I've got a '65 Ginetta G4 that I'm taking vintage racing when I finish
restoring it. It's got a Spridget live rear axle with 7" drum brakes.
Or at least they normally do (that is, the ones that didn't have the
Ford 10 rear axle).
Mine's got the Spridget axle, brake backing plates, and brake drum.
All the internal brake bits are Spitfire. The top of the backing
plate had a big rectangle cut out of it, and the corresponding piece
of a Spitfire plate welded in. A couple of holes were drilled for the
shoe retainers, and all the Spitfire internals were substituted.
Now if *I* had gone to all this trouble, I would have at least
upgraded to 8" or 9" drums, but who am I to say. I can only
conjecture as to why someone else did it:
- the front suspension and brakes are Spitfire, and they wanted
everything consistent?
- the Spit wheel cylinder has one less seal to leak?
- something else is better about the Spit internals?
- they had Spit stuff on hand, and the brakes that came with the axle
were dead?
My first inclination might be to put everything back to stock (even
though that's a pretty meaningless term for a Ginetta). Except that
before I noticed this I had the shoes relined with Ferodo Green.
Can anyone postulate on whether or not I might have trouble with this
system? The welds look to be quite solid (although I didn't X-ray or
Magnaflux them).
I also noticed that the SCCA period homologation specs allowed
upgrading the rear drums to aluminum. Since the axle's pretty heavy
to start with, and it's all unsprung weight, this seemed like an idea
I might want to pursue. Do aluminum brake drums have iron inserts for
the friction bearing surface, or do the shoes ride directly on
aluminum? If so, do they use a different pad? (It seems like
aluminum would gall up most any friction surface.) Does anyone know
where aluminum Sprite drums can be found? Or would this upgrade most
likely include swapping out all the brake hardware and putting on some
Alfa parts? Lastly, how much weight are the aluminum ones going to
save me (or do they just dissapate heat better?), and how much is it
going to help the handling of the car?
-- Jeff.
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