[DeTomaso] pushrod length

[Will Kooiman]

Or, just use math with a pushrod that's close.

It's something like this.

1.  Find the threads-per-inch on your adjuster.  I believe mine where 24.
2.  Use a pushrod that's as close as possible.  If you don't have one, you could buy 1 pushrod, but if you're going to do that, just buy a length checker.  They're really cheap.
3.  Find the length like you normally would - rotate one full cycle, look at the witness mark on the valve, I like to use masking tape to mark the tips.
4.  Use the adjuster like you would an adjustable pushrod.  In other words, when you would normally adjust the adjustable pushrod up/down, adjust the rockers instead.
5.  When you're done, count the rotations up or down to zero lash (solid) or your preload (hydraulic), multiply by 1/24.  You need to count partial rotations too, but probably one in 1/4 increments.  Plus, you have to multiply by the rocker ratio.

I might have this slightly off, but you should get the picture.  I have to think about it to make sure it's multiply vs. divide, etc.

I have a pushrod length checker, but it was too long for my Viper, so I used that math.  It was spot on.

Btw, I also adjusted until the dry hydraulic lifters bottomed out - and then when I had my number, I subtracted the turns to get to the proper preload.

On 2/17/21, 7:28 PM, "DeTomaso on behalf of Mike Drew via DeTomaso" <detomaso-bounces at server.detomasolist.com on behalf of detomaso at server.detomasolist.com> wrote:

    Guys,

    While it’s a great idea to make a tool if you are building an engine in your garage, if you are in India and you are paying mechanics in Spain for their time, it’s much cheaper to buy a tool ready-made. :)

    Mike

    Sent from my iPad

    > On Feb 17, 2021, at 16:25, Garth Rodericks via DeTomaso <detomaso at server.detomasolist.com> wrote:
    > 
    >    Oops!  Guess I was a little late to the party.  Everyone else already
    >   suggested this.  :)
    > 
    >   On Wednesday, February 17, 2021, 04:20:30 PM PST, Garth Rodericks
    >   <garth_rodericks at yahoo.com> wrote:
    >   As Julian suggested, it's simple to make a tool...   Just use a tubing
    >   cutter to cut one of the old pushrods in half, tap the inside of each
    >   half and use a short length of threaded rod with a couple of small jam
    >   nuts.  They can rotate the engine sot he pushrod moves through it's
    >   entire stroke and adjust the pushrod length until they find the optimum
    >   length to properly center/seat atop the valve tip.
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