Editing Ford Sigma engine (section)

==Introduction and production==
As with the [[Ford SHO V6 engine|SHO V6 engine]], development of the Zetec-S was a collaborative effort between [[Ford Motor Company|Ford]], [[Mazda]] and [[Yamaha Motor Corporation|Yamaha]].<ref name="lesoir">{{cite web |url=https://www.lesoir.be/art/un-moteur-zetec-leger-original-au-bruit-raffine_t-19960316-Z0AUU7.html |title=Un moteur Zetec léger, original et au bruit raffiné | trans-title = A light Zetec engine, original and with a refined sound | language = fr | last =Binon | first = Pascal |date=March 16, 1996 |archiveurl=https://web.archive.org/web/20220315195925/https://www.lesoir.be/art/un-moteur-zetec-leger-original-au-bruit-raffine_t-19960316-Z0AUU7.html |archivedate=2022-03-15 |url-status=live |work=[[Le Soir]]}}</ref><ref name="autonews">{{cite news |url=https://europe.autonews.com/article/19970707/ANE/707070802/yamaha-coats-cylinders-for-ford-puma |title=Yamaha coats cylinders for Ford Puma | last =Lewin | first = Tony |date=July 7, 1997 |archiveurl=https://web.archive.org/web/20190317232401/https://europe.autonews.com/article/19970707/ANE/707070802/yamaha-coats-cylinders-for-ford-puma |archivedate=2019-03-17 |url-status=live |newspaper=[[Automotive News]]}}</ref> The engine's sound profile was refined in Ford's acoustics center in [[Cologne|Cologne-Merkenich]], [[Germany]].<ref name="lesoir" /> Production of the Zetec-SE was carried out in the Ford Valencia Engine Plant, with Yamaha building the 1.7&nbsp;L engine blocks in Japan.<ref name="lesoir" /><ref name="autonews" />

When the Zetec-SE debuted in 1995, it included many firsts, including a plastic inlet manifold, a "ladder" style [[main bearing]] and [[crankcase]] assembly, and big-end bearing caps which are forged in one piece and subsequently split. It also incorporates [[powder metal]] [[connecting rod]]s, which were quite exotic at the time. This feature makes the engine more challenging to rebuild at the end of its working life, since it is not possible to re-machine the bearing ladder as is done with a conventional cylinder block — the entire assembly has to be renewed. Despite this, engine tuners have found novel ways to increase the power of the unit through use of different valves and increasing the compression ratio of the engine through skimming of the cylinder head.

The engine first appeared in the [[Ford Fiesta (fourth generation)|Mk4 Ford Fiesta]] and the virtually identical [[Mazda 121]] in {{cvt|1242|cc|L|1|order=flip}} capacity, with {{cvt|1388|cc|L|1|order=flip}}, {{convert|1596|cc|L|1|order=flip}} and {{cvt|1679|cc|L|1|order=flip}} derivatives coming later.