I'm certain you're right, the Triumph bolts in general seem quite strong.
Problem is that many of them have been used and abused over the years.
replacement parts from any of the major suppliers are NOT nos parts but have
been made somewhere else--could be almost anywhere, but it's likely that
English is not the primary language.
Torque a bolt to near yield, run it for forty years, retorque a few times in
a racing motor and I don't have a clue what you've got.
I don't use ANS bolts or "aircraft" in general, expcept for specific
applications where I know what I'm getting into. ARP makes very good stuff,
intended for racing. It's relatively cheap (compared to a failed bolt). I
haven't had very many bolts fail, but the ones that have cost me dearly. Two
thousand bucks worth of transmission for a couple of flywheel bolts, six
grand worth of radical motor (Kawasaki) for a failed rod bolt. Lots of
broken motorcycle stuff, including losing the entire front end coming off a
jump when the fork damper bolts broke off at the heads.
I like good bolts. If nothing else they are really pretty.
-----Original Message-----
From: owner-fot@autox.team.net
To: roadandtrack@hypermax.net.au; FOT
Sent: 4/18/2005 6:34 PM
Subject: Re: stronger main cap bolts
Great I am really at ease now When it comes right down to it Ive run
about
50 events on only 2 different motors and the stock bolts have been fine
I
was discussing this thread with a friend today and his opion was
itan'tbrokedon'tfixit
----- Original Message -----
From: "Terry and Cindy" <Roadandtrack2@hypermax.net.au>
To: "'rob'" <19to1tr6@comcast.net>; "FOT" <fot@autox.team.net>
Sent: Monday, April 18, 2005 9:17 PM
Subject: RE: stronger main cap bolts
> Interesting reading
>
> Does anyone have any real data on the yield strength of the bolts
being
> suggested versus stock ones??.
>
> I have been caught before. I am using some Mitsubishi conrods in a
> stroked 2 litre GT6 racer. I had their bolts tested to find they are
the
> same yield strength as the fancy ARP ones.
>
> I have built dozens (maybe hundreds) of road & race triumph engines
over
> 30 years and never seen a main bearing bolt fail. I've tossed out
quite
> a few from thread damage or other visible defects, but the majority
are
> fine.
>
> Further, with regards to 'aircraft" bolts, many are a grade of
stainless
> steel which can be quite brittle, and are not suited to this type of
use
>
> Does anyone have any real data to share??
>
> thanks
>
> Terry O'Beirne
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