<!-- This article is a part of Wikipedia:WikiProject Aircraft. Please see Wikipedia:WikiProject Aircraft/page content for recommended layout. --> {{infobox aero engine |name=Rapp 200 hp |image=Rapp 200 hp aircraft engine, side view.jpg |caption=Rapp 200 hp V-8 aircraft engine, side view |engine_type=Inline piston engine |national_origin=Germany |manufacturer=Rapp Motorenwerke |first_run={{circa|1915}} |major_applications= |number_built= |developed_from=Rapp 100 hp |developed_into= |variants_with_their_own_articles= }}
The '''Rapp 200 hp''' was a water-cooled 90° V-8 aircraft engine built by Rapp Motorenwerke.
==Design and development== The Rapp 200 hp V-8 engine design was derived from the earlier four-cylinder Rapp 100 hp design approximately around 1915.<ref name="BMW-Rapp200">''BMW Group Archives''. Achtzylinder Rapp - Flugmotor, 200 PS (photo)</ref> It had eight cylinders with the same bore and stroke of {{cvt|140|x|160|mm|in|2}} as the Rapp 100 hp, arranged in two rows of four.<ref name="Angle1921">Angle. 1921. p. 402</ref><ref name="Huth1920">Huth. 1920. p. 145-147, 130-134</ref> The engine was said to produce about {{cvt|200|-|205|hp|0}} at 1,350 rpm, while weighing about {{cvt|300|-|315|kg|0}}.<ref name="Angle1921"/><ref name="Huth1920" /><ref name="Eyb1918">Eyb. 1918. p. 125</ref><ref name="Klamroth1916">Klamroth. 1916. p. 235</ref>
The design of the cylinders and the valvetrain also reflected the design of the Rapp 100 hp four-cylinder.<ref name="Huth1920"/><ref name="BMW-Rapp200"/> The cylinders of each cylinder row were again arranged in pairs composed of two separate forged steel cylinder liners screwed into the pairwise cast cylinder heads. The cylinder heads had integral cooling jackets and were cast from steel in pairs and then machined.<ref name="Huth1920"/>
The valve seats, with the exhaust valve seats being water-cooled, were separately built parts which were screwed into the cylinder heads and could be easily removed for maintenance work.<ref name="Huth1920"/><ref name="BMW-Rapp200"/> Both inlet valves of the cylinder pair, and likewise so both exhaust valves on the other side, were pressed into their seat by a single pivoted leaf spring. The intake was oriented to inner side of the Vee and the exhaust was oriented to the outer side.
Each cylinder's exhaust and inlet valves were actuated successively from a single cam lobe on the overhead camshaft via roller tappets and rocker arms.<ref name="Huth1920"/><ref>cf. ''Der Motorwagen''. 20 January 1918. pp. 14-15</ref> The camshaft of each cylinder row was driven via a vertical timing shaft and bevel gears between the two cylinder pairs. Two magnetos were also driven from the vertical timing shaft and were located between the two cylinder rows.<ref name="Huth1920"/><ref name="BMW-Rapp200"/>
The crankcase was cast from aluminum in two pieces, parted at the center line in an upper and a lower part. It was designed in the same manner as the Rapp 100 hp four cylinder and the 150 hp Rapp Rp III six-cylinder engines. The crankshaft was supported by the main journals in the upper part of the crankcase.<ref name="Schwager1918">Schwager. 1918. pp. 114–115</ref> Lubrication was done by a gear pump which was mounted on the lowest point of the engine.<ref name="Huth1920"/> The gear pump fed the oil from two cylindrical oil reservoirs, mounted front and aft below the engine crankcase, to the main journals of the crankshaft. In order to circulate the engine coolant separate geared water pumps were installed on the respective side of the crankcase for each cylinder row.<ref name="Huth1920"/><ref name="BMW-Rapp200"/>
The engine had two Zenith-type<ref name="Schwager1918"/> carburettors, of which each fed one row of four cylinders separately. It appears that different arrangements for the two carburettors have been tried. Some of the engines had the carburettors located at the back end of the engines,<ref name="Huth1920"/> while others had them located between the cylinder rows.<ref name="BMW-Rapp200"/> Also preheated air could be provided to the carburettors via intake air pipes routed through the exhaust.<ref name="Huth1920"/>
===Rapp 300 hp V-12=== The same engine design was also implemented as 60° V-12 engine.<ref name="BMW-Rapp300">''BMW Group Archives''. Zwölfzylinder Rapp - Flugmotor, 300 PS.</ref> The Rapp 300 hp V-12 was said to produce around {{cvt|300|hp|0}} at about 1,350-1,400 rpm, while weighing about {{cvt|470|-|474|kg|0}}.<ref name="Huth1920" /><ref name="Klamroth1916"/> It appears that different variants with outward-facing<ref name="BMW-RappTestbench">''BMW Group Archives''. Flugmotorenprüfstände der Rapp Motoren-Werke (photo). 60° V-12 in the middle, note the outward-facing exhausts</ref> and inward-facing<ref name="BMW-Rapp300"/> exhausts have been tried, the latter variant also depicted with Pallas carburettors.
==Variants== ;200 hp Rapp V-8<ref name="Huth1920"/> :{{circa|1915}}, {{cvt|200|hp|0}}, 1,350–1,400 rpm, {{cvt|140|x|160|mm}} bore and stroke<ref name="Angle1921"/><ref name="Eyb1918"/><ref name="Klamroth1916"/> ;300 hp Rapp V-12<ref name="Huth1920"/> :{{circa|1915}}, {{cvt|300|hp|0}}, 1,350–1,400 rpm, {{cvt|140|x|160|mm}} bore and stroke<ref name="Klamroth1916"/>
==Specifications (200 hp Rapp V-8)== {{pistonspecs| <!-- If you do not understand how to use this template, please ask at Wikipedia talk:WikiProject Aircraft --> <!-- Please include units where appropriate (main comes first, alt in parentheses). If data are missing, leave the parameter blank (do not delete it). For additional lines, end your alt units with )</li> and start a new, fully formatted line with <li> --> |ref=''Angle''<ref name="Angle1921"/> |type=eight-cylinder, water-cooled V-8 piston engine |bore={{cvt|140|mm|in|2}} |stroke={{cvt|160|mm|in|2}} |displacement={{cvt|19.7|L|cuin|0}} |length= |diameter. |width= |height= |weight={{cvt|300|kg|0}} |valvetrain=two single overhead camshaft-actuated valves per cylinder |supercharger= |turbocharger= |fuelsystem= |fueltype= |oilsystem= |coolingsystem=Water-cooled |power={{cvt|200|hp|0}} at 1,350 rpm |specpower= |compression= |fuelcon= |specfuelcon= |oilcon= |power/weight= |designer=Karl Rapp |reduction_gear=Direct-drive |general_other= |components_other= |performance_other= }}
==See also== {{aircontent <!-- other related articles that have not already linked: --> |see also=
<!-- designs which were developed into or from this aircraft: --> |related= *Rapp 100 hp *Rapp 125/145 hp *Rapp Rp III
<!-- aircraft that are of similar role, era, and capability this design: --> |similar aircraft=
<!-- relevant lists that this aircraft appears in: --> |lists= *List of aircraft engines <!-- For aircraft engine articles. Engines that are of similar to this design: --> |similar engines=
<!-- See WP:Air/PC for more explanation of these fields. --> }}
==References== {{reflist}}
===Bibliography===
*{{cite book |title=Airplane Engine Encyclopedia: An Alphabetically Arranged Compilation Of All Available Data On The World's Airplane Engines |last=Angle |first=Glenn Dale |year=1921 |publisher=Otterbein Press |pages=[https://archive.org/details/AirplaneEngineEncyclopedia/page/n417/mode/2up 402-404] |url=https://archive.org/details/AirplaneEngineEncyclopedia |ol=23525261M }}
*{{cite book |last=Eyb |first=Robert |title=Fliegerhandbuch |publisher=R.C. Schmidt & Co. |location=Berlin |edition=3rd |year=1918 |language=de |url=https://catalog.hathitrust.org/Record/005346784 |oclc=9500053 }}
*{{cite book | last=Huth | first=Fritz | title=Motoren für Flugzeuge und Luftschiffe | edition=3rd | publisher=R. C. Schmidt & co. | location=Berlin | year=1920 | language=de | url=https://catalog.hathitrust.org/Record/101817726 | oclc=2116726 }}
*{{cite book |last=Klamroth |first=Gerhard |title=Schiffsmaschinenkunde mit besonderer Berücksichtigung der Dampfturbinen und Ölmotoren |publisher=E.S. Mittler und Sohn |location=Berlin |date=1916 |language=de |url=https://books.google.com/books?id=URxLAAAAMAAJ }}
*{{cite journal |author=<!--Staff writer(s); no by-line.--> |title=Zur Konstruktion der Steuerung |journal=Der Motorwagen |date=20 January 1918 |volume=21 |issue=2 |pages=13–16 |publisher=Krayn |location=Berlin |language=de |url=https://catalog.hathitrust.org/Record/000638153 }}
*{{cite web |url=https://www.bmw-grouparchives.com/research/detail/index.xhtml?id=1093627 |title=Achtzylinder Rapp - Flugmotor, 200 PS |author=Rapp |date= |website=BMW Group archives |publisher=BMW Group |access-date=31 December 2020 |quote=200 PS 8 cyl. Rappmotor 1915 }}
*{{cite web |url=https://www.bmw-grouparchives.com/research/detail/index.xhtml?id=1093749 |title=Zwölfzylinder Rapp - Flugmotor, 300 PS |author=Rapp |date= |website=BMW Group archives |publisher=BMW Group |access-date=31 December 2020 |quote= }}
*{{cite web |url=https://www.bmw-grouparchives.com/research/detail/index.xhtml?id=1093800 |title=Flugmotorenprüfstände der Rapp Motoren-Werke |author=Rapp |date= |website=BMW Group archives |publisher=BMW Group |access-date=31 December 2020 |quote= }}
==External links== {{Commons category}} *Rapp 200 hp V-8, 300 hp V-12 and 125/145 hp Rp II V-8 engines (from left to right) at the test bench, also note the different size propellers: [https://www.bmw-grouparchives.com/research/detail/index.xhtml?id=1093800 FF-3380-44] ([https://bmw-grouparchives.com BMW Group archives]) *Rapp 300 hp V-12 engine, version with inward-facing exhausts and Pallas carburettors: [https://www.bmw-grouparchives.com/research/detail/index.xhtml?id=1093725 FF-3380-41] [https://www.bmw-grouparchives.com/research/detail/index.xhtml?id=1093749 FF-3380-42] ([https://bmw-grouparchives.com BMW Group archives])
{{Rapp aeroengines}}
Category:1910s aircraft piston engines Category:Rapp aircraft engines Category:V8 engines Category:Liquid-cooled aircraft piston engines