[TR] What time is your distributor?

Randall tr3driver at ca.rr.com
Wed Dec 5 15:51:29 MST 2007


>       Please don't answer these questions if your car is not 
> properly timed...

Paul, I can't answer your questions directly, but I do want to point out
some problems with them.  The first is that you have not specified what you
mean in the above statement.  "properly timed" would normally mean only that
the spark happens in the correct cylinder at the correct time ... which
might mean anything as far as which wire appears in which location.

IOW, the orientation of both wires and distributor body is influenced by how
the distributor drive gear is engaged with the camshaft.  No matter how that
is done, "correct timing" can be obtained by adjusting which wires are
connected where and/or the position of the distributor body.  My Dad's TR3A
has the wires exactly opposite of where mine are, yet it is "properly
timed".

> (1)   Do you have 2138cc's as opposed to the earlier 1991cc's?

Do you mean originally, or whether the 86mm liners have been retrofitted to
an earlier engine ?  In my case, neither displacement is correct, since I
have the 87mm liners (fitted to a cylinder block that was originally
1991cc).  However, it doesn't really matter, since changing the liner size
does not affect how the ignition is timed (or how the distributor/wires are
oriented).

> (2)   Do you know if it is a DM2 distributor?

Again, has no bearing on wires/orientation.  The later 25D4 is fully
interchangeable, without altering the relationship of wires/dizzy.  My
engine has been retrofitted with the 25D4.

> If one stands on the left side of the car, with the bonnet 
> open, and stands
> directly over the distributor,
> (3)   where is the the cap's no.# 1 wire? (What position on a 
> clock dial?)

Assuming you mean with the engine at 12:00, my #1 wire is at 9:00.

> (4)   What direction does the vacuum advance point?

9:00

> (5)   What position is the little wire enter the dist. that 
> comes from the
> coil and goes to the points at?

About 12:00

> (6)   With the cap still on, and hoping that it is a British 
> Style cap (2
> lower, 2 upper wire cap), which direction does the cap point 
> (because of cap's
> top coil wire)?

6:00

IOW, my installation looks almost exactly like the illustration in Practical
Hints (within a few degrees anyway).

As Peter notes, there are different caps that will fit both the DM2 and the
25D4.  In addition to the one with the terminal turned 90 degrees from the
Triumph cap; there is also a cap with the terminals pointing straight up;
and I believe yet another one with the terminals all on the side of the cap
in a row (rather than half on the side and half on top like the TR cap).
All were originally made by Lucas, and just used in different applications.

Randall


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