<VV> Crank gear issue

[Sethracer at aol.com]

In a message dated 9/4/2012 6:25:34 P.M. Pacific Daylight Time,  
ntcagp at sbcglobal.net writes:

The  three things I have considered (but don’t know the feasibility of) 
are: 1.  drilling and tapping the holes larger.  I am unsure of the hardness of 
 the bolts/gear, so is this possible? 2. Is it possible to change the crank 
 gear with the engine assembled? 3. Complete teardown and start over. 
 
The safe course is Number 3. But - it is a lot of work. #2 is impossible.  
#1 may be possible, depending on how bad the "wallowed out" holes are. The 
stock  holes are (or were?) 11/32 -(24?)  Blue Chip machine makes a nifty 
tool  designed to guide you in drilling out the six holes to 3/8-24 NF thread. 
I just  bought one of the tools from John Sweet at John's Corvair parts in 
PA. The tool  bolts in place with a pair of the 11/32 bolts and presents you 
with a drill  bushing to drill out some of the holes to the 3/8 thread minor 
diameter,  then a guide for the tap to tap them to the larger size. You 
then relocate the  tool and progress around the bolt pattern. The kit includes 
the drill and the  taps - both a leading tap and a bottoming tap. I have not 
yet used it, but it  looks pretty slick. It appears like you could do the 
re-threading with the  engine assembled - but (DUH!) out of the car. The 
mounting holes in the stick  flywheel are already 3/8", so nothing needs to be 
done there, but I can't vouch  for the holes in the PG flexplate mounting 
triangle, but they are probably  3/8". The main point is, it doesn't hurt much 
to try it, just the price of the  tool. If you screw it up?  Well you learn, 
and move on to choice #3. And  you can always sell the tool to an aspiring 
racer!
 
Seth Emerson