AC Powered Engine Timing Light

Back in the 1970s I wanted a xenon timing light to replace the nearly useless neon timing light I had. I borrowed a friend's AC powered timing light to use. While I had it, I opened it and made a diagram of the circuit. Then I went to an electronics supply store and got most of the parts. I got the lens and the xenon flash tube from Sears. To do that, I took the model number from a new unit on the shelf and went to their repair parts store. In a few minutes I had the part numbers I needed and ordered them. Today you can use an Internet search to find replacement parts for xenon timing lights. I decided on an AC circuit because the circuit is simpler and because I can use the light on machines with a magneto ignition where there is likely no battery.

Once we had a yard full of gopher mounds. The soil was clay. When I hit one of those with my mower, it often sheared the flywheel key. I eventually put timing marks on that mower so I could check it with this timing light before tearing the motor apart and learning it was not running for some other reason.

Be careful: this circuit makes use of high voltage. Before handling internal parts use a screwdriver with a plastic insulated handle to remove the charges from the capacitor by shorting out the case or ground terminal to the "+" terminals of the capacitor. Do this a couple of times to be certain all charges are removed.

The paint was from an aerosol can of touch up paint for a 1963 Chevrolet.

Step 1 A wooden case

I made the case from plywood. I began by cutting a pistol grip base from two pieces of 3/4 inch plywood. I made recesses for the trigger switch, the AC power cord, and for the copper core spark plug wire. There is a hidden pivot pin in the 1/4 inch plywood trigger.

Next I cut and glued the right side panel to the side of the base. Then I framed the light with a back, top, and front. The front has a hole for the lens.

You can also see wedges to hold the wires in place in the pistol handle.

Comments

[The Lightning Stalker]

Old TVs and monitors are a good source for the parts. You can get Xenon tubes on the Internet or a place where they sell strobe lights.

[Phil B]

I did not have access to any old television sets at the time, and have rarely had access to any since. But, it is a good idea. I remember doing some research on the matter at the time and there was a difference between xenon tubes for party strobe lights and xenon tubes for engine timing lights. I no longer remember what it was, but I passed on the xenon tubes at Radio Shack because they did not meet the appropriate specs. Thanks for your comment.

[stormende]

Sweet, a blast from the past!

I do remember my father had one of this timing lamps but if I recall right, the light was redish meaning it was some kind of neon, isn't?

Anyway, congrats for such a nice instructable.

I gave it 5!

[Phil B]

Your father's timing light was almost certainly a neon timing light.  They were  inexpensive and required no power other than the current for the spark plug.  They also gave very little light and worked better used inside a dark building or after the sun had gone down.  I had one for a while and taped it to a stick so I could get its light closer to the damper pulley with the timing marks, but without getting my hands into the engine's belts and fan.  In the late 1960's a neon timing light cost about $5 US.  The AC powered light I copied for the light shown in this Instructable cost $20 US.  A nice DC powered timing light powered from the car battery was about $35 US.  The legally proscribed minimum wage was about $2.75 US and gasoline was about 34.9 cents a gallon.  You can easily see why not everyone had a powered timing light, AC or DC.  Thank you for your comment and your very favorable rating.

[mortaz]

thanks for you and keep it on, do not let any thing to stop you becoase its been sold for more than 100$

[Phil B]

Mortaz, Thank you for your comment. If the line voltage where you live is greater than 120 volts, say 240 volts, you would need to use electronic parts capable of using higher voltages without failing. Instead of parts rated at 300 volts, you would probably need parts rated at 500 to 600 volts.

[Phil B]

Thanks. I have posted a bunch of stuff I did over the past 40 years. Take a glance at some of my other Instructables. Not so many people use timing lights anymore because of changes in auto design. Even fewer have heard of an AC powered timing light. But, there still are times when one comes in very handy, and an AC powered light is pretty easy.

[grantaccess]

Very cool. I love hearing about pre-google hacks.