Anderson Timer- technical question

[Bill Robinson]

I am in the process of "fine tuning" some Anderson Timers that I own and I need some dimensions.
Look at the image-
A- I need the distance between the point of contact on the terminals where the flapper strikes the terminal.
B- I need the distance between the point of contact on the terminals and the inner rim of the timer case.

Thanks- hopefully, by doing this I can achieve all 4 cylinders firing at the same exact spot on a degree wheel.

[DanTreace]

Measured a new rebuild of an original ANCO, rebuilt by Tip Top Timers.

The A distance from top surface across two contacts is 1.255"

The B distance from inner edge of timer shell to top of contact surface is 0.530"

[Plankhill]

I have found that the only way to set up an Anderson timer is to measure the degrees between contact during rotation. I have a degree wheel set up on a old block, cam and crank. Wires with clips go from the timer to a light bulb. When the timer flapper makes contact the bulb lights up. I then bend the timer contacts until I get it to fire at the 90 degree points. Some of them out of the box are 5 degrees off. Also make sure they can reverse rotation without catching the contacts and advancing the timing.

[Bill Robinson]

Many thanks Dan!

[John kuehn]

What would make them off. Maybe the thickness of the inside contact insulators?

[TXGOAT2]

I don't have any experience with them, but it looks like how tight the terminal stud nuts were could affect the position of the contacts, and any tendency of the contacts to turn when the terminal nuts were tightned could affect timing. Maybe some kind of jig could be made to hold the metal contacts in position while the nuts were tightened. A plug gauge marked every 90 deg. could be used to align the contacts. A new timer might be more stable if it was run a few dozen miles to let the insulation take a set. Then snug up the terminal post nuts and make any needed adjustments.

[John kuehn]

As I remember Frank Fenton was the guy I bought an Anderson timer from several years ago
at Chickasha. He had a display board set up showing the accuracy of the timing and firing of an Anderson. Seems like he was the first one making a quality reproduction of the Anderson. He was a really knowledgeable guy who would rebuild an original.

[Bill Robinson]

As you know, the ideal situation is to have the contacts positioned in such a way that each cylinder fires in the correct order (1-2-4-3) and for each cyl to fire at exactly the same time (90 degrees apart) on a degree wheel. This makes a smooth-running engine. If any cylinder fires 10 degrees (for example) different from any of the other three, then a vibration is set-up to drive you crazy and is hard to find. My goal is for all 4 to fire at exactly 90 degrees apart, which is only possible if the factory measurements are known and set.

[TXGOAT2]

Due to manufacturing irregularities and the "give" in the insulation pieces, you'd probably find it easier to use a degree wheel and fine tune the individual cylinder timing that way. Some variability would probably occur in the rotor parts, too. A couple of hours time in service might be a good idea before trying to fine tune a new or rebuilt timer. Once the mechanical parts wore in, they'd probably hold a fine adjustment better.

[Art M]

I am thinking about buying one of these timers. I am getting tired of cleaning my much loved roller timer. The last one from Synders is holding up much better than ones I had been using.
As purchased the timer will take time to get it properly adjusted.

Art Mirtes is

[Steve Jelf]

I'll take this opportunity to state the obvious. All mechanical timers — roller, flapper, brush, whatever — are subject to wear. The roller and brush timers have the advantage of contacts built into the case 90º apart so they can't get out of adjustment.

[Bill Robinson]

Pat- I've been using a degree wheel for a while now. I make a chart for each T. Ones like it have worked fine on my T's and some of the members of the club that I'm in. Even though the one in the image is a home-made version, the original version was a digitized copy that I found on one of the forums.

[TXGOAT2]

It would be informative to test the several types of available new timers on an engine with known good coils and good cam bearings and running at various speeds. With an oscilloscope, or perhaps even a timing light, the stability and firing consistency of each type could be measured. Testing used examples of each type with known hours of service would also be useful. Just looking at pictures, and lacking any experience with them, I'd think the Anderson type might be more subject to timing errors than the New Day or Ford roller type.

[Jerry VanOoteghem]

As I remember Frank Fenton was the guy I bought an Anderson timer from several years ago
at Chickasha. He had a display board set up showing the accuracy of the timing and firing of an Anderson. Seems like he was the first one making a quality reproduction of the Anderson. He was a really knowledgeable guy who would rebuild an original.

Frank Fenton bought the Anderson Timer business from Bob Thompson in Michigan. Bob was the first to reproduce them. Frank, however, was an excellent choice to continue the great work begun by Bob.