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GM Alternator in a TR4 w/Dan Masters' Wiring....

To: triumphs@autox.team.net
Subject: GM Alternator in a TR4 w/Dan Masters' Wiring....
From: "Jeffrey J. Barteet" <barteet@nceas.ucsb.edu>
Date: Tue, 11 Jul 2000 11:18:37 -0700
Hi, Folks,

I replaced my Lucas generator and voltage regulator this weekend with a GM 
- AC Delco alternator with internal regulator.  I'll skip the originality 
debate and leave that for others.  I will say that other than clipping off 
the original slip terminals on the car and bending a replaceable bracket, 
no changes were made to the car.

Dan Masters has information on the conversion up at the VTR site, but when 
I wrote him a year or so ago for clarification on a point, he sent me some 
revised instructions.  The directions at the VTR site had an error in them 
at the time.  I don't know if that error has been corrected.  The 
instructions Dan sent me are attached at the bottom of this email.

My questions to Dan were about the mechanical aspects of the swap.  Namely, 
how did you adapt the car to a narrow belt, or how do you adapt the 
alternator to a wide belt and how does the alternator attach to the 
car?  He wasn't positive on either point, but mentioned that some people 
had no problems and some people had lots of problems.

I guess I was somewhere near the middle.   : ^ )

Here's what I did:

I decided to keep the wide belt and not mess with the water pump or crank 
pulley.  I looked briefly into some kits that change the early wide-pulleys 
to narrow ones, but they were too expensive for my taste.  ( more than $300 )

My car was already Negative Ground, and this is required by the 
conversion.  Fortunately the Negative ground conversion is insanely easy.
        a) Switch the terminals on the battery.
        b) Switch the terminals on the coil.
        c) Switch the terminals on the amp meter.


I bought a rebuilt GM alternator for $40 and paid the $10 core charge as 
well.  It was rebuilt by Total Quality Remanufacturing and is rated at 60 amps.

Step 1 ( Modify Pulley )

I removed the stock, cast-iron pulley from the Lucas generator and had it 
drilled out to the same size as the pulley that I removed from the GM 
alternator.  The cast iron pulley was the same 'stack height' as the GM 
pulley and replaced it perfectly.  I retained the fan that came with the GM 
alternator.

Step 2 ( Modify alternator )

I put the alternator in place and found that the mounting boss on the GM 
alternator was too thick, causing the pulley to be about 1/2" too far 
forward of the water pump and crank pulley.

Rather than modify my TR's mounting bracket, I cut a small piece of the GM 
alternators' boss off with a hacksaw.  A portion of the boss I removed was 
built up with some webbing on either side, and this is the portion I cut 
off.  ( Look at a GM alternator and you'll see what I mean. )

The alignment was perfect then, and I attached the alternator with a good 
3/8" bolt to the stock generator bracket which attaches to the block.

Step 3 ( Modify stock tension bracket )

The slotted tension bracket for the adjustment of belt tension didn't align 
with the GM alternator's other 'ear', so I simply increased the amount of 
offset it already had with the use of a vise and a large cresent wrench.

Step 4 ( New Belt )

The stock belt was too short now.  A trip to the Big Guns of car parts 
stores, NAPA, and I had a new 3/4" x 40" belt that fit perfectly.  The belt 
is made by Gates.

Step 5 ( Wiring )

I followed the instructions from Dan on using the stock wiring.  They were 
dead-on accurate for my early TR4 down to the colors on the wires.

Step 6  ( The Acid Test )

So I stand back, double-check my wiring, ponder for a moment who this Dan 
Masters guy is that I'm trusting with the wiring of my favorite toy, and 
fired it up.  The red light went out and the amp gauge showed the battery 
being replenished with juice.  The voltage at the battery was 14.25 volts 
at idle.

A weekend of enthusiastic driving has not found any problems with the 
conversion.

The conversion cost $50 for the alternator, $10 to have the pulley drilled 
out and $17 for the belt plus a few misc. electrical connectors.

All hail to Dan Masters!  King of TR wiring!

-jeffrey

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