Maybach VL I
| {{Infobox aircraft begin
| name = VL I | image = File:Bundesarchiv Bild 102-07783, Maybach-Zeppelin-Motor.jpg | caption = Maybach VL II, a similar engine }} {{Infobox aircraft engine | type = V-12 liquid-cooled 4-stroke piston engine (Otto) | national origin = Germany | manufacturer = Maybach | designer = | first run = | major applications = USS Los Angeles (ZR-3) / LZ 126 | status = | produced = 1924 | number built = at least five | program cost = | unit cost = | developed from = Maybach Mb IVa | variants with their own articles = | developed into = Maybach VL II }} |
The Maybach VL I was an Otto cycle V-12 engine, made from 1924 in Germany. The airship LZ 126 was powered by five VL I engines which emphasised reliability and low fuel consumption.
Technical description
The VL I was a V-12 liquid-cooled four-stroke Otto cycle engine, with individual grey cast iron cylinders, with a cylinder bore of {{convert|140|mm|abbr=on}}, piston stroke of {{convert|180|mm|abbr=on}}, and displacement of {{convert|33.255|L|cuin|abbr=on}}. The crankshaft was supported in roller-bearings and was fitted with a vibration damper for smooth operation. The overhead valves, one large inlet valve and two smaller outlet valves per cylinder, were operated by a camshaft running between the cylinder banks, operating the valves with tappets, pushrods and rocker arms.
The majority of the ancillary equipment was run by the camshaft to reduce vibration. Fuel was mixed with air by two fireproof Maybach carburetors per cylinder bank, with two header tanks above the carburetors providing fuel. Compressed air was used to start the engine; two tanks with a volume of {{convert|25|m3|cuft|abbr=on}} at {{convert|29|bar|psi|abbr=on}} supplied compressed air directly to each cylinder to start the engine.
To change the direction of rotation of the crankshaft, the camshaft, with lobes for normal or reverse operation, could be moved by compressed air to change over the cams in use. This mechanism, used to decelerate and halt aircraft, was operated by an engineer, accommodated in the engine nacelles, with levers.
Specifications
{{pistonspecs|
|type=V-12 4-stroke liquid-cooled piston engine (Otto)
|bore={{convert|140|mm|abbr=on}}
|stroke={{convert|180|mm|abbr=on}}
|displacement={{convert|33,255|cm3|cuin|abbr=on}}
|length=
|diameter=
|width=
|height=
|weight=
|valvetrain=pushrod operated overhead valves: 1 × inlet, 2 × exhaust with reversible rotation cams
|supercharger=
|turbocharger=
|fuelsystem=2 × carburetors per cylinder bank
|oilsystem=pressure feed
|coolingsystem=liquid-cooled
|power={{convert|420|PS|kW|1|abbr=on}}
|specpower=
|compression=5.8:1
|fuelcon=
|specfuelcon= 258.3 g/kWh
|oilcon=
|power/weight=
|designer=
|reduction_gear=
|general_other=
|components_other=
|performance_other=
}}