BritishV8 Forum

General Category => Engine, Transmission, & Rear Axle assy. => Topic started by: danmas on September 30, 2010, 10:05:17 PM

Title: Upside down lubrication.
Post by: danmas on September 30, 2010, 10:05:17 PM
OK, I'm not as sharp as I should be. Not only do I miss the answer, I far too often miss the question. In the report on the 2008 V8 meet, there was a bit about a 215 aluminum V8 being used upside down in an airplane. http://www.britishv8.org/Articles/2008-Group-Outings.htm

Normally, oil is pumped through the engine and then it drains back to the sump for recirculation. In this case, the oil would drain back to the valve covers and the underside of the pistons.

I've seen airplanes fly upside down many times, but it never occured to me until now to question the oiling system operation when upside down.

How is that dealt with?
Title: Re: Upside down lubrication.
Post by: 7sand8s on October 01, 2010, 08:37:31 AM
They use an inverted oil system:
http://www.aircraftspruce.com/catalog/eppages/christen801.php
The fuel system is a header tank or flop tubes in the tanks for inverted flight.
Fuel injected engine.
Title: Re: Upside down lubrication.
Post by: flitner on October 05, 2010, 08:10:02 PM
The oil system pulls off of a specially designed upper pickup in the crankcase, working off of gravity in an upside down/inverted flight situation for an unlimited time,however the fuel sump in the airframe makes up for +- 60 seconds of inverted flight on a aerobatic manuever as per a 69 Citabria "Airbatic" spelled bakerds!
Title: Re: Upside down lubrication, with a girdle ?
Post by: roverman on October 31, 2010, 06:15:25 PM
I.E. "side oiler girdle' for Rover. Monoblock design as main caps and girdle are one piece. Main oil galley machined in girdle, feeds lateral ports to lower bearing halves. Initially thought was to have these lines feed nearly horizontal into bearing shells. Great for "swirl and wedge effect", but bad for feeding oil into crank oil holes,(to rods).Good compromise angle ? Since this is true "priority oiling", I suspect a reduced port size to lube cam bearings should be required. Mechanical roller lifters to be splash lubed. Rockers lubed by external lines to shafts.  Anyone? Thanks, roverman.
Title: Re: Upside down lubrication.
Post by: Wotland on November 01, 2010, 04:22:13 AM
Art, you need of this LOL :
(http://i20.servimg.com/u/f20/11/14/83/96/sump_g12.jpg) (http://www.servimg.com/image_preview.php?i=56&u=11148396)
Title: Re: Upside down lubrication.
Post by: roverman on November 01, 2010, 08:00:59 PM
Wotland, so pfunny ? The engine needs the girdle, so crank does'nt get "cranky"-get it ?