I have a 460 that I would like to set the timing properly rather than just twisting the dizzy until it "sounds" right. Can someone break it down for a rookie, please? Advise what tools I'll need and where to begin. Thank you in advance.

 

Ignition timing is actually somewhat complicated, the part that most people are familiar with - turning the distributor body - is just a small part of it.

That determines the base timing, sometimes called initial timing. Mechanical distributors use a system of centrifugal weights and springs that vary the time the plugs fire based on engine RPM. As engine speeds increase the fire needs to be lit earlier, so the flame front occurs at the optimum point in the piston cycle. Too late and the piston is already moving down and power and efficiency is wasted, otoh too early and engine "knock" or pre-detonation will occur causing engine damage. Most V8 operate around 34° or 36°, somewhere in there, at the far end at high RPM. Under steady low load level ground cruise conditions the vacuum advance will pull in quite a bit more, somewhere around 50° BTDC

Anyway you'll need a timing light of course, a basic unit is fine. Flourescent timing tape is available that make the marks on the harmonic balancer a whole lot easier to read. A tach.

Every engine is a little bit different, elevation you live at, compression ratio, camshaft, and fuel quality among other things like gearing and weight, play a role into the optimum timing or curve. The idea is that the maximum possible ignition timing advance (short of dangerous ping or detonation) is operating at all times under all conditions. Consequently the distributor timing curve is really what you're interested in. This is the amount of ignition timing BTDC, expressed in degrees, at different RPMs all the way out to 4000 RPM and beyond.

Vacuum advance is a wholly separate and distinct ignition advance (and retard) system that is based on engine load, not engine RPM. The two systems complement each other. Basically one is increasing ignition timing anytime the other is decreasing and vice versa. It's a PITA setting things up but it's worth doing. Plenty of folks spend big bucks bolting on high dollar goodies and then leave a lot of power and efficiency on the table. Take the time and get things dialed in and you'll thank yourself everytime you drive it.

 

 

I probably wouldn't be the guy to ask on that, my slick is ancient tech. I just use a 2 D cell battery powered unit (just one wire) from Flaming River, about as simple a timing light as it gets.

A lot of guys recommend what's known as a "dial back" timing light. But I've read these sometimes give wonky or erratic results depending on the particular type of ignition system. They cost a fair bit more too than a bssic model. For your application I'm not really sure. Would hate to recommend something that doesn't work.