make your own pushrods

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pishta

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Need some 340 T/A length ball/cup pushrods or something custom for that cam/lifter/rocker combo you are running? Look no further than slant six pushrods. They come plenty long and are plentiful in the boneyards for a buck a piece. They have hardened tips and cups barely spot welded into a mild steel tube. Simply cut the ball end off at about 2" and chuck it in a drill press. Get a carbide cutter on a die grinder and carefully grind away the mild steel around the spot weld. When you hit the hardened tip, your sparks will turn almost white, so you know you are on the tip. Move off it quickly and continue until you are sure you are though the tube metal for about 3/4 inch from the ball tip. Take that piece and chuck it in a vice, use a drift to knock the tip out the end and discard tube scrap. Chuck tip in vise from opposite end so you can file the remains of the steel from the ball end step. I files one side until the file ran smooth (on the hardened steel) and then flipped it over and ran it again. Grab the 2 shells with some pliers and pull off, now you got your clean step press in ball tip. Do this 15 more times. Mock up your valvetrain and measure how long your new pushrods need to be. Cut the slants to size minus the length of the ball tip (.175) and drive the tip into the rod by tapping the cupped end with a brass mallet over a piece of cardboard or some other material so the ball end does not get damaged. It takes a fair amount of tapping to get it home, very tight fit. Dont try and use heat to expand end before you tap it in as the end will weaken and bend (I bought 17 just in case, smart!) It took me about 2 hours to do 16 but I was popping them out in 5 minutes per rod toward the end. Mind you these are mild steel 5/16 stock grade pushrods, the majority of the aftermarkets are 3/8 Chromoly, much stronger but if you are just putting some adjustables on your mild build, these should work as good as 273's. Sorry for the terrible pics, cheap a$$ videocam snapshots. MP used to sell this same press fit kit, raw cup pushrods and tips.
 

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Great Info Pishta, just as an addition..

The method of removing the ball from the pushrod tube and shortening the tube works with (some) after-market pushrods as well,, only the ones I've trimmed weren't welded,, just friction fit.. so by putting the hardened ball in a vise,, and just a few seconds of propane heat on the tube,, twist and pull..

I use the valve tip refacing tool on my valve refacer to square the ends,, and it allows you to remove material a thou at a time,,

I'll post a pic of the simple jig I made for checking the tube length before re-unstalling the tip..

hope it helps..
 
very nice info. did you check the length of each one with a dial caliper for consistency?

My dial caliper goes to 6 so I couldn't measure the OAL, but standing them all up on a granite tile showed them all about within 1mm with one a little shorter. If I do another set, I'll use my chop saw and a jig. Does your valve grinder have a lifter attachment? Saw an old ,manual for one that had an attachment to regrind lifters, pretty cool.
 
The tubing is pretty easy to cut with hacksaw, about 10 strokes and you are through, dress with file and your good. Tube cutter will work harden the tip, possibly splitting the tube when you drive the tip in?
 
Here's the pic of the jig for measuring shortened pushrods,, make your first pushrod,, then bend jig to fit,, and trim till the pushrod just fits 1/2 way thru the jig,.. easy enuff,, you get a "knack" really quick,,

If you bend and trim the tool "squarely",, it can help you "square" the cut..

It's nice if you have access to a valve refacer... but
 

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Good info. Just gotta be careful and have patience.

It might help to put the ball ends into the freezer for a day before trying to tap them back in!
 
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