Lifter rule
 

Where in the rule book or on line at NHRA is the minimum
.012 plunger movement on hydraulic lifters?:confused: I seen it before
but now I can't find it.
Thanks

Re: Lifter rule
 

This is copied directly from the NHRA Policy and Procedure Manual
This is the actual way the lifter is checked for travel.

1.3 LIFTERS & LIFTER BORES
1.3a HYDRAULIC AND HYDRAULIC ROLLER LIFTERS - Stock
The NHRA Rulebook, under blueprinting states “Stock factory OEM components (unless otherwise
specified) must be retained and remain unaltered (ie: push rods, crankshaft, etc).” An engine combination
listed with a hydraulic or hydraulic roller lifter must remain unaltered (ie: no internal or external
modifications to the stock factory OEM- type lifter). Upon inspection, the plunger must be at or near
the snap ring at the top of the lifter. The lifter will then be compressed in a C-clamp, at which time it
must exhibit down travel, and bleed off oil, thus proving that it uses hydraulic pressure to keep the
plunger from collapsing. (If the lifter is installed in the engine with preload, upon inspection the
plunger must exhibit down travel greater than the amount of preload.) The lifter will also be
disassembled and inspected to verify that it has not been “plugged.”

The key words in this checking procedure are: must exhibit down travel, and bleed off oil, The actual amount of lifter travel may or may not be checked.

Then read the last part about installed lifters with pre load. When you read that what does that tell you about the amount of travel? I think it would tell me it depends on how you install and set the lifter up to work.