[TR] TR4 Distributors

terryrs at comcast.net terryrs at comcast.net
Sun Dec 9 07:42:02 MST 2007


Hi, Paul.  You are probably addressing this to me, since I posted some questions on the topic a few months back. 

I did have a DM2 distributor, and I wanted to move into a Pertronix electronic ignition.  What I found was, there is a Pertronix unit for the DM2, however it comes only in positive ground.  I had converted to negative ground.

I did source both--a 25D distributor and a negative ground Pertronix unit for it--from Fred Thomas.  It dropped right in with minimimal effort, fits snug, and runs the car at peak performance, so the TR3A is finally free of the not-so-subtle degradations in power that I was experiencing as the poor quality plastic arm on the points rapidly wore down.  I didn't keep the model number on the Pertronix unit, though.  

Have fun!

Terry, (TS 58667)
New Hampshire

-------------- Original message -------------- 
From: "Paul Dorsey" <dorpaul at negia.net> 

> Hi, 
> It's been a long time since you posted this: 
> 
> Mechanically, there are differences between the DM2 and 25D4 units, This 
> means that the Pertronix magnet sleeve that is correct (size/orientation) 
> for one is not right for the other. Even then there was variability in 
> production tolerances. The Pertronics for my 25D4 did NOT have a snug fit 
> on the shaft and wiggled probably 3 degrees in either direction. Tech 
> Service told me how to improve that, but it was definitely a Rube Goldberg 
> fix. 
> 
> But I was wondering, did you ever get a Pertronix (or other brand) to fit in 
> your 25D4 distributor? 
> I am thinking about it. 
> 
> Thanks, 
> Paul Dorsey 


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