Lawrie,
I can offer a few partial answers, although I don't actually use Kevlar
linings myself. Kevlar is a common lining material used by racers. It has
a reputation for being drum-friendly, heat & fade resistant, and working
pretty well even when cold. At least, from a racer's perspective. Any of
the Kevlar brake suppliers could re-line your shoes (it is not a matter of
finding Kevlar brakes to fit your MMM car, you just send them the shoes to
re-line).
Hopefully one of the MMM owners will have some experience that is more
specific to a street-driven MMM car.
Not sure which brake "problem" the MMM guys are trying to solve. If it is
really brake FADE, that means you need to carry more heat away from the
brakes -- i.e. Alfin, larger drums, cooling holes, etc (or use a lining
material that maintains its properties at higher temps). If, on the other
hand, it is NOT fade but just raw braking power (car does not stop fast
enough, even when brakes are cool) then you need to generate more braking
torque -- i.e. larger drums, or lining material with higher coefficient of
friction. In my experience, many people aren't really clear about which
type of braking problem they are trying to solve, and they sometimes pursue
a solution to the wrong problem.
Not sure if Kevlar would have a greater CoF than asbestos or metallic
linings, a good question to ask the suppliers.
Regards,
Mark Palmer
>From: Lawrie Alexander <britcars@juno.com>
>Reply-To: Lawrie Alexander <britcars@juno.com>
>To: mgtom@bright.net
>CC: mg-mmm@autox.team.net
>Subject: Re:
>Date: Tue, 24 Oct 2000 08:41:46 -0700
>
>Tom,
>
>I'm familiar with Kevlar as a product but haven't heard of it for brake
>linings so the following questions seem warranted.........
>
>1. What are the benefits of Kevlar over conventional linings?
>2. Do Kevlar linings have to be really hot to provide maximum braking
>efficiency?
>3. Assuming "yes" to (2), can a MMM car, (even a blown one) generate
>enough speed and braking effort under normal driving conditions to get
>Kevlar linings to work well?
>4. Are Kevlar linings suitable for day-to-day driving of a MMM car?
>5. Are Kevlar linings readily available in sizes to suit MMM cars? If so,
>from whom?
>6. One would presume Kevlar linings are more expensive than conventional
>linings. For normal use, would there be benefits that would justify the
>additional expense?
>
>Thanks in advance for your answers,
>
>Lawrie
>(Supercharged PA that, hopefully, will need more braking than stock
>cables ever gave!)
>
>On 24 Oct 2000 09:07:39 -0500 mgtom@bright.net writes:
> > Some say 12 inch brakes from a P type will transform the braking
> > others say that
> > both 12 and 8 inch are not really much different and I
> > should just accept the standards of 70 years ago. Mike
> > Hawke says that the 12 inch conversion will add a lot of
> > weight to the car.
> > Advice would be appreciated from anyone who has experience
> > of this.
> >
> > From my experience experience with J's, P's, and fast racing cars
> > with 12" brakes, I think the advantage 12" brakes have over 8" FAR
> > outweighs any weight difference. Also, I would recommend kevlar
> > linings bonded on the 12" shoes and have them dialed in to your drum
> > size on a lathe. Now your braking will be up to the task of
> > clamping down the extra massive horsepower from the blower! tom
> >
> >
> > Download NeoPlanet at http://www.neoplanet.com
> >
> > British Cars Web: http://www.team.net/sol
> > MMM list subscription info: http://www.team.net/cgi-bin/majorcool
>
>________________________________________________________________
>British Cars Web: http://www.team.net/sol
>MMM list subscription info: http://www.team.net/cgi-bin/majorcool
_________________________________________________________________________
British Cars Web: http://www.team.net/sol
MMM list subscription info: http://www.team.net/cgi-bin/majorcool
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