Gosh - I didn't know that asking how to limit the maximum amount of vacuum advance could generate such "animated" responses!! Quite a lot of passion around the topic of timing!! Heck, ask a simple question and we got guys picking at each other and AJ wants to "say bad things to you and about you" (talking about me)!! I'll chalk that up to this internet thing as someday I think it would be great to meet up with a bunch of you. After all, we all share a common love for these old cars!!
The "How to" post really helped - I like the set screw on the side idea but until I get time to pull the dist and take it apart and look at it, I'm not sure which method I'll use to limit the advance.
As for the timing, I'm ok with the mechanical advance part. The 35 total is in line with many published articles about what these engines want (this is a 10.5 CR Eddy head engine). If I recall when I set the timing, that 35 degrees is all in by about 2800-3000 rpm. It's close enough for my little motor anyway. This dist has 22* total mechanical advance so that means the idle gets about 13-ish. I haven't measured the idle vacuum on my car yet but I can tell you it certainly ain't much!! So ported or MV would not make much diff at all.
For part throttle street operation, a bit more advance is all I'm after. Without having it on a dyno to optimize every speed/load, "a little bit more" will be just fine. I'll limit the max vac advance to about 20* so that will add to whatever the mechanical advance is at the rpm the engine is spinning. That will most definitely help with fuel consumption. Is it ideal or perfect? Nope - that's what electronic systems are for and this is just a simple dist. I'm just trying to make it a tad better than it is today without any VA. It's not even so much about burning less fuel; it's as much about keeping the plugs cleaner driving on the street. (Although this thing DOES suck some fuel puttering around. Not sure if it's the engine or my right foot!)
Thx again!! I truly enjoy this FABO forum and all the info shared on it!!
