<VV> Crank gear issue

[ntcagp at sbcglobal.net]

Good info Seth – I looked at the tool and came to the same conclusion – however – I have four bolts broken off inside the gear, and the other two holes are useless. Now how do I use this tool? I’m not sure of the grade of the broken bolts, so can they be drilled out? I fear #3 is my best option at this point. I did once split a case to replace a crank with the heads still on, but still lots of work, and the remainder of the engine remains a mystery with this process. As an extra bonus, the po re-installed the transaxle with the lower driver side of the case missing – broke clean off!
thanks again,
Garry

From: Sethracer at aol.com 
Sent: Tuesday, September 04, 2012 11:23 PM
To: ntcagp at sbcglobal.net ; virtualvairs at corvair.org ; fastvair at yahoogroups.com 
Subject: Re: <VV> Crank gear issue

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