{{Infobox automobile engine |name=Flat-4 engine |image=Lancia Flavia Flat four (Boxer) engine (26097832230).jpg |caption=Boxer engine installed in a [[Lancia Flavia]] |production=1960-1984 |configuration=[[Naturally aspirated]] [[Flat-four engine|Flat-4]] |valvetrain=[[Pushrod]] or [[Overhead camshaft]] |block=Light alloy |head=Aluminum |fueltype=[[Petrol engine|Petrol]] |fuelsystem={{ubl|Twin-[[Choke valve|choke]] [[Weber carburetor]]|[[Fuel injection]]}} |coolingsystem=[[Radiator (engine cooling)|Water-cooled]] |displacement={{ubl|{{cvt|1488|cc|L cc cuin|1|order=out}}|{{cvt|1490|cc|L cc cuin|1|order=out}}|{{cvt|1500|cc|L cc cuin|1|order=out}}|{{cvt|1727|cc|L cc cuin|1|order=out}}|{{cvt|1800|cc|L cc cuin|1|order=out}}|{{cvt|1816|cc|L cc cuin|1|order=out}}|{{cvt|1991|cc|L cc cuin|1|order=out}}|{{cvt|1999|cc|L cc cuin|1|order=out}}|{{cvt|2484|cc|L cc cuin|1|order=out}}}} |bore={{ubl|{{cvt|77|mm|in|2}}|{{cvt|80|mm|in|2}}|{{cvt|82|mm|in|2}}|{{cvt|88|mm|in|2}}|{{cvt|89|mm|in}}}} |stroke={{ubl|{{cvt|71|mm|in}}|{{cvt|74|mm|in|2}}|{{cvt|80|mm|in|2}}|{{cvt|85|mm|in|2}}}} |predecessor=[[Lancia V4 engine]] |power={{cvt|92-140|bhp|kW PS|0}} |torque={{cvt|172-208|Nm|lbft|0}} }} The '''Lancia Flat-4 engine''' is an aluminum, [[pushrod engine|pushrod]], and later [[Overhead camshaft engine|overhead camshaft]], [[flat-four engine|flat-four (boxer) engine]] made by [[Lancia]], initially for the [[Lancia Flavia|Flavia]], from 1960 through 1984. Though it was designed as a pushrod engine, it was advanced for the time.<ref>{{cite web|last=Koch|first=Jeff|title=Lancia Flavia 1.8 Coupe vs. Alfa GTV 1750|url=http://www.hemmings.com/hsx/stories/2008/04/01/hmn_feature15.html|work=Hemmings Motor News|publisher=American City Business Journals|accessdate=28 December 2013|date=April 2008|quote=Lancia's four has its cylinders [[horizontally-opposed]], à la [[Porsche]] (or [[VW Beetle]] if you're uncharitable)--except it's water-cooled, hanging out over the nose, and driving the front wheels. Power, even at {{cvt|92|bhp|kW PS|0}}, was far beyond VW's modest output in those days, even allowing for the displacement discrepancy.}}</ref> The pushrod version of the Lancia boxer was only ever used in the [[Lancia Flavia|Flavia]], and its derivatives including the [[Lancia 2000]]. In 1976, a new [[overhead cam]] engine based on a similar layout was designed and brought into production in 2 and 2.5-litre displacements for the [[Lancia Gamma|Gamma]].
==Pushrod== [[File:Lancia Flavia convertibile engine, Lime Rock.jpg|thumb|left|Engine in a Lancia Flavia convertibile (by Vignale) at the 2014 Lime Rock Gathering of the Marques attached to the [[Concours d'Elegance]]]]
===1500=== The original version was the {{cvt|1500|cc|L cc cuin|1|order=out}} introduced in 1960; it used an {{cvt|82x71|mm|in|2}} bore and stroke. It was revised on 1963 with a smaller {{cvt|80|mm|in|2}} bore and a longer {{cvt|74|mm|in|2}} stroke, thus displacing {{cvt|1488|cc|L cc cuin|1|order=out}}. A final version was introduced in 1967 with an even longer {{cvt|80|mm|in|2}} stroke coupled with a {{cvt|77|mm|in|2}} bore, giving a displacement of {{cvt|1490|cc|L cc cuin|1|order=out}}. Production ceased in 1970.
===1800=== The first '''1800''' was a {{cvt|1727|cc|L cc cuin|1|order=out}} introduced in 1962. It used an {{cvt|88x71|mm|in|2}} bore and stroke. One year later it was replaced by a true {{cvt|1800|cc|L cc cuin|1|order=out}} engine thanks to a longer {{cvt|74|mm|in|2}} stroke. In 1967 appeared the {{cvt|1816|cc|L cc cuin|1|order=out}} version using an {{cvt|85x80|mm|in|2}} bore and stroke.
===2000=== The {{cvt|1991|cc|L cc cuin|1|order=out}} '''2000''' version was the ultimate Flavia engine. Bore and stroke was {{cvt|89x80|mm|in|2}} for a good [[oversquare]] ratio. In 1971, the 2.0 L produced {{cvt|115|bhp|kW PS|0}},{{cn|date=August 2021}} and in the HF [[Coupé]] in 1972 it produced {{cvt|125|bhp|kW PS|0}}. This engine was produced from 1968 through 1974.
==OHC== Lancia developed the large light-alloy [[overhead camshaft]] 2.0-litre and 2.5-litre flat-4 engines specifically for the [[Lancia Gamma]], rather than using Fiat derived engines as used in the Beta and Montecarlo and were in production between 1976 and 1984.
[[File:Lancia Gamma Engine.jpg|left|thumb|A [[Lancia Gamma]] flat-four engine.]]
===2000=== Replacing the 2.0 L pushrod engine used in the Flavia, the new {{cvt|1999|cc|L cc cuin|1|order=out}} OHC engine produced {{cvt|120|bhp|kW PS|0}} at 5500 rpm<ref>Daily Express Guide to World Cars 1980, page 37</ref> and {{cvt|172|Nm|lbft|0}} of torque at 3500 rpm.
===2500=== The {{cvt|2484|cc|L cc cuin|1|order=out}} engine was initially available with twin-[[Choke valve|choke]] [[Weber carburetor]]s, but in the last few years of production it was equipped with [[fuel injection]]. In both forms, it produced {{cvt|140|bhp|kW PS|0}} at 5400 rpm and {{cvt|208|Nm|lbft|0}} torque at 3000 rpm.<ref>[[Car Catalogue International]] 1983, page 53</ref>
==References== {{Commons category|Lancia Flat-4 engine}} {{reflist}}
{{DEFAULTSORT:Lancia Flat-4 Engine}} {{Lancia}}
[[Category:Lancia engines|Flat-4]] [[Category:Boxer engines]] [[Category:Gasoline engines by model]] [[Category:Four-cylinder engines]] [[Category:1960s automobile engines]]