Lancia Flat-4 engine
{{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-4
|valvetrain=Pushrod or Overhead camshaft
|block=Light alloy
|head=Aluminum
|fueltype=Petrol
|fuelsystem={{Unbulleted list|Twin-choke Weber carburetor|Fuel injection}}
|coolingsystem=Water-cooled
|displacement={{Unbulleted list|{{convert|1488|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1490|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1500|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1727|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1800|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1816|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1991|cc|L cuin|1|order=flip|abbr=on}}|{{convert|1999|cc|L cuin|1|order=flip|abbr=on}}|{{convert|2484|cc|L cuin|1|order=flip|abbr=on}}}}
|bore={{Unbulleted list|{{convert|77|mm|in|2|abbr=on}}|{{convert|80|mm|in|2|abbr=on}}|{{convert|82|mm|in|2|abbr=on}}|{{convert|88|mm|in|2|abbr=on}}|{{convert|89|mm|in|abbr=on}}}}
|stroke={{Unbulleted list|{{convert|71|mm|in|abbr=on}}|{{convert|74|mm|in|2|abbr=on}}|{{convert|80|mm|in|2|abbr=on}}|{{convert|85|mm|in|2|abbr=on}}}}
|predecessor=Lancia V4 engine
|power={{convert|92-140|bhp|kW PS|0|abbr=on}}
|torque={{convert|172-208|Nm|lbft|0|abbr=on}}
|sp=uk
}}
The Lancia Flat-4 engine is an aluminum, pushrod, and later overhead camshaft, flat-four (boxer) engine made by Lancia, initially for the Flavia, from 1960 through 1984. Though it was designed as a pushrod engine, it was advanced for the time.{{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 {{convert|92|bhp|kW PS|0|abbr=on}}, was far beyond VW's modest output in those days, even allowing for the displacement discrepancy.}} The pushrod version of the Lancia boxer was only ever used in the 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 Gamma.
Pushrod
=1500=
The original version was the {{convert|1500|cc|L cuin|1|order=flip|abbr=on}} introduced in 1960; it used an {{convert|82x71|mm|in|2|abbr=on}} bore and stroke. It was revised on 1963 with a smaller {{convert|80|mm|in|2|abbr=on}} bore and a longer {{convert|74|mm|in|2|abbr=on}} stroke, thus displacing {{convert|1488|cc|L cuin|1|order=flip|abbr=on}}. A final version was introduced in 1967 with an even longer {{convert|80|mm|in|2|abbr=on}} stroke coupled with a {{convert|77|mm|in|2|abbr=on}} bore, giving a displacement of {{convert|1490|cc|L cuin|1|order=flip|abbr=on}}. Production ceased in 1970.
=1800=
The first 1800 was a {{Convert|1727|cc|L cuin|1|order=flip|abbr=on}} introduced in 1962. It used an {{Convert|88x71|mm|in|2|abbr=on}} bore and stroke. One year later it was replaced by a true {{Convert|1800|cc|L cuin|1|order=flip|abbr=on}} engine thanks to a longer {{Convert|74|mm|in|2|abbr=on}} stroke. In 1967 appeared the {{Convert|1816|cc|L cuin|1|order=flip|abbr=on}} version using an {{Convert|85x80|mm|in|2|abbr=on}} bore and stroke.
=2000=
The {{convert|1991|cc|L cuin|1|order=flip|abbr=on}} 2000 version was the ultimate Flavia engine. Bore and stroke was {{Convert|89x80|mm|in|2|abbr=on}} for a good oversquare ratio. In 1971, the 2.0 L produced {{convert|115|bhp|kW PS|0|abbr=on}},{{cn|date=August 2021}} and in the HF Coupé in 1972 it produced {{convert|125|bhp|kW PS|0|abbr=on}}. 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 flat-four engine.]]
=2000=
Replacing the 2.0 L pushrod engine used in the Flavia, the new {{Convert|1999|cc|L cuin|1|order=flip|abbr=on}} OHC engine produced {{convert|120|bhp|kW PS|0|abbr=on}} at 5500 rpmDaily Express Guide to World Cars 1980, page 37 and {{convert|172|Nm|lbft|0|abbr=on}} of torque at 3500 rpm.
=2500=
The {{convert|2484|cc|L cuin|1|order=flip|abbr=on}} engine was initially available with twin-choke Weber carburetors, but in the last few years of production it was equipped with fuel injection. In both forms, it produced {{convert|140|bhp|kW PS|0|abbr=on}} at 5400 rpm and {{convert|208|Nm|lbft|0|abbr=on}} torque at 3000 rpm.Car Catalogue International 1983, page 53
References
{{Commons category|Lancia Flat-4 engine}}
{{reflist}}
{{DEFAULTSORT:Lancia Flat-4 Engine}}
{{Lancia}}