Want to check piston to valve clearance on a 4.3L Chevy w/ 270HR Comp Cam. CC says 270HR will work w/ stock type (dished) pistons... no clearance check required. However, I have installed Sealed Power (SBC) flat tops w/ valve reliefs, engine builder buddy says they're good to go but I still wanna document PtoV clearance for my sanity, curiosity and this engine will be for sale.... but mostly my morbid curiosity.
CC recommends lighter test valve springs w/ stock hydraulic lifters or their solid lifters for the test purpose. CC double valve springs (heavy) for this cam kit are currently installed. I could order and change out the valve springs or install their solid lifters... and wait a week for delivery.... or convert the factory hydraulic roller lifter to solid.
So I stacked AN washers under the plunger w/ spring removed, that brings the plunger socket w/ in 0.020" of the retainer clip. Recommended preload w/ factory roller lifters is about 0.030", CC Magnum lifters is 0.010" so that puts it in the middle.
I'll be using the clay method w/ previously torqued head gaskets and used TTY head bolts just for the test... but they never been run.
I wouldn't bother asking if not for the flat tops, no help from CC and no googles relevant. GRM approved? Better way? Is my thinking flawed here?
