I have a Clifford intake and 3 Weber 40DCOE carbs. I'd love to give them a try but it just occured to me that I won't have a vacuum advance. What, if anything, will I need to change to run without the vacuum advance?

Mike

My Weber page
MAndreas@aol.com

I'm assuming that you're referring to your ignition advance. The Mallory dual point distributor is mechanical advance only. Not the hottest ticket in town, and a bugger to setup. But they do work.

If you really do need vacuum, there are vacuum pumps to be had. I have one on my 6.9L Diesel for my power brakes. You could add one with a little work.

I'm betting Doc will have other options for you.

Gilly

tlg225ccr@aol.com

Mopar perf.has a meechanical advance dist too

Will


slantsix@netzero.net

I have a Mopar Performace "orange box" electronic ignition system now.

MAndreas@aol.com

Hey Mike,

Why can't you run vacuum advance? Isn't there a vacuum port on the manifold anywhere? You could just drill and tap an NPT port on one of the runners while it's still out of the car. As long as you don't have any leaks (e.g., blown Vac pod), then you should be fine.

Lou

I have put a vacuum gauge on the manifold and the vacuum port on the carb just to see what the difference was and they don't behave the same. I can't remember exactly what they do. I'll try it again this weekend. I'm up to my eyeballs this week at work. (End of the season). The vacuum port on the carb gets its signal from right by the butterfly I think.

Mike

MAndreas@aol.com

Mike,
Why are you concerned about vacuum advance? Vacuum advance is used on street cars as an economy enhancing feature, it only comes into play under partial throttle cruising condtions.

I would go ahead and try your webbers out. Once you have it sorted out you could plum in a vacuum advance if you want.

You also mention using the "orange box" ignition. This box is only different from the standard electronic ignition box in that it is faster allowing the igintion to operate at higher rpms.


Hot-Rod 6
dave.clement@motorola.com

Vacuum advance is not supposed to be active at idle. If it was plumbed into the intake you would have a high vacuum signal and the advance would activate. The carb port is just above the butterfly so there is no signal at idle.
: Mike


Hot-Rod 6
dave.clement@motorola.com

I can't help with the timing, but for tuning go to <A HREF="http://www.inglese.com/tech.htm">http:/ ... ech.htm</A>

snarl@net-change.com

mike-
one of the many the beautiful characteristics of the weber setup is that the carbs are not dependent on a large source of vacuum (plenum) to work properly with a race cam. most race cars do not use vacuum advance anyway. you won't be able to plumb a port anywhere with this setup as vacuum advance works off "ported vacuum" to keep the vacuum advance from working at idle. without a good mechanical advance distributor you can just leave you vacuum distributor disconnected and it will work just fine. you could also take it apart and "lock" the vacuum advance plate with a sheetmetal screw or something. just make sure you have enough total advance as well as proper base timing and you should have no worries.

ludite123@cs.com