Dear all with interest in alloy brake drums with cast liners.
Having made a number of these replacement parts when I owned Halibrand
Engineering, Most are cast sleeves with lugs protruding on the periphery of
the sleeve, tapered in both directions to prevent the sleeve walking out.
the sleeves are placed in the mold after the pattern in removed. (sand Cast
and perm Mold type casting). The moltem magnesium or aluminum is extremely
agressive in fixing itself to the cast iron liner. Ted Halibrand had me
plate the external part of the sleeve with cadmium to make it "stick"
better. We never had a failure with the sleeve coming loose. Some early
Ferrari's have a sleeve that is made separately annd has many rivet to hold
it in place. Remember if you try to shrink fit the sleeve that with heat
the aluminum expands away from the cast sleeve and you lose the
interference fit. Not wise proceedure.
Sorry to be a wet blanket but please be very carefull with home built
suggestions here.
Wayne Mitchell, Chief Tech Inspector VARA
Manufacturing engineer- Mechanical and certified car nut.
-----Original Message-----
From: Simon Favre <simon@mondes.com>
To: Brian Evans <brian@uunet.ca>
Cc: Vintage Race <vintage-race@autox.team.net>
Date: Friday, January 21, 2000 1:38 PM
Subject: Re: Speaking of drum brakes...
>Brian,
>
>Machining away on a drum of the correct ID probably would be the way
>this could be done. The pegs I referred to aren't radial. They stick
>out the face of the drum against the wheel, not the circmference of
>the drum. I don't think they were cast in place because of the pegs.
>Certainly on the Fiat ones I would like to renew, the intricate
>casting of the ventilation holes and subsequent machining operations
>would seem to indicate the drum liner was added afterwards.
>
>The Alfa drums defintely have these pegs, but I'm not sure about the
>Fiat ones. Fiat may well have done it as you suggest, with splines
>on the liner and outer part of the drum.
>
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