[TR] TR4 brake drum problem

[Randall]

>  The seller said they were off a 240z datsun.   Does
> anyone know how to mod a pair of these drums to fit the tr3?

I started on that project a long time ago, never did finish it.

First, you need a TR3 with 9" rear brakes (which as I recall did not come in
until sometime during TR3A production).  Fortunately, someone had robbed the
original 4.10 from my early 3A, and stuffed in an axle with 9" brakes.  The
9" are not hard to retrofit to earlier cars (as long as they don't have the
Mayflower axle), you just swap the backing plates, shoes, etc.

The stud holes have to be opened up; although the Datsun uses the same
diameter, the TR has shoulders on the studs that the drums must fit over.

Then in my case, basically the entire lip of the drum had to be milled away,
in order to clear the edge of the backing plate.

FWIW, I've also been told that the Datsun drums were not made using a true
Alfin process (which is a complicated method of bonding aluminum to steel)
but were simply cast aluminum around steel liners.  If that is true, they
will not cool as well as even ordinary cast iron drums (though of course
there will be some savings in unsprung weight).

Randall