mchicia1

iTrader: (5)

My new LS7 lifters have begun ticking at 1600 rpms and under. It's an off beat tick, like the lifter is intermittently bottoming out.

I took the VCs off and measured zero lash on 4 valves and came up with:

-Intake: 7.262"
-Exhaust: 7.275"

I have 7.375" pushrods in there now, so way too long. I bet if I had 7.4s the car wouldn't even run. I must have screwed up the measurement before because the lifters were new and I must have pushed the spring down while trying to measure.

Anyway, I just ordered 7.325s, but could the damage be already done? Put my mind at ease.

If not, I'd rather swap the lifters out now while the cam and block are still ok than risk running with hurt lifters that are going to cause me more pain and money later if they let go.

Darth_V8r

iTrader: (4)

Suggestion - measure zero lash for all 16. You might find one that is something like 7.35 which would tell you you have a collapsed lifter. Or you won't in which case you're making a more educated decision on PR length

100 preload should honestly be ok for LS7 lifters

mchicia1

iTrader: (5)

Gotcha, makes sense. The preload on the intakes is .113 though, which seems like a lot. I would think since there is not much oil below the plunger, at low RPM it may have trouble keeping the lifter pumped up. Plus the intake valve is the large valve, although I did get the LS3 hollow stems at least.