<VV> Changing gear ratios in Corvair transmission

[Clark Hartzel]

Ken at Deltawerkes asked about this.  To change a gear ratio one gear
has to be bigger or smaller and the mating gear has to be whatever pitch
diameter fits the center distance.  You can't change a gear ratio by
altering the number of teeth in the same pitch diameter.  For example,
if two 25 tooth gears mesh you have a 1:1 ratio.  If you drop one gear
to 20 teeth the other has to go up to 30 teeth to fit the center
distance.  You now have a 2:3 ratio.  A slip-on gear as on the main
shaft is easy to make new.  The problem is the counter gear which is all
one piece.  Very expensive to make that new.  It is much easier to
change the ring and pinion gear.  If you are building a tour car that
sees a lot of freeway driving, put a 3.27 or 3.08 ring and pinion in it.
If you want to go drag racing put a 3.89 or 4.11 in it.
Clark Hartzel (retired machine tool engineer)