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Engine does not run right after valve job


freedom_in_4low

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The zddp is old wisdom that doesn't apply anymore. What you're after is anti wear film strength and there are plenty of modern oils that get that property without the pounds of zinc they used to need to get it.

 
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rraulston

rraulston

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I agree that lifters on an old cam is not the way to do it. But a lot of people have done it and gotten more than 20 miles worth of driving. I needed a year which was 3k miles for me. Didn't happen. I rolled the dice and got 20 miles..... This failure, however, is a little interesting. Of course the cam is wiped out. With 150 compression on all cylinders, I wonder if i just get a reman, or do a full proper cam job. I just spent $400 on a fully rebuild head....
lifter.jpg
 

Dlo250

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Dude that sucks. If the lifter is that worn, the cam may still be good. I’d get new lifters (they are $5/each) and load then back in. Obviously change the oil filter. Then get some zddp and rotella t and try it again.
 
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rraulston

rraulston

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Dude that sucks. If the lifter is that worn, the cam may still be good. I’d get new lifters (they are $5/each) and load then back in. Obviously change the oil filter. Then get some zddp and rotella t and try it again.
This is a brand new lifter. 20 miles and the entire bottom sheared off.... Never seen that before.
 

Ephry73

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This happens when lifters and cams mismatched. During the break-in period both cams and lifters are hardened together. This allows for better cam and lifter life. When you mismatch new lifters and a hardened cam, or vice versa, you end up with metals that will chew on each other. May need to do a full engine flush just to be safe and clean the oil pan and pump pickup.

Cam and lifter set matched and break in properly will get you back hopefully
 
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Squatch

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I agree that lifters on an old cam is not the way to do it. But a lot of people have done it and gotten more than 20 miles worth of driving. I needed a year which was 3k miles for me. Didn't happen. I rolled the dice and got 20 miles..... This failure, however, is a little interesting. Of course the cam is wiped out. With 150 compression on all cylinders, I wonder if i just get a reman, or do a full proper cam job. I just spent $400 on a fully rebuild head....
View attachment 180822
Wow! That's harsh. I have used new lifters with an old cam (most recently on a Ford 200 cid straight six) without issue. Put another 20,000+ miles on it before selling it to a guy who drove it another two years without issue. Obviously, your results were quite different. Seeing that pic of your lifter might make me reconsider my past decisions. :unsure:
 

TjSteve0305

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Well, i can spin all the push rods with the exception of the cylinders with visually open/actuated valves......So I cant get a good measurement. Also think the valves are actuating about .370. I put the gauge on the rocker/valve end and rotated the engine. Its difficult at best as I couldn't find a solid piece of steel for the magnetic base, but am close. I am 1 inch away from re-installing the old lifters. Problem is Since I replaced them, I just threw them in a box and didn't mark them... I know the "rule", but at driving 3k a year, it should get me by until I rebuild it. The foot of the lifters are perfect looking.....
While mismatching old/new flat tappet cam and lifters is not a good idea and can cause serious problems, I don’t think that is your problem here.

If you can easily spin the pushrods I suspect incorrect lifters.

Might be worth checking. Couldn’t hurt.

View attachment 180798
Hard to say for sure without putting hands on it but I think this picture nails it.
 

Lou

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While mismatching old/new flat tappet cam and lifters is not a good idea and can cause serious problems, I don’t think that is your problem here.

If you can easily spin the pushrods I suspect incorrect lifters.



Hard to say for sure without putting hands on it but I think this picture nails it.

see post #22
 
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rraulston

rraulston

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Wow! That's harsh. I have used new lifters with an old cam (most recently on a Ford 200 cid straight six) without issue. Put another 20,000+ miles on it before selling it to a guy who drove it another two years without issue. Obviously, your results were quite different. Seeing that pic of your lifter might make me reconsider my past decisions. :unsure:
Most people who put new lifters on old cams get those results. My issue isn't a wear issue, its a component critical failure...
 
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Flivver250

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As far as wondering about a reman or cam job, I doubt you can trust luck after seeing this. I'd be watching for falling pianos and meteors as well. Humor aside, I think I'd go with cam, lifters and timing gears/chain at this point. If you weren't already this deep, I'd suggest a quality remanufactured engine with a warranty. You could do that anyway and keep the head in inventory for a future build on your second TJ.
 

Goatman

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But here's the thing....
I know a lot of guys that have "rebuilt" an old engine by just grabbing a bunch of lifters out of the 'small block Chevy' bucket, soak 'em for a couple minutes and slap it all together. Used pistons, rings too. Seriously 🤯. And while it may smoke a bit, have them run for years of HARD use. If I even tried that on an old Briggs engine it would throw a rod on the second pull. I like to use a 1/2 qt of diesel rated oil in older engines for the extra zinc. I've got some tractors from the late 40s-early 50s that are still running strong on that 'blend'. Don't know how important is is for these 'older' 2000's engines, but its habit and seems to work for me.
Anyway, I'd do a thorough engine flush, get a matching cam & lifter set, triple check my pushrod lengths, and go from there. Good luck.