[HotRod63]

what does total timing mean? i was told to set my timing at 10 degrees advanced and 35 degrees total timing is good i know about the 10 advanced but the total im not sure of.

[Infomaniac]

Total timing is the total amount of timing the engine sees from the distributor. It happens at a much higher RPM than idle after the centrifugal advance is all the way in.

Initial timing plus mechanical advance = total timing.

To measure it you must have timing tape on the balancer or a timing light with a retard functon.

[nitrous_69stang]

So what is timing? In a nutshell, timing or 'ignition timing' relates to when the sparkplug is fired in relation to piston position. At idle, when engine speeds are the lowest, the plug fires just before the piston reaches the top of its stroke. As engine speeds increase, the time between piston strokes is less, and therefore the plug must fire sooner. In all cases the plug is fired in advance of the piston reaching top dead center. There is a small window of time in which the combustion need to take place in order to produce peak power. Too late and power is lost that is what You are experiencing , too soon and detonation occurs, which can lead to melted pistons. Depends on your car compression etc. but i would go with 35 total.


Initial: This is the most common adjustment that people associate with timing. At idle, with the vacuum advance hose disconnected and plugged, this is the timing that you would see if you flashed timing light on the timing marks. On typical stock engines you'd see as low as 0 to as high as 15 degrees.

Mechanical/Centrifugal: Most V8 distributors contain an internal advance mechanism consisting of two each of weights, springs, and slotted 'reluctor' arms. There is also a stop tab for the arms. . As the distributor shaft spins with increasing rpms, the centrifugal force acts on the weights, which begin to force outwards against the springs. This movement rotates the shaft and thus advances the timing. The slotted arm controls how much the weights can move the assembly, and the springs control how fast the assembly reaches that limit.

Total Advance: Say for example initial was found to be 6 degrees, Total timing, theoretically, is then the initial + mechanical. If we shined a timing light on the marks (with vacuum hose disconnected and plugged), at idle we'd see 6 degrees, then as we increased the engine speed, we'd see more and more advance, until at some point the total centrifugal advance would be reached, When exactly the total advance occurs is of great importance when it comes to performance.

Let me Know if you have any more questions.

[rooster]

IN MY OPIOIN I WOULD NOT RUN A VAC ADVANCE DIST FOR PERFORMANCE. SMALL HORSE STREET ENGINES MAYBE BUT FOR PRO-STREET PERFORMANCE A DIALED IN MECHANICAL IS BEST.

[bullheimer]

here's one for you nitrous. my mallory Uni-lite doesnt have anything under the cap visibull that looks like wieghts or anything else to advance timing, how in thehell is this thing working so stinkin good? its gotta be advancing it somehow.

[dmorris1200]

Just cause you don't see it doesn't mean it's not there. Check this out-<a href="http://www.centuryperformance.com/mallory/marineuniassm.htm" target="_blank">web page</a>

[nitrous_69stang]

Thats because the weights are beneath the breaker plate.