measuring pushrod lenth

[87-TURBO-T]

so basically, i adjust the pushrod to zero lash, then add about .030 for preload? thanks

 

[m233roller]

Yup.

 

[87LtdT]

Don't forget to have the rocker lever's adjusting screw at the correct location when doing so.

For example, HS recommends 2 threads below flush from underside of the lever as "optimum". These are .050" per thread. The lifter preload is recommended at .025" ...which is 1/2 of a thread. So when I will measure push rod length I will do so with the adjusting screw protruding 1.5 threads below flush.

That way, during actual installation, after the .025" pre-load is set the adjusting screw will be 2.0 threads below flush...the optimum location for HS rollers.

HTH's,

Bob

 

[Mike Licht]

Just remember that pushrods are measured on the radius not end to end. So they are tough to order correctly. If you get the tool that looks like an adjustable pushrod but is marked in .050 increments getttng the correct ones is a snap. We have the correct tool for most Buick applications and most size pushrods we can get same or next day. Pushrods are stocked in .025 increments.
Mike

 

[87LtdT]

I did not know this Mike. I made my own length checking tool by threading and inserting a screw into both ends of a push rod I'd cut in half. Added a couple of nuts to tighten and "set" the length. Am about to measure what I need and planned to take the "set" length push rod to a machinist friend with calipers long enough to measure.

Of course we will only be able to measure from the flat (where the hole is) on one end to flat on other. Should I then add the distance that is missing because of the oil hole (times 2 for both ends)??

Asked another way: Should the distance measured be from one spherical end to the other without any oil hole??

Asked yet another way: Does the real push rod length checking tool have a hole in it, or is it a fully spherical end??

Thanks...a lot. Bob

 

[Mike Licht]

It has a hole in it, as I remember the tool they use at the pushrod factory (local to me) measures them 120* on the radius. I know that sounds crazy but that is what they told me. I know if I measure end to end it does not agree with their measurment.
Mike

 

[87-TURBO-T]

Don't forget to have the rocker lever's adjusting screw at the correct location when doing so.

For example, HS recommends 2 threads below flush from underside of the lever as "optimum". These are .050" per thread. The lifter preload is recommended at .025" ...which is 1/2 of a thread. So when I will measure push rod length I will do so with the adjusting screw protruding 1.5 threads below flush.

That way, during actual installation, after the .025" pre-load is set the adjusting screw will be 2.0 threads below flush...the optimum location for HS rollers.

HTH's,

Bob

they are stock, non adjustable

 

[SNOWBIRD]

120 on the radius ....now I need a degree in phsics or something.

 

[87-TURBO-T]

mike, do you have the 8.675" in stock?

 

[87LtdT]

Mike, can you be clearer where push rod length should be specified from??

I'm guessing if we draw a line down the centerline of the rod...the measurement made by the factory is taken at a circumference that is 60 degrees either side of that centerline. Is this correct??

If you are unsure is there a phone number I can call?? I want to get this correct.

Bob K

 

[SNOWBIRD]

search on net....valve geometry ...will answer all your questions.