Timing Light - Which One?

[tom_sprecher]

I have an old non-adjustable timing light that works fine albeit not too bright (much like its owner) . How do the "adjustable" units work. Can you dial in how much timing you want and when set correctly the TDC mark on the pulley will line up with the pointer?

TIA

[JeffYoung]

Craftsman dial-back.

When you get the motor's timing "all in", say around 4,000 rpm, you dial back the dial on the light until the timing mark reads zero. At that point you add the number on the dial to your static timing amount and determine your total advance.

Or at least I think that is the way it works.

[Ron Earp]

Tom you got it. On the dial back light the number you dial to get the crank and timing marks to zero is the total advance - no adding needed.

I don't ever look at the static timing any more, it is irrelevant. Set the motor up on the advance you need at high RPM and static falls where it may.

Now, in Jegs or Summit I saw a cool thing, a timing pointer with integrated timing light. Would be useful for cars like, say, TR8s, where the battery is in the trunk and I can't ever get any power for the timing light. Not a dial back design though so you'd need to tape up your balancer to get beyond 10 degrees or so for most cars.

[Greg Amy]

"Timing light"? Why not just go into the ECU program and edit the timing table to give you the total advance you're looking for...?

Hey, just askin'...


<grin, duck, run>

[Ron Earp]

Damn, I didn't know my steering wheel mounted $2.99 stopwatch had that feature. I'll plug it into my laptop next race and tune my Z motor!

[CRallo]

what you add to what depends on what the marks are referencing. the only time you'd add anything together is if the marks were not on zero...

what works best is to put clear visible lines using "white out" or a white (or yellow) paint pen on both marks. some pointers have the degree #'s and some balancers or pulleys do, but the important part is to mark 0 degrees and the indicator(usually TDC) line. Often time these marks are not easily visible or clear. Using a timing light like the one you are refering to allows you to simlify things and just use a single clear mark on each surface. when these line up, the timing is whatever the dial says.

exact procedures for testing will depend on the application. REMEMBER: in most cases the vaccum or computer advance mechanism will need to be disabled... also base timing is easily checked at idle, while total timing will be checked at a higher RPM usually atleast 3000 but often over 4000.

the craftsman light that has the dial is the "profesional" one and runs around 70 or 80 bucks i believe.


initial timing can also very important, but slighly less so for racecars. it has a large bearing on vaccuum output at idle, the smoothness and quality of the idle, as well as the engine's ability to (re)start hot. the last bit, of course, is very important...

[shwah]

I run static timing, and set it at 31.5 deg at idle.

As noted turn the knob until the 0 mark lines up, and look at where it ended up. OR set the knob where you want to end up and turn the distro until the 0 lines up.

[spawpoet]

Damn, I didn't know my steering wheel mounted $2.99 stopwatch had that feature. I'll plug it into my laptop next race and tune my Z motor!

You can tune a z motor?????????!!!!

[Ron Earp]

You can tune a z motor?????????!!!!

In a liberal sense I suppose you could refer to my shuffling various parts around until it runs and doesn't catch fire "tuning".

[tom_sprecher]

My 7 has both vacuum advances disconnected and seeing no advance happening as I rev'd it I have to say the centrifical advance is disabled as well. Since both are "all in" at about 3000 according to the factory manual maybe that's fine since the engine rarely see less that 4k and starts very easily.

So, if I got an adjustable timing light, set it at say, 24 degrees, ran it up to 4k and adjusted the distributor so the pointer was at 0 degrees that's all there is to it?

If so, I gotta get a new light or go through the hassle of marking the pulley for 20 degrees and up at 2 degree increments. Scratch option #2. Besides Craftsman and "I can't afford it" Snap-on, anybody have a recommendtion on a good timimg light.

[Ron Earp]

So, if I got an adjustable timing light, set it at say, 24 degrees, ran it up to 4k and adjusted the distributor so the pointer was at 0 degrees that's all there is to it?

That is all there is to it as long as the advance is disabled and your timing marks are correct. You might want to rev it on up to redline and watch what the timing does to make sure it remains steady and doesn't dial itself some unwanted retard or other such foolishness.

I have the Craftsman unit I bought and fixed one of Jeff's Car Quest cast off units. For Jeff timing lights are one use items. Both work well. I have also used this $29 wonder from HF and it worked too:

http://www.harborfreight.com/cpi/cta...emnumber=40963

[C. Ludwig]

Ferret timing lights all the way! I've used up a couple Craftsman. They lasted longer than the two cheapos I began with. All would work when new but became progressively less reliable over time. I bought a well used Ferret for less than the price of a new Craftsman on the advice of more than a few mechanics. It's feature packed and give better results than anything I ever had that was fresh out of the box. I the coil is firing you see a strobe every time. No more playing around with the pickup hoping it does it's job.