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I was trying to measure push rod length on my 489 build. Measurements didn't make sense, they kept changing.
Then I noticed the dial indicator moving on its own! The checking springs are overpowering the springs in the Morel Street lifters!
I'm not sure if the solid version of the lifters are same height as the hydraulics. They are Morel Street hydraulics.
Shimming the lifters would be possible, but then I would need one extra lifter pair (I wouldn't want to re-use the lifter after having taken it apart and put stuff inside).
Today I cut the checking springs, but it seems that they are either too hard at full lift or too weak at no lift depending on how much I cut off. I guess I should get a better set with weaker (thinner material) so that the difference in tension will be less as the spring is compressed.
How do I know i have a broken valve spring? My mechanic says i may have one. The engine misfires occasionally. Yet I have no service engine soon light come on. I use to think it was the mild camshaft in the LT1 making for a rough idle. Now I am not sure. I don't race the engine. I don't track the car. .My c7 is a 2016 z52 A8.
Should I bring it to the dealer to havee ir checked for warranty repair, if needed to?
From: Las Vegas - Just stop perpetuating myths please.
DS, well it reads like you are trying to measure the p-rod at some lift other than mid-lift. You want to measure with the rocker arm 90 degrees to the stud when the cam lobe is mid-lift. This is very difficult for beginners as you really need a lifter/follower tool (or solid lifter as mentioned) to find mid-lift of the cam lobe and I think you need a solid lifter/follower tool for this. Yes it needs to be the same height as your lifters. For unique lifters you might need to buy an extra lifter and make it solid with some type of epoxy.
My self I never use checking springs because I use a cheap plastic p-rod checking tool for modest lift cams (0.5") and I can feel when the p-rod is at zero lash. I suggest using a solid p-rod and try to depress the lifter cup with it to get a feel for what it takes to operate the plunger inside your type of lifter. If you notice the vendors sell p-rods in 0.010" increments and mostly 0.20" increments so what I'm saying is close is good enough as long as you have a good pattern on the valve tip and the roller does not reach the edge (but yes the more centered the better).
Too many owners follow that you-tube video that describes the 90 degree action/technique but leaves everyone hanging on how to determine 50% lift on the cam lobe (can't recall that arrogant jerks name now but he was always trolling on this forum for business).
DS, well it reads like you are trying to measure the p-rod at some lift other than mid-lift. You want to measure with the rocker arm 90 degrees to the stud when the cam lobe is mid-lift. This is very difficult for beginners as you really need a lifter/follower tool (or solid lifter as mentioned) to find mid-lift of the cam lobe and I think you need a solid lifter/follower tool for this. Yes it needs to be the same height as your lifters. For unique lifters you might need to buy an extra lifter and make it solid with some type of epoxy.
My self I never use checking springs because I use a cheap plastic p-rod checking tool for modest lift cams (0.5") and I can feel when the p-rod is at zero lash. I suggest using a solid p-rod and try to depress the lifter cup with it to get a feel for what it takes to operate the plunger inside your type of lifter. If you notice the vendors sell p-rods in 0.010" increments and mostly 0.20" increments so what I'm saying is close is good enough as long as you have a good pattern on the valve tip and the roller does not reach the edge (but yes the more centered the better).
Too many owners follow that you-tube video that describes the 90 degree action/technique but leaves everyone hanging on how to determine 50% lift on the cam lobe (can't recall that arrogant jerks name now but he was always trolling on this forum for business).
This is a 6 year old thread someone with a C7 resurrected by posting in by mistake. I fell for it myself last week
Last edited by augiedoggy; Dec 26, 2020 at 03:49 PM.
Checking springs too strong!
