Pushrod length checked with lifter pumped up?
Thread Starter
Intermediate
Joined: Jan 2023
Posts: 43
Likes: 5
From: New Zealand
Pushrod length checked with lifter pumped up?
I'm in the process of measuring my pushrods and have a set of brand new Johnson lifters. Since the short travel lifters are brand new does that mean that they are fully compressed by the factory spec of 0.058" and that if I take my push rod measurement in there current un-oiled/pumped up state I can simple add preload minus full travel (0.030-0.58= -0.028) to the pushrod length measured at zero lash to get the required pushrod length? Or should I measure them pumped up and minus the preload? How do I take into account the fact that a different sized pushrod end will potentially sit differently in the lifter?
Sorry for the noob questions, I have done a search on here and on google but have come across a wide range of answers. Thanks.
Sorry for the noob questions, I have done a search on here and on google but have come across a wide range of answers. Thanks.
Uneducated autodidact
Joined: Feb 2001
Posts: 5,413
Likes: 252
From: West of the Sabine, Texas
You should be able to take the new lifter(s) and compress them on the bench with a stock pushrod if they are new and haven't been soaked in oil. In that case, you should be able to use an adjustable pushrod to take out all the slack, measure the pushrod and add the preload. If they won't compress on the bench due to oil soaking you will have to disassemble them and remove the oil so that you are only pushing against the lifter spring when measuring. Hopefully I've explained it properly.
