Distributor modification,

By Bob Legere.

As I need to order some components to create my EFI compatible fuel tank,
I decided to concentrate on the distributor for the engine instead today.
After the tear-down, all the parts were cleaned in preparation for modification to the advance mechanism.
Here they are, layed out.

One of the more critical aspects after removing the vacuum advance,
Is making sure the upper breaker plate doesn't float around and alter the timing randomly.
To ensure full accuracy, it should be centered in the 'neutral' position rather than advanced or retarded, at least more or less....
Once the breaker plate was centered, I riveted the two plates together to keep them from moving.

This is the position of a fully extended advance weight.
For this year distributor, mechanical advance is listed as 28-32 degrees.
My intention is to set the baseline timing at 10 degrees, and let it advance to a maximum of 25 degrees.
So I need 15 degrees of maximum advance for this to work, which is roughly half of what the stock advance happens to be.

Here's the same advance weight in its' fully retracted position.
Note the gap between the two black marks....it's about .400" wide.
I'm targeting reducing this gap to .200" to cut my advance in half.

This is my solution for reducing the amount of advance this distributors sees.
I drilled and tapped the advance weight stops, and used a couple of 4mm allen screws as limiters.
The screws can't be too long or they will hit the inside of the distributor housing BTW....
I used high strength Loctite to secure the set screws.
Both sides are needed, and they must be adjusted equally.

I couldn't finish the distributor today,
I'm missing a couple of pieces like one advance spring and a rolled pin for securing the drive gear.
I also have to make an aluminum sheetmetal cover for where the vacuum advance used to be.
But this is what the polished housing looks like with the Compufire ignition pickup in place.