What are the .23 and .174 marking on the adjustment end if the rockers. The markings are vary from rocker to rocker. Also, can you tell what the rocker ratio is by the numbers?

 

Those are low ratio, 1.43:1. I don't know about the numbers.

 

Those 23 & 174 are probably just the mold numbers..

 

I agree. The end numbers can serve to ID individual rockers if something special is being done.

Once when I had too little to do, I went through about 3 sets of rockers, checking each one on a thing rigged up to use a dial indicator on, and find the 16 rockers that were as close to the advertised ratio as possible. On the 1.43s, some ratios were actually as low as 1.33.

 

Thanks for the information. The numbers vary so in hope that is not the case. My first though was weight but they vary too much for that also.

 

My main point is informational only, that there is a surprising variation from one rocker's ratio to another. Call it trivia.

More trivia and more variances: measure the ball end of your adjusters for diameter, with a caliper.

 

When you check the ratio, you need to make sure it is with respect to the ball of the adjuster screw and the surface that contacts the valve. Anywhere else and you probably won't get accurate results. You very well may measure a small variation but once they are installed, the effective ratio may be a lot different and could vary quite a bit.
When dealing with old sets, wear on the valve end will affect the ratio because the adjuster screw must be moved to compensate. Similarly, a sloppy valve job or a mixed set of pushrods or a poorly made set of pushrods will have the same affect because in each case the adjuster screw will have to be moved from it's intended position.
The angle of the screw with relation to the shaft bore and valve contact surface causes the ratio to change any time the adjuster screw is moved, for any reason. The ratio will increase when as the screw is loosened and will decrease as the screw is tightened. So, if you run the longest pushrods possible for a given combination of parts, you will get the highest ratio possible for any given rocker arm.
Geometry is another factor that does affect the effective ratio, but assuming that there is a quality valve job, and quality parts throughout, I don't think it matters because although the ratio may not be the same that you measured when checking, it should remain consistent from valve to valve on the engine. Geometry is a whole other can of worms.

 

When you check the rocker ratio of 50 or so rockers, using the same valve, the various variables dont exist.

 

They do exist. Using the same valve does not eliminate any variable with the rocker arm. The variables that still exist are:

Rocker arm wear. Was every rocker worn the same amount? Probably not. That is a variable which will affect the ratio.

Machining tolerances. This would be the most significant cause of variation and will be present in anything, and particularly apparent in mass produced parts. This is why the adjuster screw and rocker arm must be checked as an assembly.

You would need a way to simulate lash in order to position the adjuster screw approximately the same each time. Without doing this, the adjuster screw becomes another variable. Proper lash adjustment should eliminate rocker wear from the equation. The valve used for the test must always return to the same closed position. If it does not, then it is the same as changing the valve train geometry which will change the ratio.

If you used the ball of the screw with the screw in the same position each time, the same shaft, and a valve, the results should be pretty accurate.

Have a look at Ted's device.
Eaton Balancing » Altering Rocker Arm Ratio By Varying The Length Of The Pushrods

 

Here is more trivia, I there is a Porsche turner in Dallas who reprograms the black boxes to find the most potential of a engine. They have found production engines have up to 10% variation in potential output and Porsche detunes them all the the same level with the black box.

I am pretty sure Ford's quality control 50 years ago is not a good as Porsche's is today.

 

Like I said, I went through the exercise to find a set of 16 rocker arms that were as close to the spec as possible. I guess the reason as to why the rockers were or werent close to spec wasnt important. But with zero lash set using the dial gauge, and with each rocker on the same valve succesively, the difference was in the rockers. I did note that several rockers which were not original but aftermarket were among those relatively far off.

 

I'll suggest that the best way to measure a ball, or cylinder, is with micrometers. Calipers are less inclined to get positioned properly for an accurate reading.