The main limitation of the timer used in
the Model T ignition system is that it is a mechanical switch. It is an
unfortunate feature of any mechanical switch that wear will take place
because of the friction of contacts moving against each other. This eventually
reveals itself in the form of intermittent connections and, and in the
case of a Ford timer, poor timing. Many timer designs were developed in
the Model T era, each supposed to be an improvement on its rivals, but
the problem still exists to a lesser or greater degree.
It was of considerable interest therefore, when an electronic timer became available. Like the ECCT which I reviewed here, the E-Timer was also developed by Mike Kossor in the U.S. I have been able to try one out, and familiarise myself with all the aspects of installation and performance.
What is the E-Timer?
In simple terms, the E-Timer is a drop in substitute for the mechanical timer. It looks the same, being built into an Anderson timer casing (although for the purist can be built into the original roller timer casing), and uses the original wiring and coils. Unlike distributor or True-Fire conversions, once installed, the E-Timer installation looks completely original in every way.
There are no mechanical contacts in the E-Timer to wear out or need cleaning.
In place of the timer’s mechanical contacts
are transistors that switch each of the coils in turn. Cam shaft position
is determined with a magnetic Hall-effect sensor and rotating vane. Included
in the circuity is a microprocessor which provides a number of interesting
features, such as automatic timing advance, and the ability to take over
the points and capacitor function of the coils. What this means is that
your coils do not need to have functioning or correctly adjusted points,
and nor does the capacitor need to be in good order. Only the coil windings
need to be functional. This aspect of the E-Timer is a huge advantage for
those who are unable to rebuild or correctly adjust their coils, but who
prefer the original Ford ignition.
Because there are no moving parts that can wear, timing is always perfect, and will remain so indefinitely. Neither will the coils have to be adjusted ever again. In effect, the E-Timer is providing all the advantages of electronic ignition, but with keeping the original four coils and wiring intact. It is a perfect example of how modern technology can improve the Model T without actually changing the car.
This rotating vane interrupts the magnetic field picked up by the Hall-effect sensor.
The E-Timer is designed to work with 6
to 12V negative earth electrical systems. It will not work directly from
a magneto’s AC output. For those with pre 1919 cars, it will be necessary
to provide a small battery, but these already exist in most cars for turn
signals and brake lights. Due to the low current consumption of an E-timer
ignition system, it would be quite sufficient to recharge the battery at
home after driving. However, fully independent magneto operation is still
possible using a suitable AC to DC power converter. The E-Timer is not
to be confused with the True-Fire; the latter being a complete replacement
ignition system which does not use the original coils.
If direct magneto operation is desired, the I-Timer is now available.
Although the E-Timer is a drop in replacement, there are some important things to be attended to. The clearance between the rotating vane and sensor is small, so it’s essential that the timing cover be centred correctly, otherwise the sensor may be damaged. A properly centred timing cover is just good practice anyway, even with a mechanical timer.
The instructions recommend a neoprene camshaft seal, but for my initial tests I kept with the original felt type, as I knew the leakage was minimal. Indeed, after two months of running there were only a few drops of oil in the timer casing. Subsequently, I did install a neoprene seal in view of an E-Timer being a permanent fixture in my car.
The timer connects to the wiring harness
in the usual way, but as with other U.S. sourced timers, it is installed
upside down in our Australian assembled Canadian RHD cars.
This means that the labelling for the coil terminals is 180 degrees out. This in itself is not a problem, because the firing order is the same, but one needs to know which particular coils are connected to which terminal, as will be explained later. However, the E-Timer can be supplied with the internal circuit board upside down to conform with normal wiring in RHD cars, if this is preferred.
A purist cannot tell this car has an electronic timer.
Because the E-Timer also takes the function of the coil points, the instructions explain how the coil points are bridged out. Four fusible links are provided for the purpose. Purists can install these inside the coils so they’re not visible, or they can be simply placed under the nuts on the coil tops. The links are fusible to protect the wiring of the car, and the coils, if there should be a short circuit in the wiring to the timer. They will also protect the coils should they inadvertently be put into a car with a mechanical timer.
The reason for this is that with points bridged out, there would be nothing to limit the current if full battery voltage is applied to the coil, as the points opening will no longer disconnect the supply. Despite the coil points being bridged out, they still buzz with the E-Timer because the magnetic field in the coil core is still being rapidly interrupted. From an electrical point of view the points are now superfluous and not required, unless for appearance or to retain the sound.
It can be seen that with the points bridged out that the capacitor is also bypassed. What this means is your original 100+ year old coils can be used in "as found" condition at full efficiency. Even if the original capacitor is completely short circuit or open circuit, it does not have to be replaced.
Although the E-Timer was designed to be used with bridged out coil points, it is possible to use it with the coil points still active, and not install the fusible links. This is how I use the E-Timer. The caveat here is that the coils must be set for equal dwell time on an electronic tester, such as the ECCT; otherwise the timing accuracy of the E-Timer may be negated. Set up thus, I don’t have to touch the coils when changing from the E-Timer to a mechanical timer, and vice versa.
The E-Timer and the ECCT.
The question may now be asked, what if I've already invested in an ECCT? Will it no longer be required? The answer is no. By using your ECCT to set your coils, it means you don't have to bridge out the points, making the coils instantly transferable to another car without modification. In effect, it's the best of both worlds with the E-Timer being a direct drop in replacement; no modifications needed. Swap between the E-Timer and mechanical timer as much as you want with absolutely no modifications.
Furthermore, your ECCT can continue to help the ongoing demand for coil repair from those using a mechanical timer.
However, unless the owner has a thorough understanding of the ignition system and coil dwell time, or does not have an ECCT, the recommended instructions for bridging the coil points should be followed.
Decrepit coils like this will work perfectly with the E-Timer provided the windings are good. The points and capacitor are optional.
I set the initial timing like I would for a mechanical timer, and most Australian owners do so – that is, for the No.1 coil to buzz just as the piston starts to leave TDC. However, it has been the custom in the U.S. for initial timing to be set to 15 degrees ATDC, and the instructions go into detail on how to do this. If in any doubt, follow the instructions provided – you don’t want a “Ford fracture”!(i.e. broken wrist/arm).
For my installation, I did not have to adjust the timing rod after previously using Anderson and TW timers, but it was still essential to check this.
Finally, the timer is ready to be programmed for either manual timing, or automatic timing. With manual timing, you drive using the timing lever in the usual way as when running on battery, but in the automatic mode the timing lever is left fully advanced once the car is started. The microprocessor in the E-Timer measures engine speed, and retards the timing as necessary.
Programming is done in a most ingenious manner. There are no switches or links. Instead, all but one of the coils is removed, the ignition turned on for five seconds, and the other coils replaced. Hence, the need to know which coils are connected to which terminals on the upside down installed timer. Depending on which coil is left in situ, the E-Timer knows which timing mode it should be in. It stays in this mode indefinitely unless the programming is changed again. By default, the E-timer comes with automatic timing selected, so the programming step is skipped if you prefer this mode.
How does it perform?
On my first power up of the ignition system with the spark plugs laid out on the cylinder head, as required to safely verify correct timing, the improvement in spark quality was clear. Because the coils are now being switched by the E-Timer and not the points, the raspy and varying note of the buzzing points was now a consistent smooth buzz.
Starting the car seemed easier, and this was on a cold day. It was noticed that the idling was smoother and quieter. So far I was quite impressed, but the real test would be to take it out for a drive.
Immediately, the difference was obvious. The smoothness over the entire rev range was something that I had not experienced with a mechanical timer. Clearly, this could only be a good thing in terms of bearing wear. As a result, the engine just ran quieter.
The most noticeable thing however, was the much improved low end torque.
On a flat road it was possible to drive the car just above idle speed and almost count each cylinder firing. With this improvement, it was also found possible to change into top gear sooner than normal.
In terms of top speed, this was the same as I get with a mechanical timer with coils running on 6V; i.e. about 75 km/h.
After the initial excitement with the improved performance, it was time to do some other tests. As mentioned previously, my coils were set on an ECCT and the points were not bridged out. For the sake of completeness, I tested the E-Timer with the coil points bridged out. For this test, I found four coils of unknown condition, some with no points, and one even with a missing wooden cover (see pic above). With windings tested, the point connections were bridged and the decrepit coils put in the car. Needless to say, the car performed perfectly. I could not detect any difference between the coils with the unbridged and bridged points.
The final test was to compare the two modes of timing. Initially, I had been driving with the timing on manual, so as to give a better comparison to what I have been used to. In this regard, the timing lever is adjusted exactly the same as with a mechanical timer. I programmed the E-Timer for automatic timing and went out for a drive on the same hilly route I’d used for the previous tests. It certainly does work, but feels strange at first climbing hills without backing off the timing lever. Unless you know your car’s optimum timing settings very well, I would say the E-Timer does a better job in this mode. The length at which hills could be ascended in top gear was impressive. I spent a few weeks driving around with the automatic mode and became quite used to it, but my preference is to adjust the timing as I drive, so I set it back to manual. For someone new to driving Model T’s, the automatic timing would very obviously be an advantage.
Automatic timing mode makes it more difficult for a beginner to stall the car since the E-Timer will sense the low RPM stall condition and immediately suspend automatic timing mode, automatically retarding timing. Once all the other aspects of driving a Model T have been mastered, then the timing can be adjusted manually if desired.
Without a doubt, I vastly prefer the E-Timer over the mechanical timer, not just in terms of the improved performance, but for the consistency of this performance, and knowing it will stay that way. While the cost is higher than that of a mechanical timer, it’s like a new radiator – once you’ve installed it and seen how good it is, the cost becomes irrelevant. It is full electronic ignition performance, with perfect timing that never needs maintenance, yet uses the original Ford coils, wiring, and coil box. No other ignition system used by Model T owners can provide all these features. For those wanting a more in depth description of the E-Timer, I recommend Mike Kossor’s site http://www.modeltetimer.com/
Now available for those who wish to retain direct magneto operation is the I-Timer ("Ideal" Timer). This is a development of the E-Timer and is so named because it mimics more closely, the original mechanical timer in operation. Basically it differs from the E-Timer in that Triacs are used instead of IGBT's to allow operation from the magneto's AC waveform. It does not however, include the automatic timing feature. Also, the coil points are not bridged out, and therefore coils must be adjusted correctly. Because the coil points are functional, it means that the I-Timer can also be used on battery - the opening of the points is required to reset the Triacs, which would otherwise latch on with DC.
However, although the I-Timer can run directly from the magneto, a battery is still required for starting.
|Mechanical Timer||E-Timer||I -timer|
|Direct magneto operation||Yes||No||Yes|
|Coil points need to be bridged||No||Unless set on ECCT||No|
|Capacitor needs to be good||Yes||Not if points bridged||Yes|
|Coils must be correctly adjusted||Yes||Not if points bridged||Yes|
Which of the two electronic timers suits the owner best depends on several things. For those who cannot adjust or repair their coils, or who want automatic timing, the E-Timer is obviously the preferred choice. For those who prefer direct magneto operation and manual-only timing, and can set their coils correctly, the I-Timer is the one to go with. If the magneto fails, the I-Timer will continue to run on battery in the normal way.