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Re: Mechanical Failures

To: WATTSIT2ME@aol.com
Subject: Re: Mechanical Failures
From: "Jack W. Drews" <vinttr4@geneseo.net>
Date: Sun, 26 Nov 2000 14:25:18 -0600
WATTSIT2ME@aol.com wrote:

>
>
> "Old parts that were often questionable when new are reaching the absolute
> limit of their design expectations" True for sure. And you know what else?
> When the same parts are put under such astronomical loading as per the type
> of car noted above, something's going to fail. Cars were driven on tires that
> were high profile, treaded and slid all over the damn place. Same car, low
> profile tires, wide slicks, guess where the load goes? Hello! Something's
> going to break!  I defy anyone to show me photographs of cars, running as
> true competition cars in the 50's and 60's that even come close to what you
> see on some of the Vintage race circuit(s) today.................
>
> Racing? Fine, try SCCA.
>
> Respectfully;  Dean Watts

This discussion comes up about twice a year, and there are as many opinions as
there are people on the list. My one and only contribution to what will surely 
be
a long thread will be to relate my personal experience, to maybe put Jack
Woerhle's comments in perspective:

I have raced a 1961 TR4 for five years. To the best of my knowledge, it was
prepared to comply with 1961- 1963 rules in every regard, including stock rods
and crank, no flares, no bigger carbs, etc. Deviatations from those rules
included a roll cage that attached to the chassis in one more place than the 
1961
rules allowed, and Hoosier Vintage tires, which, it could be argued, are no more
sticky than the Blue Streak slicks that became SCCA legal in 1963, which was
during the production life of the TR series. Please remember that the ONLY tires
currently available for vintage racing these cars are treaded Hoosiers, Dunlops,
and maybe one other brand -- and they all have virtually the same stiction.

As other listers know from discussions ad nauseum, in July 2000 a rear axle 
shaft
snapped, the car rolled three times, and was absolutely totalled. The car had
nearly new axle shafts, using modern steel technology, heat treated, etc. The
accident revealed a design flaw. I believe Kas Kastner said that when they raced
these in the 60's they changed axle shafts very frequently -- every two races or
something like that. Again, to the best of my knowledge, there have been three
other vintage rollovers caused by the same failure.

We have developed a fix that will hopefully eliminate this design flaw,
consisting of retrofitting the rear axle with modern forged one-piece axle
shafts/hubs, distinguishable from the outside only by the lack of the center hub
retaining nut. The conversion is not cheap, but it is less expensive than my
start-from-scratch rebuild.

Admittedly, in some groups the performance modifications are proceeding at a
runaway pace, but I appreciate Jack Woehrle's viewpoint, and I would hope that 
my
type of modification would not offend anyone except my banker.

--

uncle jack

The Attorney General advises that vintage racing may be hazardous to your 
wealth.

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