Hand Pumps and Oil Pressure... How to Fly a WWI Plane?

[stephen]

Originally Posted by Greybeard

There's an important thing to specify: inline or rotary?

Indeed, only a rotary should require oil under pressure, an inline doesn't make sense: just a scavenging pump that sucks oil from carter and pumps it to camshaft should be required, all in a closed circuit, since dry carters I think still weren't used.

I'm no mechanic, but why would a rotary need oil pressure? Didn't the centrifugal force of the whirling engine bleed the oil from the inside of the engine into the cylinders, where it was discarded by flying into outer space (and the pilot's face) as it left? I thought rotaries had no true pressure system at all... the oil just literally sprayed from the inside of the engine and out through the cylinders?

[Ransom E. Olds]

Stephen: Pending the arrival in this thread of someone who actually knows why the gage has an off-on position, I'm going to suggest it was to make it possible to shut off the flow of oil to the instrument in case it (the gage itself) began leaking. Fuel and oil line breakages weren't uncommon in the Great War and I suspect the bourdon tube in the oil pressure gage might have been an additional weak point. Ransom

[Greybeard]

Stephen,

all what you're saying is right, but lack of an oil pressure system.

Oil must be brought by means of some device from its reservoir to engine carter; you could use an engine-driven mechanical pump, for instance, but it looks they preferred to pressurize it into its tank and then let it flow to engine pushed by this pressure.