Nufo

Ok so it's time to turn to the answer book.. That would be the brain trusts on this forum. I restored my '66 442 including rebuilding the original 400 with L69 Tri-carb. The car has been apart since 1984 (last time it ran). I get this thing running and it runs like crap. Check the usual things like dwell, timing and carb adjustments and settings. Notice timing with all in on the vacuum is about 51deg. WOW way too much. back the dwell to 27 and disconnect the vacuum advance and set the initial at 11 deg. Still runs like crap, better, but still crap. Idle is good, WOT good. Mid-range not so good. Even at cruise speed it bucks and feels like it's fighting itself to run. Mash the pedal and it kicks the end two carbs in and smooths out. Decided to pull the center carb and took it to a shop that has a test mule engine to bolt it up to. AFR hooked up and she's lean. Jumped up two sizes on the jets and bolted her back on to the 442 and it runs like a new car. Smooth, no stumble no hesitation no bogging and really a joy to drive. The disty is a rebuilt from the local Napa dealer. So there's some info for you as to background. Now my question is how do I deal with the excessive vacuum advance that the disty is putting in so that I can run the vacuum advance? Is there a particular vacuum advance unit that should be on the distributor as opposed to the one I have or can this one be re-worked to provide the correct amount of vacuum? It runs fine without any but I'm guessing I could pick up a little mileage by running one.

Thanks,
Nufo(Fred)

P.S. I'm guessing the jet size change over stock simply corrected for
the wonderful gasolene (if that's what we call this junk we have to
run in our cars these days). I'm guessing Ethanol has lots to do with
it.

oldcutlass

Set your dwell to 30, no more no less. Reset your timing to 36 all in at 3000 with vacuum disconnected and plugged. Snug the distributor down and then rev the engine while watching the timing to 4500 and make sure it does not advance anymore. Drive the car a bit and make sure it's not pinging. If it does, drop your timing 2 degrees until it goes away. With vacuum hooked up you should be at 50 or less. If it's higher leave it disconnected and get an adjustable vacuum canister.

Hope this helps.