Lets play a game: Lifter vs Cam

[NightTrain66]

is there scratches or svoring on the sides of the bad lifters?

If so, is it any worse that the other 14?

I doubt that is the problem to be honest.

I believe the LS7 liftres were collapsing a lil (you mentioned noisy lifters) and as thy collapsed either varying the load from lifters to cam or possible causing valve float or valve trane "trauma".

You night have had this problem on more than 1 cylinder, it is just that these 2 were the first 2 to give upa nd if these did not have a problem, it was only a matter of time until "some" had the problem.

Lunati makes a $220 set of 72430-16 lifter that is MUCH better on the inside and can handle more pressure and abuse than the std 72910-16 lifter but still be a lot more forgiving on lifter preload than the Comp 875-16 (R lifters).

Lloyd

[shownomercy]

is there scratches or svoring on the sides of the bad lifters?

If so, is it any worse that the other 14?

I doubt that is the problem to be honest.

I believe the LS7 liftres were collapsing a lil (you mentioned noisy lifters) and as thy collapsed either varying the load from lifters to cam or possible causing valve float or valve trane "trauma".

You night have had this problem on more than 1 cylinder, it is just that these 2 were the first 2 to give upa nd if these did not have a problem, it was only a matter of time until "some" had the problem.

Lunati makes a $220 set of 72430-16 lifter that is MUCH better on the inside and can handle more pressure and abuse than the std 72910-16 lifter but still be a lot more forgiving on lifter preload than the Comp 875-16 (R lifters).

Lloyd

Negative on any lifter OD looking worse or different than others. So, this last set of measurements was just to confirm that the block was consistent across the board and nothing is out of wack. [downside to having a lot of waiting time, and being a perpetual worrier]

So I am now more confident that the LS7 lifters in cylinder 1 indeed were crappy from OEM and perhaps collapsed enough to bounce on the cam lobe, which would correspond with the noisy valve train that would not change based on valve adjustment.

I purchased a crower link bar set, 66310LM and while on the phone with the lunati valve train tech I just sourced a new billet cam via him. Last variable will be the pushrods and I will make sure they are the largest OD I can get That and triple check the valve springs again for installed height.

Think I covered the bases.

[NightTrain66]

That should fix it up.

Just get plenty of seat pressure for what ever they lobes they used and the boost on top of that.

Did you get a cast gear on back of the billet cam?

How much do they sell billet cams for?

Lloyd

[shownomercy]

That should fix it up.

Just get plenty of seat pressure for what ever they lobes they used and the boost on top of that.

Did you get a cast gear on back of the billet cam?

How much do they sell billet cams for?

Lloyd

Its only 3* more than the original cam, 227/227 114 +3 I think. $350 for a billet "custom" cam from them, and yes, got it with the cast/everwear gear even though they argued and said I didn't need it.