Good Morning Lawrie,
Have you recently caught something from Ed? In answer to your first question
regarding experience, I have only some 30 years work experience under my belt
involved in metrology and non-destructive testing, including 3 patents and four
copyrights for automated test and measurement instrumentation and software. I
have rebuilt a mere 25 British engines during the past 17 years. Thanks for
asking, but my statement regarding head studs was based not entirely upon
experience, but on original MG reference materials. On to your next questions.
"How many times can used head studs be re-used safely"...
The answer: until they are damaged, worn out or no longer meet the criteria that
determines suitability.
"how, by looking at an engine that you've just taken apart for the first time,
can you determine how many times the studs there have already been re-torqued?
The answer: you probably can't.
Books have been written on the subject of fasteners, and I will not bother
writing another. If you or anyone else wants more information, please send an
e-mail to me off-line.
Your questions are somewhat nebulous: it is less important to know how many
times a head stud has been reused then it is to know if it should be reused at
all. According to my limited reference materials including original workshop
manuals and parts lists for MGA, MGA Twin Cam and MGB studs that fasten the head
to the block on these engines, do not require replacement during a rebuild
unless the threads have been damaged in some way. I chose to adhere to MG's
recommendations, check the original and stay with it if it passes inspection
especially when the available replacements are known to be of inconsistent
quality. Of course, you can follow whatever course you chose to take.
Jim (the elder)
I've rebuilt engines purely for the love of it
Lawrie Alexander wrote:
> May I ask on what experience you base that statement, Jim? And the following
> btwo questions would also seem important - How many times can used head studs
> be re-used safely, and how, by looking at an engine that you've just taken
> apart for the first time, can you determine how many times the studs there
> have already been re-torqued?
>
> Lawrie
> British Sportscar Center
> (Who has no Ph.D but forty years of engine building experience)
>
> -----Original Message-----
> From: James H. Nazarian, Ph.D. <microdoc@apk.net>
> To: Baker, G. <gbaker@customcpu.com>
> Cc: MG Board <mgs@autox.team.net>
> Date: Tuesday, January 16, 2001 5:52 AM
> Subject: Re: Head Studs
>
> >This is true with certain cars, particularly newer American makes, but it
> >is not true of pre-1980 MGs, or Healeys. We definitely can re-use studs.
> >
> >Jim
|