i know that both the bosh and motorcraft POINTS dissy's were intended to be run off the manifold vacuum...however unsure of the electronic dizzy's...4vxc said:straight gas, bosch electronic dizzy
if it hasn't been giving you any problems,and hasn't been pinging or detonating,i wouldn't worry about it..4vxc said:10 years fresh, built for gas 351 2v, impco 425, small cam for towing, been on gas from the start. I have the vac advance hooked up to manifold vac but am not sure if thats correct
73falcongt said:Manifold Vacuum actually drops as throttle is opened. As far as I knew the hose connecting to the vac. advance nipple of the dizzy should increase with vacuum (that is suck more) as the throttle is opened. I don't think thats what you get with manifold vacuum it's the opposite. Someone correct me please if I'm wrong, I'm curious myself.
73falcongt said:Mmmmm, I thought that timing was advanced the more load the engine was under. Now I've found out the more load the engine is under, the less timing it receives. Why is this? I originally thought that the point of the vacuum advance was to add more timing as the throttle was OPENED, because more mixture requires longer to burn, why is it the opposite way?
Also, I thought that was one reason why old dizzy style cars would tend to ping under extreme load, like uphill or full throttle in high gear, because the vacuum advance mechanism would weaken and allow too much timing advance at full throttle under load. Mmmmmmmm, shows what I know.
My Suzuki I had, the dizzy vac. advance hose I'm pretty sure increased in vacuum, that is it would suck more the more load the engine was under, and the more vacuum the earlier the timing would be. So that hose would suck the most when opening the throttle.