Henry,
Speaking as a relative novice with high rpm TR engines, but being a
Mechanical Engineer with good materials experience, it depends on how the
flywheel was lightened and what forces are applied to it. The critical
items are the cross sectional area of the material remaining and the
resistance of the material to cracking, mostly based on the radii retained
in the corners and any imperfections in the flywheel.
The cross sectional area dictates how much material is left to carry the
load. More is better, but it adds weight which hinders our acceleration.
Based on conversations we've had about your machinist, I would assume that
he left nice, smoothly machined, wide radii in all the inside corners to
reduce the tendency for crack propagation to begin as well as insuring that
there were no obvious imperfections remaining. These are what I see as the
primary factors and the ones I considered when I had the flywheel in my
street/AutoX TR3 lightened (only to 21 pounds, still pretty heavy), but how
it all relates directly to RPM, may not be quantifiable. I'll leave that
to the high RPM guys. Knowing how thin and/or light you went on the
flywheel would be good information to ponder.
One thing (straying from the topic) which I think you and I discussed
previously, but brought up here for the FOT was that a doubler plate, a
second plate spaced away from the existing steel plates you have in your
car, will catch significantly more shrapnel(fragments) than will a single
plate the thickness of the two plates. Somewhat like the spaced armor
plate used by NATO and others, which I spent years designing tank
ammunition to defeat(great fun!). I wish I still had the software or calcs
to be able to determine the effectiveness of a double or triple walled
tranny tunnel and/or floor pan, which might be a simple, non-degrading way
to gain significant extra protection without impeding tranny removal or
gaining excessive weight. Just another avenue to consider.
Sorry I have no direct answers to your question,
Jack Brooks
1960 TR3A
1980 TR8
1974 Norton 850 Commando
Hillsdale, NJ
> -----Original Message-----
> From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net]On
> Behalf Of Henry Frye
> Sent: Thursday, September 28, 2000 10:21 AM
> To: fot@autox.team.net
> Subject: Scattershields?
>
>
> Greetings,
>
> All this talk on scattershields got me thinking. Always a
> dangerous thing...
>
> My car has canted vertical steel plate extending from the
> drivers floor to
> the bottom of the stock battery box. In addition, there is a 3/16"
> aluminium plate on the drivers floor that extends under the
> vertical plate.
> Looks simple, and somewhat effective at saving my legs. I was
> planning on
> replacing the floor plate this year with 1/4 steel. All this talk about
> scattershields and the relative affordability of Mordy's
> proposal got me to
> standing in line for one...
>
> As this thread has emerged, I have had a few thoughts.
>
> First, the idea of wrangling with an oil soaked kelvar encapsulated,
> fiberglass impregnated ballistic blanket makes the already
> painful job or
> removing and replacing an OD gearbox sound almost intolerable.
> I sort of
> like the idea of installing the blanket in the gearbox tunnel,
> and along
> with some steel in the drivers floorpan. To me, this sounds like a good
> solution.
>
> But, I have a question. I have heard the stories of exploding
> flywheels and
> clutches. I am missing one piece of data. What kind of RPM's
> does it take
> to detonate a flywheel and/or clutch? Am I in danger of loosing
> one running
> a stock crank with a lightened stock flywheel and a stock TR6 diaphragm
> pressure plate, the whole assembly balanced, turning a max of
> about 6000?
> OK, my telltale at the Glen did read 6500 after the feature... ;-)
>
> Or, is detonating a flywheel/clutch reserved to those of you
> running the
> Moldex cranks, aluminium flywheels and Tilton clutches and
> crank it up over
> 7000 regularly???
>
> As always, thanks for any input.
> Henry Frye - thefryes@iconn.net
> Finally added some race car stuff to the website.
> http://members.iconn.net/~thefryes/race/raceintro.html
>
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