Purchased from a fellow enthusiast already restored and in working order, but a a few components including cooling tank are required to bring it back to original and working condition.

This type of engine is an early type of compression ignition (diesel) engine, but the temperature generated by compression alone is not sufficient to ignite the fuel when starting the engine from cold, so a portion of the cylinder head (hot bulb) has to be heated by blowlamp to facilitate starting - hence the term semi-diesel. Once started the engine runs without this additional heat source as the heat of combustion keeps a hot tube in the cylinder head hot enough (in combination with the heat of compression) to ignite the fuel when it is injected.

This side-on general view shows the boss for the starting handle, the large lubricating oil reservoir of the Calibrator lubricator and the distinctive cast exhaust silencer, typical of the Petter 2-stroke engines. This silencer gives the Petter 2-strokes their distinctive "Petter Pop" and often results in impressive smoke rings being blown skywards on still days.

Another distinctive feature is the Petter Calibrator mechanical lubricator whcih feeds lubricating oil to the cylinder walls and big end bearings. The lubricator is driven from a excentric on the crankshaft which converts rotary motion to a linear reciprocating motion which drives the lubricator meachanism via a ratchet mechanism. The twin brass component is the sight feed - the oil can bee seen to drip from the supply reservoir via the swan-neck tubes to the input side of the force feed pump - a visual confirmation that lubrication is taking place. This is normally covered by a glass pyramidal cover to keep dirt out. On this engine the glass cover has been lost, so a replacement needs to be found.

This view shows the cylinder head with its hot bulb, hot tube and Petter Patent starter holder which is essentially a holder for a smouldering taper which can be used instead of a blowlamp to provide the heat requirted to start the engine.

The engine's brass identification plate. No. = 202622 B.H.P = 5 R.P.M = 600 The remains of a Petter transfer can just be seen below the plate - don't know if this is an original.

This is the fuel pump - the red handle is used to prime the fuel injection system with diesel oil prior to starting. The handle used to prime the Calibrator lubricator is seen above the red handle.

This overhead view shows the fuel filter chamber and brass pump components with the lower half of the half compression tap in the top right hand corner (this is used to aid turning the engine past the compression stroke when starting the engine).

More to come when I get a cooling tank fixed up.

For a good history of the Petter S-type follow this hyperlink to Roland'sYard

**************************************