[alfa] Starter drive gear measurement

[Jon Pike <jhpike@xxxxxxx>]

OK,  I have a unususal request.

I'm looking for somebody(s) who has a known 72-74 era starter (the one 
meant for the 130 tooth ring gear) who could measure the drive gear with 
a caliper for me.

I have a 130 tooth ring gear (due to my rebuilding an early motor) and a 
131 tooth starter.  I also have a couple of starter drives I got at a 
swap that seem slightly larger than my 77 starter's drive.

Since we're talking a difference of .987" to .997",  I'm wondering if 
all I'm seeing is wear.

So, if anyone has a known 130 tooth starter handy and a pair of 
calipers,  it would be great if you could measure across the two widest 
teeth and let me know what you found.  Since the 9 tooth "star" ends up 
without two teeth exactly across from each other, you can't measure true 
diameter.
Measuring across the widest two is the reference I've been using.

This will be nice if we can nail this down,  then it will be possible to 
pick up an unknown starter and determine what ring gear it will be happy 
with.  From what I've found, you can't do this just by reading part 
numbers,  even Bosch dosen't seem to know what the old numbers mean 
nowadays.

I'm kicking myself for not measuring diameters and tooth dimensions on 
the early gear (have the transmission back on the engine now) but can on 
the 131 flywheel.  I'll try to guestimate the size difference of that 
one tooth, and what it will do to the diameter and therby radius of the 
drive gear, as a cross check.

Jon
77 Spider
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