<VV> flex plate / converter maximum torquage

[djtcz at comcast.net]

snipped and bottom posted 

-------------- Original message -------------- 
From: cfm <cfmann at yahoo.com>
Subject: <VV> dreaded flex plate bolts
To: Virtual Vairs <virtualvairs at corvair.org>
Message-ID: <208976.90263.qm at web36805.mail.mud.yahoo.com>
Content-Type: text/plain; charset="iso-8859-1"

hi again, same issue revisited, I apologize in advance for any redundancy. 
I tore into the engine shrouds and removed the front shroud again to gain access 
to my loose flex plate bolts.
As some of you might recall, a month or so ago, I made this repair back then 
too. The only rookie mistake I made then was not to torque properly and lack of 
thread lock. Also, this car is not currently being driven daily or occasionally.
I had to come back to this issue, because after changing the oil, I started the 
car and ran it up to normal operating temperature. I got a little silly with 
revving it during this period and whammo, the problem resurfaced (rattling). I 
new right away what happened. So here I am back at it, only this time I want to 
it as right as possible. However, I am trying to understand why this may have 
happened again.
It was suggested recently (through VV) that I replace the bolts because the 
threads may be "stretched" or the bolts have just lost holding power. But as I study the 
amount of space I have, its unlikely I will be able to take the old ones out and 
replace with new. The special nut on the backside also poses a problem as if I 
remove said bolt, the nut will fall and then where am I. Also when I look 
closely at the nut, it appears to have a two tiered surface, leaving me to 
believe that these nuts were brazed to the mounting plate adjacent to the flex 
plate, is that a correct assumption?
Last, I can't seem to get my torque wrench in close enough to perform this task 
correctly. The only thing I can think of during is removing the fan shroud, or 
two, going by "feel" without torque wrench. In the shop manual, it calls out 
30-40 ft. lbs.
Any tips or suggestions would be greatly appreciated.
Chris Mann

Check that spec, and the thread size. Sounds high.  The bolts that hold the clutch cover (often called pressure plate) to the flywheel  in a manual trans are 5/16-18, and only get 15-20 lb-ft in the 1965 chassis manual

I've torqued some other like sized fasteners up using a torque wrench, then snugged them a little more by hand to develop a feel for it.  A bolt with its head in a vice, 6 or 12 flat washers and a nut would make a torque sample.  Humans are not born with a "feel" for torque. I know an excellent machine tool digital-read-out technician.  He picked up the vintage dirt bike hobby, and bought a CZ, a make with a well deserved reputation for stone-ax reliability.  He swapped some motor parts around, and tightened his bike's magneto nut to what "felt" right to him. First race the magneto slipped on the crankshaft, and tore up the key and shaft taper.

Dan Timberlake 
Westford, Massachusetts, USA