Headless engine

A headless engine or fixed-head engine^[1] is an engine where the end of the cylinder is cast as one piece with the cylinder and crankcase.^[2] The most well known headless engines are the Fairbanks-Morse Z and the Witte Headless hit-and-miss engine.^[3]

In the 21st century, light-duty consumer-grade Honda GC-family small engines use a use such a design, termed 'uniblock' by Honda.^[4] One reason for this, apart from cost, is to produce an overall lower engine height. Being an air-cooled OHC design, this is possible thanks to current aluminum casting techniques and lack of complex hollow spaces for liquid cooling. The valves are vertical, so as to permit assembly in this confined space. On the other hand, performing basic repairs becomes so time-consuming that the engine can be considered disposable.

See also

• Monobloc engine

An advertisement for a headless hit-and-miss engine

References

1. Goodsell, Don (2016-06-27). Dictionary of Automotive Engineering. Butterworth-Heinemann. ISBN 978-1-4831-0496-6.
2. "Fairbanks Morse headless engine 1917". www.practicalmachinist.com. 4 July 2013.
3. "Headless Witte Engines". www.oldengine.org. Archived from the original on 2020-02-25. Retrieved 2019-11-22.
4. "Honda General Purpose Engines: GC Series - Single Cylinder". Archived from the original on 2010-11-27. Includes sectioned drawings