Disaster Averts Disaster?


I have had "Mr. Chevy" for 10 months now and I am finally about cought up on my list of things to do. I have taken my time to do things right in the restoration and documentation of the car. In general the car has cleaned up better than expected. I used a cleaner wax for every hard surface on the car, paint, glass, chrome, and stainless trim. It was a lot of work but it left a beautiful finish that was hidden under a film that had accumulated over the years. The interior of the trunk was repainted exactly the way Van had it back in the 60's. The interior needed dusting and vacuming and all the glass and chrome in it was also waxed. The engine compartment got a good cleaning and all the rubber hoses on the engine were replaced. The fiberglass front end was repaired and the frame work straightened so it sets squarely on the car and can now be tilted again. The windshield and drivers door glass were also replaced from being damged in the accident. I had the car for two months before I had completely checked the engine over to be sure it was safe to start it. It was another couple of months putting the drivetrain back into shape, the transmission needed a new case and tailshaft and a new chrome driveshaft was made. I have driven it quite a few times now, still learning the quirks of mechanical fuel injection, such as how to shut it off and how to restart it.

I don't plan to race "Mr. Chevy" but I would like to be able to make some full power launches and go through the gears. Which brings me to the next phase of restoration. Since the car had a heavy duty Pontiac driveshaft and u-joints in it I am not convinced the rear u-joint just exploded. Van had mentioned to several people his theory of the "incident" was the driveshaft was weakened by chrome plating. I don't believe that happened either. Getting the original slicks back on the car help a lot to understand what did happen and what was about to happen the last day it ran.

Van had been running "Mr. Chevy" for several years in its current configuration with a smaller pair of slicks on it. These tires were smaller and did not have the potential for traction that the new set Van just bought. The new pair were wider and when liberally coated with VHT made for traction that would prove disasterous. I am still unsure of what caused the rear u-joint failure. Could it have been a weak or improperly installed u-joint? Was there interference from the crossmember on such a hard launch? The guy who built the driveshaft said another cause of failure on the Pontiac u-jointcould have been breakage or loss of the C clip. The car was shaken so violently that the aluminum housing of the starter was also cracked. When the starter bolts were taken out 30 years later, the starter fell out in pieces. This is the damage that did happen. If the car had launched and made a full power run, a worse disaster may have happened. There is only a half inch or so clearance between the rear wheels and the fender well lip. Under acceleration, all is fine, the ladder bar lifts the rear of the car allowing even more clearance. However, under deceleration, the opposite will happen. When the brakes are applied, the ladder bar will pull down on the body. Even though there is a smooth roll on the lip it is doubtful that the rear tires would have held up under a hard 15 second deceleration from 100+ MPH. Was disaster averted by disaster? Who knows.

I have a smaller pair of slicks that I plan to run when I decide to do so. I am looking for at least 2" clearance between the quarter panel and tire. As far as crossmember clearance, I am still studying that.