XR700 + Clarks Pressure Retard...

All Models and Years
Post Reply
User avatar
Posts: 305
Joined: Wed Nov 02, 2016 5:54 pm
Location: Dahlonega, GA

XR700 + Clarks Pressure Retard...

Unread post by acarlson » Tue Jan 10, 2017 1:23 pm

Well, I finally got a chance to take my Corsa out for it's first test run with the XR700 and new Pressure Retard installed. Wow - what a difference. Before I could not get over 2K without the engine missing and running rough. Now it runs right up the RPM range without a hickup.

Notes on this install...

First the XR700. You have to be careful with the shutter install. If you slip it down as far as the instructions indicate, it will sit too low and possibly rub against the spring on the points plate. Of course I didn't discover this until I followed the instructions and discovered I had problems. I used a small pry bar to raise the shutter about 1/16" so it was now centered in the optical trigger and cleared the spring. Next running the wires out of the distributor cap was a small problem. You can use the existing wire exit notch but I found I still had to cut a small relief in the distributor cap. A dremmel with a cutoff blade worked well for this.

Then Clarks Pressure Retard: I thought this would be a plug-n-play install but that would have been too easy. With the Clarks Pressure Retard installed in the stock retard mounting holes, the retard arm pushed the timing rod right up against the side of the notch in the points plate.
file.jpg (130.71 KiB) Viewed 203 times
This left plenty of travel space for the vacuum advance but no travel space for the pressure retard. I fixed this problem by modifying the retard mounting bracket - essentially cutting a slot in the two holes for the mounting screws. This allowed me to shift the retard unit on the side of the dizzy so I could center the timing rod in the the middle of the notch in the points plate.

Once the idle timing was adjusted I was good-to-go. I've still got work to do but it's nice to make some progress once in a while.

Alec Carlson
1965 Regal Red Corsa 4 Speed Turbo Convertible

Post Reply

Return to “Ask your Mechanical Questions here”