A '''headless engine''' or '''fixed-head engine'''<ref>{{Cite book |last=Goodsell |first=Don |url=https://books.google.com/books?id=DX-8DAAAQBAJ&dq=%22fixed+head+engine%22&pg=PA60 |title=Dictionary of Automotive Engineering |date=2016-06-27 |publisher=Butterworth-Heinemann |isbn=978-1-4831-0496-6 |language=en}}</ref> is an engine where the end of the cylinder is cast as one piece with the cylinder and crankcase.<ref>{{Cite web|url=https://www.practicalmachinist.com/vb/antique-machinery-and-history/fairbanks-morse-headless-engine-1917-a-268395/|title=Fairbanks Morse headless engine 1917.|website=www.practicalmachinist.com|date=4 July 2013 }}</ref> The most well known headless engines are the Fairbanks-Morse Z and the Witte Headless hit-and-miss engine.<ref>{{Cite web|url=http://www.oldengine.org/members/cmsgma/2000show/headless.html|title=Headless Witte Engines|website=www.oldengine.org|access-date=2019-11-22|archive-date=2020-02-25|archive-url=https://web.archive.org/web/20200225115548/http://www.oldengine.org/members/cmsgma/2000show/headless.html|url-status=dead}}</ref>

In the 21st century, light-duty consumer-grade Honda GC-family small engines use a use such a design, termed 'uniblock' by Honda.<ref>{{cite web |title = Honda General Purpose Engines: GC Series - Single Cylinder |url = http://www.perr.com/honda.html |url-status = dead |archive-url = https://web.archive.org/web/20101127185645/http://perr.com/honda.html |archive-date = 2010-11-27 }} Includes sectioned drawings</ref> 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

[[File:Z Headless ad.png|thumb|200px|An advertisement for a headless hit-and-miss engine ]]

==References== {{reflist}}

Category:Engines Category:Engine technology Category:Piston engine configurations

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