cmg1

What problems are caused when an engine is not timed correctly and how to hook up timing light for 1973?

Thanks for the help.

Techno

Too much advance.
Hard starting
Overheating
Pinging
Loss of performance
Bad gas milage
Engine damage


Too far retarded.
Slow to start
Loss of performance
Bad gas milage
Engine damage-if it does start.

Both depend just how far off it is.

like any other.
2 power wires to the battery. red+ black-
If its induction light then an opening clamp like thing on the #1 wire. If not then it plugs onto the #1 spark plug and the wire plugs into it.
Disconnect vacuum advance hose and plug(plug the carbs vacuum not the distributer) Set timing to desired amount.

As a note. The best way to set your timing is without a light. You do it by driving the car and retard timing about 2* from ping. This is done with every thing hooked up (not the light though).
I forgot to mention that you floor it. No ping advance timing(small amounts) and repeat, finally when it does just ping retard it.


[Modified by Techno, 8:59 PM 12/30/2001]

lars

Techno -
You might want to add that for the "power timing" technique to work right (and it does work very well) you have to use the correct octane rating fuel for the engine. In other words, if you put 100 octane fuel in a '74 low compression engine and try power timing it, you may never get it to ping, and you can end up overadvanced. For that reason, I usually recommend checking the total mechanical timing with a light after having done the power timing, just to make sure that an over-advanced condition has not been obtained. If you're beyond 38-40 degrees, chances are good that it's a bit too much. What's been your experience?

Vetterodder

If the goal is making the most power, power timing is only effective if you are on a dyno or making back to back timed runs so that you can compare the results. As Lars mentioned, the most timing an engine will tolerate without pinging isn't necessarilly the timing that makes the most power. Each engine will produce the most power at a certain advance and more or less will result in less power. Just because it doesn't ping at a certain setting doesn't mean that it's the right setting. Even identical engines may respond differently to advance due to other factors such as carbon build up, variations in octane, etc.. Power timing is useful in setting timing on a high compression engine that can't get enough octane to prevent damage. In that scenario, you are looking for a compromise setting that won't cause ping or detonatiion but that is lower than recommended. While over-advance can increase extra heat, retarded advance is much more likely to cause over heating.

redwingvette

As Lars said. For a 73, The factory distributor were: 12* at idol +14* mech. + 15* vacuum. If no one has changed it you will get better performance if you use Lars suggestions but the idol set point will be very high. Lars recurved mine and I am Very Happy with the results ;) . I use mine for daily driving during the nice weather and some long road trips. I attach the timing light to the alternator + and ground to the engine.

AFunderJack81

:sleep:

Captain Morgan

I do too since the timing light cables aren't long enough to reach the battery.