[TR] tr3 distributor

Randall TR3driver at ca.rr.com
Sun Dec 11 19:32:03 MST 2011


> but I'm perfectly capable of
> doing it my self,

Finding parts can be a problem, though, and you should really run it on a
distributor machine to see if you got the advance curve right.

Yes, that's right.  It's puts a knee in the advance curve, for more rapid
advance up to a certain rpm, then slower advance from there until it hits
the stop.  For a 40480, the knee should be at 1500 engine rpm.

> i seem to recall being told that the centrifugal weights are 
> different for the 87mm pistons. y/n?

AFAIK, the factory never installed 87mm pistons.  But they did use several
slightly different advance curves at various times, as well as different for
83 vs 86, low compression vs high, and also TR4A vs TR4.  Just for grins I
plotted a few of them, you can see the results at 
http://fwd4.me/0iQ7

However, also AFAIK, the weights were always the same.  The changes in
advance curve (for a given model of distributor like your DM2) were
accomplished with changes only in the springs and advance stop.  The later
25D4 had completely different weights than the DM2, but again I believe they
were all the same within the model.

-- Randall  


More information about the Triumphs mailing list