

Prior to taking the time to bolt eveything back up--and knowing you have a cupped out lifter face, it would be a very prudent move on your part to take a look using a proctoscope or some other internal visual inspection devise to determine what state that camshaft is in.

The lifter wasn't rotating on the camshaft, and ate the face of itself up, regardless of the weird lifter wear pattern's the horizontal engine lifter's may allegidly have.

It would be a real dumb move to button it all back up "to see how it runs"--and for how long, with out verifying that the cam lobe is OK.

I hope that you didn't stuff the worn out lifter back into the engine.
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T.K.

[Wildthings]

I see nothing in his description of his lifters that would indicate to me that his lifters were not rotating. It sounds like a normal high mileage wear pattern. The little nub is present because it aligns with the deep wear in the center of the cam. With each lifter contacting only 2/3rds of a lope, T4 lifters just wear funny and I can guarentee you his cam will have a deep groove in the middle as well, they all eventually get one.

Will the engine die tomorrow if he just bolts it back together? Not likely. Will his engine run well for another 100,000 miles if he does not tear it down today? Probably not, but so long as it runs well tosay I would not mess with it.

If he wants a new perfect engine then buying a core and reworking it while he drives this one would make sense. I just can't see downing his van at this point because he has worn, but still functioning lifters.

[tencentlife]

That odd lifter face you describe, with a raised nub in the center, definitely says that that cam lobe is laterally rounded at the lobe tip. That would have to be pretty severe wear. You need to get into the bottom end without a doubt. The lifter sounds like it is rotating in its bore as it should, but the cam has worn it to match the lobe's bad tip. T4's had a bad record with cam wear anyway, so you're looking at a classic case, in my opinion.

As to the valve stem wear at such low miles on the part, it's probably also a classic case of someone buying nice new AMC heads but not replacing the valves with quality components. The AMC castings are great, but the hardware they put in is crap.

If you have to keep it running for now, I would just put those lifters back in their original places and button everything back up. Putting new lifters in with such a worn cam will only wear the new ones out prematurely and you will have wasted your money for no benefit. I wouldn't guess that any failures are imminent, but you should definitely be preparing to go thru that motor top to bottom before things get much worse. Plan on buying a new cam, full lifter set, all exhaust valves and possibly intakes, new adjusters, and whatever else turns up. Your pistons and liners are probably decent with such low miles, so honing re-ringing while it's apart would suffice and save you the expense of a new P&L set.

And make sure you learn how to do the initial run-in once it is rebuilt. The first half-hour of running is critical for work-hardening the cam and lifters, and the first road-trials are critical for seating the rings. Learn how to do it right. The conventional wisdom of babying a new rebuild practically guarantees that you will never get full compression out of the rings, and that you will not get maximum cam/lifter life.

[Mr Brown]

Thanks for all the words of wisdom. I did put the lifters back in as the van is a daily driver for short trips. The engine runs fine and I was only pulling the lifters out to bleed them. I didn't have time to do all the lifters on that side so I will be back in there to do cyl #3's lifters, at that time I will have a look at the cam. We put very few kms on the van in a year, less than 4000 anyhow, so from what has been said here I should be OK for at least this summer.

I like the idea of tearing the engine down sooner than later and reusing some of the newer components, head castings, pistons and liners, etc.. in the rebuild to save some money. My original plan was to chuck everything but the case and crank on the rebuild, but then I was assuming the bottom end was good and that I would have gotten reasonable service out of the PO's new parts before scrapping them.

Right now the engine runs great and I really need it on the road for the next six months, after that I can take it off the road if need be. I will know more after I look at the lifters and cam lobes for #3.

Thanks for all the input.