Timing questions

[Ghoste]

First off, what was that method you used to set timing by ear again Neil?   I seem to have lost that.   Secondly, just how far out can an older damper get?   I'm, trying to set the timing on my car and it seems like the damper is a loooong way from where I thought it should be.

[Ghoste]

I think I've already figured out part of my problem.  Prior to timing the car, the distributor was in there pretty tight.  When I was loosening it, I pulled it out of it's bore about 1/4 inch, I'm betting I'm a tooth out now.

[Chryco Psycho]

maybe , I bring the engine up to 3000 approx & advance the timing until the RPM just stops increasing back ti off agin until you can just see or hear a drop i nRPM & tighten it up

[Ghoste]

This is with an MP electronic wwith vacuum advance on it btw.  Do you do anything with the vacuum advance ones after? (I know to unhook it for initial and I know you prefer to run without)

[Chryco Psycho]

the easiest way to shorten the timing curve is to leave the vacuum advance disconnected, most engine run far better with a shorter curve

[Ghoste]

So, if they run better without the vacuum, then it's pointless to run the vacuum in the interest of fuel economy?  What, when, or how would it be beneficial to use vacuum?

[Chryco Psycho]

Does EGR help a car run better ?
virtually any car I tune has both better power & milage without the vacuum advance

[Ghoste]

But EGR dilutes the fuel charge.  That one is obvious to me.  How does vacuum advance help fuel economy (at least in oem theory) because now you're telling me that I'll see better mileage without it.

[General Ryan]

Sorry to interupt, but I was wondering, is this something I should/could also be doing to improve mine as well (disconnect the advance unit and retime the motor)?
Or is this more of a performance/raceier setup rather than all street?

[Ghoste]

Having the timing properly set should be part of any tuneup or maybe even a routine check.  That you probably already know.  As to the vacuum advance, well CP, should we disconnecting these things even for regular cruisers?

[firefighter3931]

I never run vacuum advance. On that combo i'd be dialing in 18* of base timing and 36-38 total all in in by 2500-2800 rpm. You might have to weld up the plates to limit the mechanical advance and swap springs in to tailor the curve.

Here's some good reading on carb tuning and dialing in the ignition curve :

http://1970chargerregistry.com/70messageboard/viewtopic.php?t=1207

Ron

[Ghoste]

Thanks Ron.  Everybody needs to go read that thread if they are stuck with tuning issues.