The black clamp connects to the battery -, the red clamp to +, the green one to the breaker side of the coil (for RPM), the big black clamp in the foreground is an inductive pick-up that clamps around a spark plug wire.Ī timing light is a stroboscope used to dynamically set the ignition timing of an Otto cycle or similar internal combustion engine equipped with a distributor. Spark cross over from other wires can easily influence timing light performance.Timing light, combination instrument with RPM, volt meter and dwell angle meter. Number One ignition wire must be well separated from the other wires on the engine. Never use the coil as a source of timing light power. In the event that your race car has a trunk mount battery or pair of batteries, add a power junction block to an accessible location in the engine compartment. It’s reliable and accurate.īoth timing light power cables should be affixed to the battery. This is an old Sears timing light I regularly use.

We’ll look at the right way to use your timing light, because, believe it or not, there are some misconceptions out there.

Next issue, we’ll look at ways to test your timing light.

Before you purchase such a unit, compare it to a known timing light. Many of these adjustable timing lights also carry very high price tags. Most home-use timing lights have little if any protection against RF noise and as a result, can produce erroneous readings when used in conjunction with solid core wire sets.Īccording to MSD research, certain types of timing lights with built-in adjusting mechanisms (usually the common “dial back” models) have been proven to be so inaccurate that they produce false readings at speeds in excess of several hundred RPM. Another real problem is radio frequency noise protection. This has little impact in the lower engine speed ranges, but once the RPM level goes over the 2,000 RPM range, timing lights with delay circuits appear retarded. In some instances, a trigger delay is installed in the light (this practice is even found in some very high dollar “professional name brand” lights. As a consequence, many timing light manufacturers are able to construct a very simple, cost-effective timing light. Most tune-ups (professional and otherwise) seldom, if ever, require that the timing be checked beyond 2,000 RPM. While it might come as a surprise to most serious racers, some (no, make that many) timing lights are not accurate! The reasons are varied, but in the majority of cases, timing lights have been designed for use in “more pedestrian, Mom and Pop” applications. Correctly indexed harmonic dampers, as well as properly indexed timing tabs, are crucial. The only real problem with setting up timing in this manner is the fact that your timing equipment must be absolutely accurate. In order to establish this synchronization, you use a timing light to determine piston position relevant to a number of degrees marked on either the harmonic damper or the timing tab. Before we get into lights, think about this: The idea behind setting initial timing is to synchronize the firing “point” of the ignition with the position of the piston in the cylinder bore. It runs right It doesn’t sound like it’s detonating What more do I need to know?” There’s no question that timing lights are anvil-basic devices and are easy to use, but contrary to what you might first think, all timing lights are not created equal. “Who cares about timing lights? I’ve timed the engine in my race car a thousand times.