[Chris_oz]

Now that the “Chevy Shed”, as it has become known, is finished, I got some time to work on the Chevy.

Oil and filter change, check / set timing, check operation of vacuum advance, check operation of mechanical advance.
Set idle mixture and give it a general once over.

It has a Pertronix Ignitor fitted.
I find it unusual that the hall affect trigger mounts to the rotor button, so it advances with the rotor button as mechanical advance comes in. I would have thought it would in effect double the advance, but it doesn’t seem to.

I found the earth strap from ignition base to distributor body was loose, wire was still making contact, but just flopping about, it was mounted to the vacuum advance mount screw, so it too was just floating.

The mechanical advance weight springs are very worn and loose, I can remove the springs by hand with ease, I ran a look-out check, the worn springs and pivots are giving me +8 degree of mechanical advance even at idle (650 rpm)
I added some stiff o-rings to the shafts along with the spring and even removed one of the weights, it slowed the advance rate but was still adding 6 degree mechanical advance at idle.

With timing set at 12 BTDC at 650 rpm (4 degree base and 8 degree from work mech advance) with vacuum off and plugged, all in by 2100-2200 rpm and only 28 degree advance.

It has a new B1 (Echlin VC-680) vacuum canister fitted, it is functioning as it should, started to add advance at 8 inHg, all in by 18 inHg and added a further 16 degree, but the timing was floating a few degree with the mechanical advance still working, I was doing the check just over idle using a vacuum pump.

I think it might be time for a rebuild or new distributor, everything is worn in there.

I have been looking at alternatives and like the idea of the All-in-one HEI with coil in cap, but they are ugly, and I do like the stock look.
I have bought a set of weights and springs with advance limit bush to see if I can get this back to a working condition, if not I will decide which way to go.

Tonight I will do a wet and dry compression test, she blows a little blue smoke on start up when cold and I would like to know if its valve guides / seal or rings.
The oil was WAY over full, almost 1” over the high mark on the stick, I know that doesn’t help with smoke (or power), so I will see how it is tonight when cold with fresh oil at the correct level.