Measuring for push rod length

[dsommer]

Ok, I need some help. I’m in the process of installing the heads on my engine (TFS 23deg) and was wondering how you go about measuring for the push rods. I’ve got a push rod length checker. My questions are:

 

1. What is ZERO lash?

 

2. When checking length what position should the rocker arm be in TDC, Intake stroke, compression or power stroke? (I’m guessing TDC)

 

3. Where should the rocker arm be positioned on the stud? Screwed all the way down (bottomed out?)Or backed off 1 or 2+ turns?

 

4. Should I be taking the measurements with a feeler gauge in place (at the valve tip) for clearance? (I’m guessing yes here)

 

Thanks in advance for you help, thoughts and advice.

 

David

 

My set up

350 ci .030 over

Speed Pro hyper coated pistons

Eagle rods

TFS 23 deg heads

Comp cams mech roller, CAT roller lifters

Scorpion roller rockers 1.5

ARP bolts