Dyno Work

[L320-Dale]

That's great Randy!

[Randalla]

I re-gapped my plugs and tried to add 2 degrees of total timing, but the timing mark is jumping round so much I can't get an accurate reading. Will check slop in distributor shaft later, but any other thoughts. Seems strange as good as the car is running, but the rpms on my timing light are all over the place as well and I've ruled out the timing light. I tried both of mine and have the same issue.

[Vetteguy22]

Is it an electronic distributor? If so could be the electronics. If mechanical, I would definitely expect play in it.

[Randalla]

Mechanical distributor with Pertronix electronic ignition module.

[Vetteguy22]

I would start by grabbing the distributor cap and just try wiggling it. Make sure it is not loose in any way. If not, then remove the cap and check for play in the distributor shaft. If that’s tight, I’d be suspicious of the electronic module.
Does the timing move at all speeds or just as the rpms come up?

[Randalla]

Distributor shaft is tight with no wobble whatsoever. The crank pulley shows no sign of delaminating. Going to open up the distributor to make sure I don't have a spring off or something (which I doubt). At that point I'll begin checking wires for breaks or possibly a coil or Pertronix ignition issue.

[Vetteguy22]

I don’t think a spring would cause that. Broken wire would be consistent unless it’s a plug wire that is shorting.
Definitely would check those items first but would expect electronic issue.
Good luck. Can be a pain to trace down.

[Randalla]

Was attempting to set total timing at about 2500 rpm. I bumped rpm up to around 3,000 and things seemed to have settled down now. I now have total timing set at 36 degrees but have yet do a test drive, which I will do when things dry out down here. I'll let you know any seat of the pants difference I notice Rob.

[Vetteguy22]

Sounds good. Hope all goes well.

[Randalla]

I made a few additional adjustments I'm hoping may improve my initial numbers, besides adding 2 degrees of total advance. Opened the spark plug gap up to .035, replaced the ATF I was using in the carbs as damping fluid with 20 wt. fork oil and installed new 8 mm Taylor ignition wires. I also have two new needle profiles coming to address my air/fuel issue. Changes so far seem to have made some positive difference (seat of the pants) but until I install an AFM gauge or head back to the dyno I can't be sure.