Anyone ever make a valvetrain geometry checking tool?

Clatter · Post by **Clatter** » Wed Feb 21, 2007 9:39 pm

Here I was thinking again (bad sign)...

What if you took a piece of flat plate, very thin, almost like sheet, but thick enough to stay true, and not get bent...

Then cut a notch out round, and clearance so it would rest on top of the retainer, but not touch the lash cap or the rocker pad (or anything else) during travel...

Have an arm come out and around, with a point on the end, that would point close to the center of the top of the end-bolt of the rocker shaft.

All of this would be cut out of a flat piece, so it would stay in one plane...

That way, when you were at half-lift, it would point right to where you were in relation to the centerline of the shaft....

You would measure the difference between the top of the plate and the top of the lash cap, and then be that far down from center on the end-bolt. Hopefully this would be a small number, and you could hopefully pick a thickness for the plate stock that would match.
Accounting for differences in keeper/retainer depth and lashcap thickness, it would be impossible to have perfect, but hopefully close, and measurable...

you can always tell when you are in the center of a round object, the eye is accurate in this situation.
You could always chuck up the end bolt in the lathe and touch it near center real lightly so there was a nice center reference mark.

It would be cool to maybe make it magnetic, so it stuck to the top of the retainer. Anyone know if titanum is magnetic?

This would only work on one valve per head, like exhaust for #4 on one side and #1 on the other, but would tell the truth.

I'm just here, holding my mouth right, using a straightedge, comparing full lift and closed, holding my mouth a little different, using a mirror and/or a back-light, moving shims around, changing lash caps, sticking my tongue out a little, moving the adjustable pushrod a little more, and thinking there's GOT to be a better way...

70dragbug · Post by **70dragbug** » Thu Feb 22, 2007 7:52 am

Jesel has a tool to check rockergeometry for their rockers. www.jeselonline.com
If you´re a handy craftsman you might be able to make one similar to that.I´ve wondered why some of the other aftermarket businesses haven´t made a tool like that yet - or maybe I´m missing something.

Eaallred · Post by **Eaallred** » Thu Feb 22, 2007 6:26 pm

Just use a dial indicator to rotate the engine over to half-lift. Then check to see if the adjuster is lined up with (depending on the rocker design) either the pushrod or the valve stem. You can eye-ball it pretty well.

A_67vdub · Post by **A_67vdub** » Fri Feb 23, 2007 9:51 am

Something you can make to help lining up the rocker with respect to the valve easier is a simple wedge cut to the same angle that the valves are. If you held the wedge up against the valve cover sealing surface it would give you a perfect line 90degrees from the valve. This is more of a benefit to those with the adjuster on the pushrod side.

Clatter · Post by **Clatter** » Fri Feb 23, 2007 12:48 pm

A_67vdub - good idea...

Anybody know the angle of the valve inclination??

The adjusters on this rocker setup are at the pushrods,
and the rocker is fat enough in this area that it blocks a good view of the screw down towards the pushrod, unfortunately.

Something else driving me nuts is the idea that the ideal geometry would produce the most lift at the valve.
It seems that the best setup so far doesn't produce as much lift as another that doesn't eye-ball as well.