Triumph Herald 1360

As with many cars of the same era, subtle modifications on this Triumph Herald have been added over the years. After a full rebuild including uprated suspension and brakes, the owner of this car was looking for an increase in power.

Engine modifications including a change of cam and a swap to twin 40 Webers meant an ignition system upgrade was required. To get the best out of the car, a Canems Ignition ECU was fitted.

The owner of the car had sourced a nicely made alloy pulley, onto which a 36-1 trigger wheel had been fitted. The trigger wheel was an ex-Ford Sierra item, which was an excellent fit. Unfortunately these cars are getting hard to find in scrapyards nowadays but similar laser cut trigger wheels are available easily from a variety of sources, including the excellent www.trigger-wheels.com

It's often hard to get a smooth vacuum signal from car with Weber carbs. Like this Herald, most Weber setups only have one vacuum takeoff point, originally intended for a brake servo. For this reason, a throttle position sensor was used as a load sensor, rather than a MAP sensor which uses a vacuum reading.

Some simple fabrication work enabled a throttle position sensor to be mounted on the end of the carburettor spindle. Once this was physically in positon it was simply a case of calibrating the TPS with the Canems software. A reading is taken when the throttle is closed, and again when the throttle is wide open. The Canems ECU then knows what you are doing with the accelerator and adjusts the ignition advance to suit.

First Impressions

After initial fitment, the owner was very pleased with reliable starting and smooth idle characteristics - especially considering the state of tune of the engine.

Most people with Weber carbs remove the vacuum advance pipe from their distributor because there isn't anywhere for it to connect to on the manifold. There also seems to be a common opinion that removing the vacuum pipe is what you do on a 'racey engine'. On a full race engine, which doesn't need to idle or be driven in traffic this is fine, but lack of vacuum advance will not help the engine to idle at all well. As this Herald had a load sensor, the idle characteristics could be transformed just by changing the advance figure by a few degrees.

The car will be heading to the rolling road once the engine has been run in - it'll need the carbs setting up correctly. It'll be interesting to see what figures the engine produces and how much difference the ignition timing makes on this particular engine....

Rolling Road Tuning

With the engine sufficiently run-in, and the reliability of the rest of the car proven, the Herald was booked in for a rolling road session at Bogg Brothers in East Lutton near York. After adjusting the Weber carburettors, several changes were made on the Canems ignition map. Retarding the ignition timing slightly at low speed helped to bring down exhaust emissions, reflecting a more efficient combustion.

After slowly building up to some full power runs, a suitable maximum advance figure was decided upon. With the Canems ECU programmed correctly, it was time for the moment of truth.

The final power reading showed a very respectable 80bhp at the wheels, translating to approximately 95bhp at the flywheel. This should make for a great road car, and above all, the Canems ignition system will give dependable running whenever the car is used.