Petter PA2C compressor engine

Posted by Chris Graham on 21st March 2022

Martin Westbrooke introduces his Petter PA2C Compressor Engine, and provides some background about the machine and the company that built it.

Petter PA2C compressor engine

My Petter PA2C compressor engine, as acquired.

I recently purchased a small batch of cheap engines online, one of which I assumed to be a two-cylinder petrol Petter PA or PH. I was, however, puzzled by what appeared to be a single muffler on the single image viewed. Upon collection, this was explained as it was a compressor unit.

Petter engine maker’s plate.

A search in my copy of A-Z of British Stationary Engines revealed that PA2C, AV2C and PA2WC Petter-Reavell compressor units were built in the 1952/53 period. My example would appear to be a PA2C but, as can be seen on the maker’s plate, it’s only marked ‘AC’.

Petter PA2C compressor engine

Petter M type-driven Reavell compressor.

The compressors were made in association with Reavell & Co., of Ipswich. This company was founded in 1898 by Sir William Reavell, specialising in steam engines and compressors. With a good reputation for durability and quality, Reavell compressors were used during the construction of the London Underground, the infancy stages of submarine warfare and the starting of diesel engines on British battleships and transatlantic ocean liners. On the Heritage Machines website Patrick Knight describes a 1926 Petter-Reavell compressor based on an M type in New Zealand, indicating Petter and Reavell had a long-standing link.

Petter PA2C compressor engine

Power and compressor cylinders exposed.

The engine I purchased was in scruffy condition, with peeling yellow paint over the original green. Removal of the top shroud confirmed it to be a Petter-Reavell, with a Reavell plate below the compressor cylinder.

Here we see the engine and compressor after cleaning and painting.

A normal service of the Wico impulse magneto produced a good spark and the Zenith carburettor was given a good clean and the engine returned to its original green colour. The 486cc engine, with 274cc compressor, is rated to produce 100psi continuous at 6 cu. ft/min.

McLaren MR4 multi-cylinder engine, with Petter PAWC as seen at the Pioneer Park Museum, Dalby, Queensland.

The only other example shown on the internet is a water-cooled example, assumed to be a PA2WC, linked to a McLaren MR4 MK11 engine at the Pioneer Park Museum at Dalby, in Queensland. It’s used to charge the air-tank for starting the McLaren. It is noted that J&H McLaren Ltd. had an association with Petter Ltd. as part of the Associated British Oil Engines group. The Dalby Pioneer Park Museum has a large collection of working farm machinery.


Knight, P. (1999). A to Z of British Stationary Engines Vol 2. Kelsey Publishing, Cudham, Kent.

Dalby Pioneer Park Museum.

Petter Ltd. (undated). “Petter-Reavell Air Compressors PA2WC and PA2C Operators Handbook”. Publication 2077.

1926 Petter-Reavell compressor unit

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