halifaxhops submitted a new Article: Everything you wanted to know about ignition advance Read more about this article here...
Maybe I missed something basic here........."where did" you get this? I did not see credit to the author, or did I miss that? "For peak engine performance, driveability, idle cooling and efficiency in a street-driven car, you need vacuum advance, connected to full manifold vacuum. Absolutely. Positively." I'll tell ya who this sounds like.............FBO!!!
I used it to set up my Mallory disty. So today I will see how well it works or if I need more adjustment. I am using a mechanical disty.
This is a nice article and it really explains a lot of questions that I asked within the forums. The one thing that really sticks out, is the recommendation to run full port vacuum at idle. How many slant 6 owners are using full port vacuum at idle?
I think I found the right information in this link which conflicts with the author. The author states that there should be full vacuum to the distributor at idle. Rough idle when warm? - Slant Six Forum
The full vacuum thing is quite a controversy. Folks have "made it work" either way. The whole system takes on completely different strategy one way or the other
Couldn't get my big cam 318 to idle without manifold vacuum. On ported it wanted to over heat at idle and shake the livin crap out of the whole car. had to run it at 1100 rpm to idle in gear at a light. Put an adjustable can and a travel stop on the rod. The can started pulling in at 6" vac and was all in at 12". The rod stop limited idle vac advance to 24*. Ran great after that and idled at 800 rpm. still shook a bit more than a bit but I could idle in gear without stalling, over heating or chirping the tires when I put it in gear.
you can put together ten engine specialists and you are going to have probably ten different comments. knowing how to truly understand the true operation of an Otto cicle engine is not easy. the text simply wants to show the functioning of each element of the distributor. When I started my job, the spark plug was my only indicator of the correct setting (1984). and in 2020 I use: a "Horiba" engine test bench, individual exhaust temperature sensors, lambdas sensor minimum two, see even one for each cylinder, MAP sensor, air temperature, rpm, water temperature at several points engine and cylinder head, and much more .... And finally I realize that I know nothing and that every day, I have more questions to ask than answers. the history of humanity is summarized = attempt and error
This is from Don Gould of 4Secondsflat.com. It explains ported vs manifold vacuum. Ported vacuum source, Constant manifold vacuum source explained, the difference between ported and manifold vacuum.