Bad idea. You will have max advance all the time and it won't run better or cooler. If you want a higher idle rpm, adjust the throttle.
Jim

 

Yeah, if you do that, the reason for a vacuum advance in the first place will be lost.

 

the vacuum advance advances the timing when under vacuum, like when cruising down the road, then when you put your foot in it the vacuum will fall and the timing will retard, so you don't ping. hooking the vacuum advance to full vacuum at idle will work the same while cruising but at idle it will advance the timing and might make the engine idle cooler. thats why some of the older vech. you had to disconnect the vacuum advance to time them, they had full vacuum at idle. ported or non ported the vacuum advance will still work the same while cruising. i have a old ****** jeep with a 350 sbc in it and thats how its hooked up, works fine. as for turning up the idle, well i think ive figured that one out. i know the older car, with higher compression, you have to retard the timing to keep them from pinging, but by doing that you increase the combustion temps. advancing the timing, unless you get crazy, will lower the temps.

 

Guess what you win?

[IMG]local://upfiles/64738/8EF9A5B071A54FEEBBEABFB9240687D0.jpg[/IMG]

 

You're probably thinking, "Sure there is no manifold vacuum at WOT but aren't I supposed to use ported vacuum for the vacuum advance." Hold onto your hat, THEY ARE THE SAME THING! Except ported is shut off at idle. There are a lot of misconceptions when it comes to the ported vacuum source. After hearing 20 different theories I decided to hook up two vacuum gauges, one to manifold and one to ported, then drive my car and watch it. I found out they are the same, except the ported is shut off when the throttle is closed. Even then I had a hard time convincing guys so I hooked up a couple MAP sensors and a throttle position sensor to a data logger and recorded them while driving then dumped it into a spreadsheet and made a chart. As you can see, there is a direct relationship between throttle position and vacuum. When the throttle is closed vacuum is high, when the throttle is open vacuum is low, and ported vacuum is the same as manifold except when the throttle is closed. So which one do you want to hook it to? I prefer manifold vacuum. This pulls in more timing at idle which is good since there is virtually no load. Your motor will idle smoother and cooler with the extra timing.

 

When you're in the 'hole' that deep, stop digging.
Jim

 

well i installed a new vacuum advance yesterday and ran it to manifold vacuum. engine ran 170-180 all the way home, thats on a vdo gauge and the factory gauge never got above half. guess the combination of getting no advance out of the vacuum advance and a vacuum leak caused the problems. ill see how the rest of the week goes.

 

throwing my two cents out there because I had a similar experience, but the vehicle was a 318 mopar. Totally blew me away when I figured it out. Are you running lean? Yes, if you run lean, you actually run hotter. When everything else has been checked, and you are confident in your cooling system, this might be a realistic cause.

 

hey hotrod any way i could see some pic on how the vacuum advance hooks up to your manifold, i am havinga heating problem also and im just kinda looking for some idea's thanks

 

+ 1 on the timing, itcan cause more heat, Fuel/air too lean can cause more heat, bored cylinders can cause heat, lower octane fuels can cause heat. What is your base timing?