Ignition Timing Light

[John Vardanian]

What do you guys use and is there a preference for the old V12's?

I have a couple of 1970's units, a Sun and and a Craftsman -- neither has knobs, buttons or adjustments of any sort. I am just wondering if I'm missing out on anything. Thanks.

john

[tyang]

Hi John,

I have both types of inductive pickup timing lights. If you have one with the knob, you can mark just PM/ 1/6 and PM 7/12 and adjust the knob to what you want to time. In other words, with TDC marked, you turn the knob to see AF 10 or AM 42 and the TDC mark will light up. With a fixed timing light, you need to mark all three marks to see them at the pointer.

Both work fine.

Tom

[John Vardanian]

Thanks Tom. Question, so, are you saying that with the non-adjustable gun you depend on your eyesight to dial in the timing, but with the knobbed one the gun tells you when you are right on the money?

Another question, while we are on this subject, do you or Sicard bother with setting the timing at the idle speed as well? I ask this, because , I just rev it up to 5000 RPM (while the distributor weights are swung all the way out) and set the timing on each bank, and that's that.

john

[tyang]

Thanks Tom. Question, so, are you saying that with the non-adjustable gun you depend on your eyesight to dial in the timing, but with the knobbed one the gun tells you when you are right on the money?

Another question, while we are on this subject, do you or Sicard bother with setting the timing at the idle speed as well? I ask this, because , I just rev it up to 5000 RPM (while the distributor weights are swung all the way out) and set the timing on each bank, and that's that.

john

Hi John,

No, you still need to look down that little window to see the marks. With a non adjustable timing light, I mark 6 positions on the flywheel: PM 1/6, AF10 and AM 42 and PM 7/12 AF 10 and AM 42. I use daub of white paint and another color for the 7/12 marks. With an adjustable timing light, you only have to mark two points: PM 1/6 and PM 7/12 and you turn the knob to 10 degrees, and 42 degrees and the timing light will light TDC (PM 1/6 and PM 7/12) to what you set the dial to.

We always set timing at AF 10 at idle, and check to see if we're getting 42 at higher rpms. If we're not getting 10 degrees at idle and the correct advance higher up, then something is wrong with the distributor.

Tom

[330Jim]

Tom's comments are similar to my experiance. If you get an adjustable timing light. I recommend one with the knob on the back. With the knob you can adjust the dial with your teeth while you hold the throttle at speed with one hand and the pull the trigger with the other. If you go for the button style, make sure you can work it with one hand. I prefer the adjustable lights to the non adjustable ones, especially with cars that only have timing marks for idle, but both will do the job. The adjustable just gives you more information easier. Get a good one, historically some of the cheap ones did not read the right timing.

Cheers Jim

[John Vardanian]

Yes, Jim, that's exactly the problem. You need three hands, one holding the gun, one pushing the throttle linkage and another on the distributor. I've often thought about a bracket that will hold the gun pointing to the flywheel while you use your two hands on the throttle and the distributor. It makes me nervous to have the motor spinning very long at 5000 RPM with no load on it.

john

[zac]

I know that my fancy overpriced Snap On timing light with the digital readout does not like Ferraris, I buy the 20$ analog ones from the parts store and I even have a battery powered one for Magneto cars since the charging systems seams to cause issues on some cars. One critical thing I learned long ago was that it is important to run a ground wire from the distributor to the engine while setting time since the only ground on the distributor is through the three nuts/washers that secure it so when you loosen them to turn the distributor it is possible to loose ground which will kills that bank.

Zac

[John Vardanian]

Absolutely right Zac. Without the ground wire you'll get sparks around the neck of the distributor and and erratic readings on the flywheel.

john