Hot tube ignition

The Panhard’s original ignition system was a ‘hot-tube’ system. A tube, heated from the outside, protruded into the cylinder at about the position occupied by the spark plug today. When compressed by the piston in the cylinder, the fuel mixture was pushed against the hot tube and ignited spontaneously.

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To start the car bunsen type burners inside a ‘firebox’ beside the engine were lit using methylated spirits to heat up the platinum tubes until the ends became red hot. 

The burners were then fed from their own regulated fuel supply contained in a tank embedded in the back of the driving seat.  The pipe-work is still visible.

The doors to the firebox were kept closed when driving, to shield the flames. If they blew out, the engine would stop and the fires had to be re-lit to start the engine.  

The museum still has the Panhard’s original burners. 

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The timing of the combustion in the four cylinders was achieved by variations in the length of the hot tubes and position of the burners but this was not very accurate and not adjustable.

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