Setting Timing

[bugedd]

Went to someone who knows much more than I about LBC's and after driving the car, he dug into it and found an intake leak at a fitting and a completely dead vacuum advance. Fixed the intake leak, getting a new advance tomorrow and installing it tomorrow night. Question is how to properly set the timing? I was told about setting to max advance the John Twist method, or just setting it to whatever factory specs are. What's the best way to go?

 

[dklawson]

Factory values from 40 to 50 years ago have little meaning as so much has changed since your car was new. The max advance method will set the timing as far forward as possible for the condition of your engine, its build, and the grade of fuel you are using.

I use the max advance timing method. Try it yourself. If you are not happy, you can always go back to using the factory specs.

 

[drooartz]

I've used the max advance method as well, with good results. 3500 RPM, vacuum hose removed and plugged, set to 32*.

If you're starting from scratch you may need to static time the car to get it running, then adjust it once it's warmed up.

 

[bugedd]

is there instructions on how to do this? And doesn't the car only have timing marks going to 12 or 15 degrees?

 

[drooartz]

I use a dial-back timing light. Set it to 32* and when the car pointer is at 0* you're set. They're not expensive.

The only bummer with the A-series engine is that the factory timing marks are on the bottom of the pulley. My wife and I have a method now: I'm on the ground under the front of the car with the light, with my legs where she can see them, she's in the driver's seat. Raise my leg, she brings the revs up to 3500. Lower the leg, back to idle. Not graceful, but it works.

Here's the basic procedure:

1. Unhook the vacuum line (if you have one) from the distributor. Plug the end of the hose (a golf tee works well) and the port on the dizzy.

2. Loosen the clamp that holds the dizzy in place, just enough that you can slowly rotate the distributor body.

3. Start the car.

4. Check the timing using your dial back light. You may want to paint the little notch on the pulley -- I used a little white paint I had lying around.

5. Adjust the distributor, and recheck the timing (I can't remember which direction of rotation moves the timing in which direction, someone here will know)

6. Repeat #4 until everything is set correctly.

 

[dklawson]

The only thing I do differently is that after letting the engine warm up at a normal idle, I adjust the idle speed screws to increase the RPM rather than have a helper do it with the throttle cable.

After setting the max advance you need to load test the car. What I do is accelerate hard uphill in too high a gear (4th when 3rd would be better). Listen for any knocking and pinging. If you hear any, retard the timing 2 degrees from where it is set and repeat the load test until no bad noises are heard.

With the dial-back timing light, it is easy to measure what your idle advance ends up being once you set the max advance. Write that down and you can use it later rather than having to go through the high-speed setting process.

I have a couple of dial-back lights. The one I like best is from Actron and it includes a built in digital tach. I got mine through Amazon since they had the best price at the time.

EDIT: And to advance the timing you turn the dizzy housing clockwise.

 

[Trevor Jessie]

Some old distributors develop weak springs and will max out their advance at a low rpm. I like to check the advance in 500 rpm intervals to get a rough idea of the curve to see if the distributor needs to be sent to Jeff for recalibration/rebuild.