<VV> Rebuild II rusty fasteners

[Frank DuVal]

BTDT. Working on older things always means dealing with broken 
fasteners, it is just part and parcel of repair work. I would think even 
west coasters have exhaust hardware rust together. The left handed drill 
bits are especially helpful on moderately stuck bolts. You can get them 
from the Snap-On-Tools truck jobber, just ask your friendly mechanic 
shop when they will stop by again (typically every week). I'm sure other 
cheaper sources exist, I just don't know them. With regular right hand 
bits the object is to center punch the hole acurately and drill a small 
(3/32") hole to get a center pilot going. Slow speed, lots of lube don't 
push too hard and break the bit. Concentrate on getting the pilot hole 
straight. For larger bolts, you could start larger (1/8"). Then step the 
drill bit size up gradually until just the threads are left. sometimes 
you can then uncoil the bolt threads leaving the hole threads. Sometimes 
the hole threads do not live through this, then it is time to tap the 
hole for a larger fastener. This is a last resort, but usually OK for 
valve cover bolts. It would not be OK for head stud holes unless you 
have a source for larger head studs! But, rather than larger fasteners, 
I usually use Helicoils thread repair kits and use the original style 
fasteners. Most extractors have a bad feature that they expand the 
broken bolt to get a grip. This adds to the locking force. I avoid their 
use.

Don't let this discourage you. Just be happy your are not doing it for a 
living and having the customer balk : "what do you mean you are charging 
me 4 hours to replace a valve cover gasket! The book only says a half 
hour! Thief!"

Frank DuVal



Stephen Upham wrote:

> Had a bad Corvair day today.  After all the blood, sweat, time and 
> money that I (and others) invested to get this engine rebuilt (twice) 
> not to mention the brake overhaul, gas tank replacement, and steering 
> system work, I've been gut punched by something as simple, yet 
> daunting, as a broken valve cover bolt broken off in the head that, 
> despite all of my efforts today (three trips to Home Depot, one to 
> Auto Zone, one to O'Reilly, and another to PEP Boys, five broken drill 
> bits, and two broken bolt extractors for a total of six hours labor) 
> finds the bolt (what's left of it) still firmly attached to the head 
> and apparently ready to resist all efforts to remove it short of 
> drilling it out and destroying the threads on the head in the process.
>