Could someone post more detail of "timing with a vaccum guage"?

[reamer]

From what I read in a recient post "18 degrees," Hook up a vaccum guage and rotate the dist, till max vaccum ia achieved. Then lock down the distributor? or rotate a little more? Colckwise or counter?
Thanks
Reamer

 

[broncnaz]

I usually dont get the best results by getting max vacuum with ignition timing. It usually causes my setup to detonate at speed.But I do have a quicker than stock advnace curve so that may be why. For me the best way without a timing light is to loosen the dist start the engine then rev it to about 3000 RPM's and hold it there then turn the dist until you find the smoothest running spot. then lock the dist down.
Next you can hook up your vacuum guage and adjust the idle mixture screws until you reach the highest steady vacuum.

 

[gearida]

I don't understand you have a vacuum gauge and not a timing light? That purchase was backward, if you ask me. Vacuum can be different depending on camshafts and quality of the internal componets. Plus if you have points then you should check dwell as well. You really need timing light to do it correctly. As said the vacuum gauge is to adjust idle or check the condition of valves and rings. Again if you have a camshaft that makes power above 3,500 rpms you may not get 18 inches at idle.

 

[Scrapper_MV]

I use a vacuum gauge to readjust timing and carburetion when I go up in the mountains. I adjust the timing until I get max vacuum at idle and then retard the timing just a little. Works good for me from the beach to the mountains and back.

A vacuum gauge is an excellent tuning device that can tell you a lot about an engine. No garage, or glove box should be with out one. The Bronco I'm currently building will have an Autometer vacuum gauge installed in the dash.

Here's some info about using a vacuum gauge.

http://www.secondchancegarage.com/public/186.cfm