Measuring Pushrods

[Bolted to Floor]

Measuring Pushrods

Working to get this engine assembled.
I made a checker by cutting one of the stock pushrods, threading the ends, and joining with all thread rod. Used the same head on both banks with the head gasket in place and center head bolts snugged. Using Morel 5325 lifters, Comp Hydraulic roller, and non-adjustable rockers.

Spent the morning taking measurements.
With a pair of lifers in place, I rolled the cam till both had opened and closed then another 90 degrees to make sure I’m on the base. I did the intake and exhaust on each end of both banks. Installed the checker then adjusted out till the rocker arm was snug against the valve tip with some resistance for the pushrod to twist. I did all of them twice to see the repeatability.

   Intake  Exhaust 
1. 8.707   8.711
    8.707   8.712
4. 8.688   8.719
    8.690   8.721
5. 8.685   8.720
    8.686   8.721
8. 8.704   8.703
    8.704   8.705

Are the measurements close enough to order one length pushrod for all?
How much length should be added for preload? I found nothing on Morels website and .050 to .100 on Comp’s.

Thanks for the help

[blykins]

Add .060" for preload. 

I would order a 8.690" + preload length for your intakes and an 8.720" + preload for your exhausts. 

Keep in mind that you will need a 3/8" ball for the rocker arm side and a 5/16" ball for the lifter side.  Is that how your checker is setup?

[Bolted to Floor]

Brent, no, the checker was set up from old push rod with 3/8" ball on both ends.

What can that do to the measurements?

[cammerfe]

It seems that a 3/8ths ball won't fit properly in the socket on Morel lifters. The ball is most likely setting on the edge. You might try asking Morel how much difference it makes. Or get a PR with 5/16ths balls and make up a composite checker.

KS

[blykins]

It will change the dimensions.  A 5/16" ball end on a pushrod will sit down in the cup lower than a 3/8".

You will need to modify your length checker if you want an accurate measurement.

[Bolted to Floor]

This is why I ask questions, I'll get this figured out this week. Thanks for the responses.