© 2006 SEAMS

Starting

It was towards the end of spring 2005 that enough progress had been made to attempt a start. The Tangye patent petro-gas starting system had been renovated and new rings installed on the charging cylinder. After much discussion about the starting procedure some old books were produced and a procedure adopted. The piston was set in the correct position on the power stroke and with the con-rod at about 45 degrees to horizontal. The starter enables the cylinder to be charged with an air petrol vapour mixture which after isolating the starter, could be fired by tripping the ignitor/magneto to produce a spark. After many years of being idle, compression was not good and only a few revolutions of the engine could be gained by this method. A Guldner diesel donkey engine was rigged to turn the engine over and run in the rings. This worked to some extent but the engine is of such a size that there was barely enough power and the drive belt couldn't take the load. At that point, summer and the rally season had arrived so we retired to ponder our next move.  Towards the end of 2005 and the cessation of summer rally activities, work resumed on the engine and a Petter diesel donkey engine was permanently installed on site to drive the engine. A reduction drive from the Petter to the main Tangye drive pulley enabled a suitable rotational speed to be achieved and maintained.

Now we had a method to turn the engine over for starting, the fun started with attempts to provide the correct gas/air mixture to the engine. Producer gas is of very poor quality yet we had to run the engine on bottled gas, propane in this case. This is of much higher calorific value so less gas is required. It is also supplied from the bottle at pressure so again very little was required. Getting the right mixture on a regular basis for such a large engine was proving difficult. Two 'on demand' gas supply diaphragm type valves were made to allow gas to be drawn only when required and both types had some success but continuous running still proved elusive. Finally in February 2006, a gas valve operated from the main inlet valve was fitted to feed gas at the correct point in the cycle. After connecting a battery to the engine ignitor to provide a good spark (original magneto was under suspicion) the engine fired and continued to run. It settled down to run at a constant and regular speed under the control of the governor. When the battery was removed, the engine continued to run. That was a great moment which all those involved will savour for years to come though the ducks scared away by the sound of the exhaust may have another view...

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