Interesting... I thought of building the same thing after making my own LED light with some alligator clips to help me set the timing. A built in unit that was always on, coupled with a clear cover could have a cool looking effect.
Couldn't you purchase some surface mount leds and somehow attach them to the back side of the timing plate (epoxy?). A few of them around the hole on the back of the plate should do nicely.
I'm not sure if I like the spring loaded switch. I think I'd prefer the locking type so I'd have my hands free to focus on adjusting the timing plate.
How would this effect the accuracy of setting the time vs. using a timing gun? I assume it's effectively the same, but I figure the timing gun would be slightly slower (probably not enough to make a difference?)
The LEDs are about 250 times faster (ON time measured in nanoseconds vs. milliseconds for a strobe fire circuit) than a timing light, so in that regard it will work fine. The reason for the spring switch is the limited current available to the LED at speeds over 3500 RPM: it gets real dim then. My Transistor Ignition limits the power to the points to 120mA, and these ultra-brite LEDs use about 60mA in a flash. So, if the engine is revved up beyond about 3500 RPM with the switch held ON, the spark can become pretty weak, and the first thing that goes 'out' is the LED.
The intent of the gadget is to simply and easily check the timing. The points don't wear anywhere nearly as much as some folks argued they would (if you can find the thread back in 2006 when we developed this thing here, you'll see the opinions), which I knew would not happen - from past experience with it. So, I started to make this gizmo way back when, but the expense of making a mount for it is almost 12x as much as the parts(!). That's why I haven't brought it out as a 'product' so far.
Since the anticipated wear factor was to be the points foot rubbing wear, the check can consist of simply flicking on the switch for the desired side at idle or full advance, and taking a peek to make sure it's on the marks. It's that fast. Thing is: in the 6+ years I've had mine running, the timing hasn't moved, period. The gap never changed and the foot didn't wear, because there is no arcing. It's the arc/weld/break-open cycle that makes them wear out, both at the tungsten and the pivot: without the arc, there is no weld, and since they are designed to take that abuse but don't see it now, there just isn't any wear, either.
I found that I can make all the parts available for about $15, until it gets to the bracket. That thing costs about $10 each to have made, plus a setup CNC charge of $400 at a sheet metal shop. I don't think there is much 'value' in a $35 LED timing light that will show the points never shifted in timing, hence my reluctance to bring it out. I sure have a lot of parts from before the 'reality check' though!
For the folks who want 'glitz' it is easy to nab some from the back-blast of the coils. We used to hook up neon bulbs to the points, much like the old Maxi-Dwell units, to show a flicker while running, then hooked them to the forward downtubes for a night light show. There even used to be a circle of 8 neon bulbs in the tach console of the Shelby GT500 Mustang console that picked up their trigger from the individual sparkplug fires on those monster 650+ HP Cobra FE 428 engines (one of my college buddies had this arrangement in his GT500KR). In 1969, that was COOL!
