SUCK : SQUEEZE : BANG : BLOW

Let's get this clear straight away. Suck, squeeze, bang, blow is a well-recognised  and perfectly legitimate technical expression. 

 

It's all about the workings of the internal combustion (IC) engine - specifically the four-stroke engine common to most cars, commercial vehicles and some motorcycles (some motorbikes have a two-stroke engine).

The four stage sequence by which a reciprocating engine converts fuel (potential heat energy) into mechanical energy is more prosaically described in technical manuals as Induction, Compression, Power and Exhaust.

An equally accurate, but infinitely more decriptive, version is: Suck, Squeeze, Bang, Blow.

Suck: Induction stoke

Atomised fuel mixed with air is drawn into the cylinder by the lowering of the piston

Squeeze: Compression stroke

The piston rises again, compressing the vaporised fuel and air mix

Bang: Power stroke

The compressed fuel/air mix is ignited, the resulting explosion driving the piston back down

Blow: Exhaust stroke

The piston lifts once more, expelling the 'exhausted' gases into the exhaust manifold and along the exhaust

Because each piston is offset 180 degrees from the one next to it, as one piston goes down, the one beside it is forced up, and so constantly repeating the cycle - as long as there is fuel and spark, of course!

Franklin D Type engine exterior and sect

A litle history...

The theoretical concept of a four-cycle or four-stroke IC engine was patented by Alphonse Eugène Beau de Rochas in January 1862.

Other inventors such as Christian Reithmann, Eugenio Barsanti and Felice Matteucci also patented four-stroke IC engines and engine concepts.

It took inventors such as Jean J. Lenoir and Nikolaus A. Otto to build practical working IC units. The Otto version (built as a stationary engine running on coal-gas) was later used in a adpated form as an automotive engine.

Franklin Type D. Image courtesy of the New York Public Library Digital Collections

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