Custom made Adjustable Pushrods

[BlackAce]

Alright guys how do YOU make an adjustable pushrod?

I went to the local hardware store and bought two taps one was 1/4" 20NC and the other was a 1/4" 28NF and I bought a stud. I cut the pushrod in half tried threading the first one using the 1/4"28F and was about half way done when I snapped the tap.

Tried it again with the 1/4" 20NC and was about 3/4 of the way done and snapped that one!

They weren't cheap $6.50 a piece and were made by Irwin. Did I buy cheap taps or am I doing something wrong???

[rusty duster]

did you drill the push-rod with the correct bit first?

[dwc43]

Originally Posted by BlackAce

Alright guys how do YOU make an adjustable pushrod?

I went to the local hardware store and bought two taps one was 1/4" 20NC and the other was a 1/4" 28NF and I bought a stud. I cut the pushrod in half tried threading the first one using the 1/4"28F and was about half way done when I snapped the tap.

Tried it again with the 1/4" 20NC and was about 3/4 of the way done and snapped that one!

They weren't cheap $6.50 a piece and were made by Irwin. Did I buy cheap taps or am I doing something wrong???

You don't make them, you buy them from Comp Cams. You only use them to check your geometry and such too. Not really made for use in an operating engine, especially for a performance engine.

[pishta]

Well, you only need about .250 travel on an adjustable pushrod as you are only checking your rockers or pedestals. Get a stock pushrod and cut an end off close to the original ball. Get a machine screw (the kind with the half spherical head) with a thread diameter close to the ID of the hollow pushrod you just cut. Drill and tap 1/2 inch of the pushrod and run the machine screw into the rod. Now you have 1 adjustable pushrod. Use it to get your preload or rocker/pedestal height right, measure the end to end and order a set from anyone, like Manton ($$$) Or go cheap like me and but a set of stockers that are longer than what you need off Ebay. Make sure they are 2 piece pushrods. Chuck the pushrods in a lathe and turn the rod down where the tip is press fit until it comes out, collect all the tips. Cut the pushrods down to your new length minus the length of the tip that extends out of the pushrod. Press the old tips into the newly cut pushrods. Sometimes I got way more time on my hands than money I got a set of used 7/16 Manton ball and socket pushrods from a BBC for my 451 mechanical valvetrain and cut them down for less than 50 bucks.