Initial Timming?

[bvt69dart]

My question is about setting your timming with a vacuum gauge. I've heard that you adjust to the highest vacuum at idle, and then retard 1" of highest reading. Is this accurate, & should the vacuum advance be active or plugged during this procedure? (my advance is connected to a timmed port vacuum source.) 318 w/ edelbrock 4bbl., & mopar performance mid-range camshaft.
Thanks.

 

[fishy68]

If the advance is correctly connected to a timed port it shouldn't matter but to be safe you should unplug it. I adjust it for max vacuum that'll allow it to start good. I have ran into a couple cases where the cam was pretty big so max vacuum wasn't until 30 degrees and the starter kicked back so I had to back it off a little so it'd start ok.

You may know this but in case you don't make sure and limit how much total timing you have after you figure out what idle timing you need. If you just adjust the timing for max vac at idle without modifying the amount of centrifugal advance you may end up with 45-50 degrees total timing which could destroy your engine.

 

[bvt69dart]

Thanks, I just found the specs on the Mopar electronic ignition kit I installed that stated that 50degrees @ 2600 RPM max advance for my 318. I set it to that, adjusted the idle & road tested. What a difference! No ping and lot's of low end!

 

[fishy68]

Wow 50 degrees! I'm surprised it doesn't ping. Must be a pretty low compression engine. Just watch for pinging and if it's ok your good to go. Initial timing is where the low end power is. When you get that set up right it does make a big diff.