Timing Curve on 360 in an RV

Mopar73340 said
There is lots of good advice here, the only problem is most of it with the exception of the total and initial timing only apply if you’re running the factory distributor and vacuum can.

First off make sure you set the distributor per Edelbrocks instructions at 12* By locking the timing with the tablet And verify by timing light assuming you’re balancer is good. Then set your initial 16-20* and total in timing as suggested earlier to all in 32ish * at say 3600.
Adding vacuum advance with the Pro Flo 4 WILL affect idle timing slightly.

The most important takeaway here is to verify the 12* with the timing locked out because if this is off the computer has no was to know where the timing is And all other timing parameters will be off. The advice you received on the tech forum over there for 22* at 2200 was BS.

Report back with results but from my playing with this system it does not like anything more than 34-36* total without the backfire issues.

I've checked and locked in the base timing at 12 degrees via the "set base timing" workflow through the app. Timing light on wire #1 shows it right at 12, though the markings are a little hard to see. Worse case scenario I might be a degree or two off in one direction or the other, but that'd have little impact overall as I'm tuning.

When I set up an initial tune at 16 initial, 30 all-in at 3000 rpms with 5 degrees of vaccum advance, I was getting consistent backfiring anytime I was around 27 degrees of advance or higher, and acceleration was very rough. Anytime the engine was under load, things were not running smoothly. I could even get it to consistently backfire just by revving the engine up to 3000 rpms in park. This is the scenario that started my journey to the odd settings I currently have - an effort to tune out the backfiring and find a tune where I would get reliable, smooth accelerations.

That current tune is 16 initial, 21 total all-in at 2200 rpms. But that seems super-off from where I should be.