Rapp 200 hp
| Industry | Aerospace |
|---|---|
| Founded | 1910s |
| Products | Aircraft engines |
The Rapp 200 hp was a water-cooled V-8 aircraft engine with a 90° configuration, produced by Rapp Motorenwerke.
Design and development
The Rapp 200 hp V-8 emerged around 1915 as an evolution of the earlier four-cylinder Rapp 100 hp model.[1] This powerplant featured eight cylinders arranged in two banks of four, each maintaining the identical bore and stroke dimensions of 140 mm × 160 mm (5.51 in × 6.30 in) originally used in the Rapp 100 hp.[2][3] It was reported to deliver approximately 200–205 hp (149–153 kW) at 1,350 rpm and had a weight in the range of 300–315 kg (661–694 lb).[2][3][4][5]
The architecture of the cylinders and valve mechanism closely followed that of the Rapp 100 hp four-cylinder engine.[3][1] Cylinders within each bank were paired, consisting of two separate forged steel liners screwed into a cast steel cylinder head shared by each pair. These heads incorporated integral cooling jackets and were cast in pairs before undergoing machining.[3]
Valve seats were manufactured as individual components, with exhaust valve seats featuring water cooling, and were screwed into the cylinder heads to allow straightforward removal during maintenance.[3][1] Each cylinder pair’s two intake valves and two exhaust valves were each actuated by a single pivoting leaf spring pressing them into their seats. The intake valves faced inward toward the Vee angle, while the exhaust valves were oriented outward.
Both intake and exhaust valves for each cylinder operated sequentially from a solitary cam lobe on an overhead camshaft through roller tappets and rocker arms.[3][6] The camshaft on each bank was driven by a vertical timing shaft equipped with bevel gears positioned between the pairs of cylinders. Two magnetos were also driven from this vertical shaft and located centrally between the cylinder banks.[3][1]
The crankcase was constructed from aluminum in two halves, split along the centerline into upper and lower sections. Its design mirrored that used for both the Rapp 100 hp four-cylinder and the six-cylinder Rapp Rp III (150 hp) engines. The crankshaft received support from main journals housed in the upper crankcase half.[7] Lubrication was provided by a gear pump mounted at the lowest point of the engine,[3] which supplied oil from two cylindrical reservoirs positioned front and rear beneath the crankcase to the crankshaft’s main journals.
Separate geared water pumps were installed on each side of the crankcase to circulate coolant individually for each cylinder bank.[3][1]
Fuel delivery was managed by two Zenith-type carburettors,[7] each serving one bank of four cylinders independently. Various configurations were tested regarding carburettor placement: some engines featured carburettors mounted at the rear end,[3] while others positioned them between the cylinder banks.[1] Additionally, intake air could be preheated by routing it through pipes exposed to exhaust heat before entering the carburettors.[3]
Rapp 300 hp V-12
This engine configuration was also adapted into a 60° V-12 layout.[8] The Rapp 300 hp V-12 reportedly delivered approximately 300 hp (224 kW) at around 1,350 to 1,400 rpm, with a weight close to 470–474 kg (1,036–1,045 lb).[3][5] Various versions seem to have been tested featuring exhausts oriented both outward[9] and inward[8] facing arrangements, the latter often shown equipped with Pallas carburettors.
Variants
- 200 hp Rapp V-8[3]
- Circa 1915, outputting 200 hp (149 kW) at 1,350–1,400 rpm, featuring a bore and stroke of 140 mm × 160 mm (5.5 in × 6.3 in)[2][4][5]
- 300 hp Rapp V-12[3]
- Circa 1915, delivering 300 hp (224 kW) at 1,350–1,400 rpm with bore and stroke dimensions of 140 mm × 160 mm (5.5 in × 6.3 in)[5]
Specifications (200 hp Rapp V-8)
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 BMW Group Archives. Achtzylinder Rapp - Flugmotor, 200 PS (photo)
- ↑ 2.0 2.1 2.2 Angle. 1921. p. 402
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 Huth. 1920. p. 145-147, 130-134
- ↑ 4.0 4.1 Eyb. 1918. p. 125
- ↑ 5.0 5.1 5.2 5.3 Klamroth. 1916. p. 235
- ↑ cf. Der Motorwagen. 20 January 1918. pp. 14-15
- ↑ 7.0 7.1 Schwager. 1918. pp. 114–115
- ↑ 8.0 8.1 BMW Group Archives. Zwölfzylinder Rapp - Flugmotor, 300 PS.
- ↑ BMW Group Archives. Flugmotorenprüfstände der Rapp Motoren-Werke (photo). 60° V-12 in the middle, note the outward-facing exhausts
Bibliography
- Angle, Glenn Dale (1921). Airplane Engine Encyclopedia: An Alphabetically Arranged Compilation Of All Available Data On The World's Airplane Engines. Otterbein Press. pp. 402-404. OL 23525261M.
- Eyb, Robert (1918). Fliegerhandbuch (in Deutsch) (3rd ed.). Berlin: R.C. Schmidt & Co. OCLC 9500053.
- Huth, Fritz (1920). Motoren für Flugzeuge und Luftschiffe (in Deutsch) (3rd ed.). Berlin: R. C. Schmidt & co. OCLC 2116726.
- Klamroth, Gerhard (1916). Schiffsmaschinenkunde mit besonderer Berücksichtigung der Dampfturbinen und Ölmotoren (in Deutsch). Berlin: E.S. Mittler und Sohn.
- "Zur Konstruktion der Steuerung". Der Motorwagen (in Deutsch). 21 (2). Berlin: Krayn: 13–16. 20 January 1918.
- Rapp. "Achtzylinder Rapp - Flugmotor, 200 PS". BMW Group archives. BMW Group.
- Rapp. "Zwölfzylinder Rapp - Flugmotor, 300 PS". BMW Group archives. BMW Group.
- Rapp. "Flugmotorenprüfstände der Rapp Motoren-Werke". BMW Group archives. BMW Group.
External links
- Test bench images displaying the Rapp 200 hp V-8, 300 hp V-12, and 125/145 hp Rp II V-8 engines (arranged left to right), highlighting the variation in propeller sizes: FF-3380-44 (BMW Group archives)
- Photographs of the Rapp 300 hp V-12 engine featuring inward-oriented exhausts and equipped with Pallas carburettors: FF-3380-41 FF-3380-42 (BMW Group archives)