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The problem is twofold. It is weight and it is size which of course is
surface speed. The larger the diameter the higher the surface speed. To
make the best of the bad rules and posssiblity of keeping everything
togeather I used an aluminum clutch from a Porsche and an aluminum
flywheel. I made a steel hub to fit over the crank with an interference
fit then bolted the flywheel to the hub. This combination gave a TOTAL
weight of 13 pounds. Were I to do this again I would go to a multiple
disc clutch. Then you would have the light weight AND the small
diameter. To reduce the largest diameter weight I even removed the ring
gear teeth in specific spots as I knew the engine always stopped in
certain areas and I could probably get away with it. Lots of work to
not much benifit. We then turned the engine to 7500 to with pretty good
reliability. The rpm range of the torsional vibration in the crank can
be moved around but is always there. The crank in the TR-6 has no
overlap and thus is a whippy devil. I made the weights as light as
possible and this gave a problem at about 4400 RPM again at 6100 RPM and
then the last vibration was over 8000 and was not of importance. This
third vibration by the way was so severe it was off the page on the pen
recorder. The biggest problem we had was holding the engine revs at the
proper amount on a yellow flag or the pace lap to not be in the range of
the vibration. I figured out that light was good by the simple theory
that if I tooled off the flywheel to nothing, then what could fall off.
NOTHING. Therefore light is good. I would like to add that when we
whipped the clutch flywheel problem then the torsionals went to the
other end of the crank and broke the timing chain, we fixed that with a
double row, then it actually sheared the camshaft bolts to where we had
to add another bigger bolt to keep it all intact. Worth doing though,
we WON. Made 252 bph at 7900 rpm in 1972.Boy this stuff is old isn't it.
David C. Wingett wrote:
> Kas
> Thanks for your response. Yes, I have also had a fly wheel
> come lose but, not disconnect ( last lap of the last race, fastest lap
> of the season). Now, with the ATI balancer, and all the other
> balancing work done, shouldn't that take care of any odd
> vibration...? The Tilton and Quarter Master button clutches are very
> state of the art & balanced to a Bone. The only problem I would see
> is finding a source for the flex plate, using a stock ring gear (of
> course it would have to be CUSTOM made, every thing else is) and
> calibrating a throw out bearing to match the clutch. David W.
>
> -----Original Message-----
> From: R. KASTNER <kaskas@earthlink.net>
> To: David C. Wingett <elkhorn@megsinet.net>;
> fot@autox.team.net <fot@autox.team.net>
> Date: Thursday, March 11, 1999 11:25 AM
> Subject: Re: clutch/flywheelHaving had just a big bunch of
> history with the TR-6 enigne and flywheels and clutchs
> flying off, making a installation with a light flywheel and
> the lightest smallest cluch makes a significant difference
> in the durability of the crankshaft and the available rpm.
> When making the flywheel (aluminum) have the center hub as
> deep as possible with about a .002" interference fit. This
> hub should then go onto the crank almost touching the seal.
> The problem is that the flywheel actually wobbles as the
> vibration of the crnakshaft is transfered to it and this
> movement is then trying to PRY the flywheel off the crank.
> When you lighten, reduce the size of the clutch you reduce
> this movment by about one half. I nmeasured all this on the
> dnyo with a oscilloscope and potentiometers For the fitting
> you then heat the flywheel and it will slide onto the crank
> end. I also drilled and taped the end of the crank for FOUR
> more bolts. Use bolts that are HARD not just strong. By
> hard I mean bolts that have a very limited stretch before
> breaking. Bolts that are stong and stretch allow the
> flywhell to slide around and wobble but the bolts don't
> break. Too bad, cause you are still a DNF.. Machine bolts
> such as used for hold downs in shop machinery such as a
> mill are hard and do not stretch. Kas Kastner
>
> David C. Wingett wrote:
>
> > Since the question of clutch & fly wheels has arisen,
> > I'm wondering if anyone has tried putting together a small
> > button clutch (Tilton or Quarter Master) with a flex
> > plate,on a TR-6 ? I can only imagine the rotating mass
> > coming down to near nothing.
>
>
>
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The problem is twofold. It is weight and it is size which of course is
surface speed. The larger the diameter the higher the surface speed. To
make the best of the bad rules and posssiblity of keeping everything togeather
I used an aluminum clutch from a Porsche and an aluminum flywheel. I made
a steel hub to fit over the crank with an interference fit then bolted
the flywheel to the hub. This combination gave a TOTAL weight of 13 pounds.
Were I to do this again I would go to a multiple disc clutch. Then you
would have the light weight AND the small diameter. To reduce the largest
diameter weight I even removed the ring gear teeth in specific spots as
I knew the engine always stopped in certain areas and I could probably
get away with it. Lots of work to not much benifit. We then
turned the engine to 7500 to with pretty good reliability. The rpm
range of the torsional vibration in the crank can be moved around but is
always there. The crank in the TR-6 has no overlap and thus is a whippy
devil. I made the weights as light as possible and this gave a problem
at about 4400 RPM again at 6100 RPM and then the last vibration was over
8000 and was not of importance. This third vibration by the way was so
severe it was off the page on the pen recorder. The biggest problem we
had was holding the engine revs at the proper amount on a yellow flag or
the pace lap to not be in the range of the vibration. I figured out
that light was good by the simple theory that if I tooled off the flywheel
to nothing, then what could fall off. NOTHING. Therefore light is
good. I would like to add that when we whipped the clutch flywheel problem
then the torsionals went to the other end of the crank and broke the timing
chain, we fixed that with a double row, then it actually sheared the camshaft
bolts to where we had to add another bigger bolt to keep it all intact.
Worth doing though, we WON. Made 252 bph at 7900 rpm in 1972.Boy this stuff
is old isn't it.
<P>David C. Wingett wrote:
<BLOCKQUOTE TYPE=CITE> <FONT COLOR="#000000"><FONT
SIZE=-1>Kas </FONT></FONT>
<BR><FONT COLOR="#000000"><FONT
SIZE=-1>
Thanks for your response. Yes, I have also had a fly wheel come lose but,
not disconnect ( last lap of the last race, fastest lap of the season).
Now, with the ATI balancer, and all the other balancing work done,
shouldn't that take care of any odd vibration...? The Tilton and
Quarter Master button clutches are very state of the art & balanced
to a Bone. The only problem I would see is finding a source for the
flex plate, using a stock ring gear (of course it would have to be CUSTOM
made, every thing else is) and calibrating a throw out bearing to match
the clutch. David W.</FONT></FONT>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT:
5px"><B><FONT FACE="Arial"><FONT SIZE=-1>-----Original
Message-----</FONT></FONT></B>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>From: </B>R. KASTNER <<A
HREF="mailto:kaskas@earthlink.net";>kaskas@earthlink.net</A>></FONT></FONT>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>To: </B>David C. Wingett <<A
HREF="mailto:elkhorn@megsinet.net";>elkhorn@megsinet.net</A>>;
<A HREF="mailto:fot@autox.team.net";>fot@autox.team.net</A> <<A
HREF="mailto:fot@autox.team.net";>fot@autox.team.net</A>></FONT></FONT>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>Date: </B>Thursday, March 11, 1999
11:25 AM</FONT></FONT>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>Subject: </B>Re:
clutch/flywheel</FONT></FONT>Having
had just a big bunch of history with the TR-6 enigne and flywheels and
clutchs flying off, making a installation with a light flywheel and
the lightest smallest cluch makes a significant difference in the durability
of the crankshaft and the available rpm. When making the flywheel (aluminum)
have the center hub as deep as possible with about a .002" interference
fit. This hub should then go onto the crank almost touching the seal. The
problem is that the flywheel actually wobbles as the vibration of the crnakshaft
is transfered to it and this movement is then trying to PRY the flywheel
off the crank. When you lighten, reduce the size of the clutch you reduce
this movment by about one half. I nmeasured all this on the dnyo
with a oscilloscope and potentiometers For the fitting you then heat
the flywheel and it will slide onto the crank end. I also drilled and taped
the end of the crank for FOUR more bolts. Use bolts that are HARD not just
strong. By hard I mean bolts that have a very limited stretch before
breaking. Bolts that are stong and stretch allow the flywhell to slide
around and wobble but the bolts don't break. Too bad, cause you are
still a DNF.. Machine bolts such as used for hold downs in shop machinery
such as a mill are hard and do not stretch. Kas Kastner
<P>David C. Wingett wrote:
<BLOCKQUOTE TYPE = CITE> <FONT COLOR="#000000"><FONT
SIZE=-1>
Since the question of clutch & fly wheels has arisen, I'm wondering
if anyone has tried putting together a small button clutch (Tilton or Quarter
Master) with a flex plate,on a TR-6 ? I can only imagine the rotating
mass coming down to near nothing.</FONT></FONT></BLOCKQUOTE>
</BLOCKQUOTE>
</BLOCKQUOTE>
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