lifter collapsing problem

[Turbo 6 Justin]

okay the saga continues, anyone that has followed my buddy and I getting his motor back together knows my problems (wiped cam 2 month back order finally back up and running at the end of the july) anyway everything was fine for the first 1000 or so miles, runs real strong (after babying it for 500 of course) oil looks great etc. now a new problem comes up after getting on it (16-17 psi rich 02's and EGT's fine no knock( it starts to knock real loud. first thought was cam sensor wave washer but it looked and checked out fine. started getting into the motor a little more and found #3 exhaust lifter compressed very easily. tore it and a few others apart and they all look exactly the same, no metal or aything in the bad one. So what causes a lifter to go bad after 1100 miles. everything else looks great from the cam through the pushrod rocker valve valve spring all are prefect. The lifter was also definitly spinning like it should as evidenced by the slight wear pattern on the outside of it. I assume we just need to get 1 new lifter and do another motor break-in or is it necessary to get a full new set?


so after my novel above questions are
what causes a lifter to collapse and what do you do after it happens? and why would it collapse just after it sees it's highest oil pressure, to me it makes sense that it would be louder at idle than at 70 psi. (for the record oil pressure is 75+ at start-up, 18 or so at hot idle and 65-70 at full tilt boggie)

 

[Turbo 6 Justin]

okay I'll BTT this

what causes a lifter to just go bad? everything seamed very similar between the bad one and the others, spring plunger top and everything were the same. I would be a little more worried if it was the rear most lifter on either of the lifter galley's as I would suspect oil flow problems but since it was right in the middle of the row I kind of figure that is not the problem. Any ideas?

 

[Intercooler]

What did your preload measure out at?

 

[Turbo 6 Justin]

When we built the motor after it was assembled we checked preload and though I still have lots of problems doing this correctly we did it like three different ways with 3 different measuring tools and got very close to the same reading every way. I have it written down but it was right around 35 so it should be well within spec, anly change that would effect it was the heads were shaved .006 to take out a slight porting knick so everything should be fine.

 

[Richard Inglett]

Hate to say it.

Afraid the #3 exhaust lifter is at a disadvantage. It has the least amount of offset in relation to the cam lobe.

I know you don't want to hear this but it is extremely likely that in addition your lifter, your the #3 exhaust cam lobe is also wearing and new lifter will not help.

Some of the reasons cams go bad include improper pre-load, mis-aligned lifter bores, wrong springs or my favorite the porosity filled cam. You may even hear that your oil is to blame. Advise selecting a cam that others have had success using, verifying the basics and following the breakin instructions. For cam recommendations, a billet roller or a flat tappet with 30,000 miles or more should be a safe bet.

If you do have to replace the cam, strongly recommend dropping the oil pan to check for metal. If there is any metal, check the bearings (especially the #1 rod bearing) and replace your oil cooler. After cam breakin, drain and replace oil then drain and replace again after about ten minutes of idling time.

Good luck

 

[Turbo 6 Justin]

I had thought that at first and I know that is the lobe that likes to get dropped and actually in his block the alignment looks a lot better than a lot of locks I have seen and the lifter definitly shows signs of properly spinning in the bore. It is a strange feeling with the valve cover off if you push on the pushrod you can depress it by hand while the others have a lot off resistence. after taking another one out and taking it apart so it has no oil in it it feels exactly the same as the 'bad' one. also it is an intermittent problem so I really doubt it is the cam itself, been there and done that already so I am familiar with the symptoms. keep them coming

and please don't ask what I am doing up at 3:30 in the morning the sad this is I already got my 2 hours of sleep already and this is good morning for me.