lewbloms

HELP!

I am making an airplane that will use a 911 engine. I'm designing the fuselage right now and need to know how much room to allow for the engine. The engine (any suggestions as to a good candidate?) will be one of the last things I buy because of the cost, but I need dimensions to work to now. None of the books or literature I've found have been any help on this.

At the very least I need the height, width and depth of a box the engine would fit in, as well as the height, width and depth of a box that would contain the transaxle.

You might ask what I need a transaxle for in an airplane. Well, for driving it down the road, obviously.

Seriously, I have figured out a way to collapse the wings into about 1/4 their chord and fold them along side the fuselage, making a 7' driving width and a 27' wingspan possible.

This one will be a two place, to keep the weight down. I will be entering it in the NASA General Aviation Technology Challenge ( see www.cafefoundation.org) in 2010 or 2011.

But I need dimensions now, as I'm designing the fuselage and space frame. The box dimensions would be adequate, but a scale 3 view drawing with dimensions would be ideal.

Does anyone out there know where I might find such a drawing?


lewbloms

old man neri

They have been making 911s for quite a while now with the engines progressively increasing in size. Some are naturally aspirated and some are not.

Do you want a water cooled engine or an air cooled engine.

And why don't you get a normal purpose built airplane engine?

ked

Porsche designed & certified a variant of the 911 motor in '81-'83, called it the PFM 3200. It was installed in a Cessna 182 and a few years later, in some Mooneys. The project came & went with Peter Schutz (then-Chairman). You might research Schutz, contact the museum in Stuttgart, & check the Mooney community.

lewbloms

My airplane will be roadable. Highway drive will be conventional rear wheel drive.

I chose the route of using the 911 engine/transaxle package primarily because it will be easier to adapt it to drive a propeller than to adapt an aircraft engine to drive the wheels. I am aware of the PFM 3200, but prefer the automotive 911 for the above reason.

The 911 engine is ideal because it is air cooled and has high power density. I realize it has grown in size over the years, which is why I'm open to suggestions as to what vintage to use. I need about 250 horsepower and fuel injection. Turbo would be nice, but not essential.

I would also like dual spark plugs. I know this is available on some racing engines, so it probably can be done after market. Dual plugs will enable me to make it dual ignition; a nice feature on an airplane.

Thanks for your interest guys!

jakeflyer

I have read about at least 2 car/aircraft in the aircraft history books. The EAA (Expermental Aircraft Assoc) can tell you where to find the info and they are the leaders in using engines other than certified engines. EAA has a pretty good history base of these engines and what has worked and costs. They tend to be thrifty, and safe. The thrust bearing on the 911 is designed for rotation and not heavy front and back loads that a prop produces. The engine/transaxle package is pretty heavy for flight. The transaxle is a 5 speed designed for over 100 mph speeds and tough enough for track use. It may be overkill and over weight.

I would first join the EAA and go to at least 2 meetings (to get the drift of the people) and then start learning what they have done and contact the members that are of interest to you. If you are well informed they will help you. If you appear tohave not done your research, you will get less help.

Amber Gramps

lewbloms, Are you by chance in Las Vegas?

ked

I would speculate that starting w/ the PFM3200 (itself derived from the road 3.2 motor) & "back-moding" a transaxle for road application would be better than starting from scratch - a lot of the critical & unique effort was performed - twin plug, etc. One could increase displacement to 3.4 or 3.5 w/o making external dimensional changes - unless of course you need or want a turbo - which you might, considering the eventual weight of the total pkg (or your targeted perf envelope). I would also research the lightest transaxles ever devised for 4 & 6 cyl Porsches & FV - maybe even a VW unit could be considered, trading strength for lightness / smallness (drive it on Earth in the "valet" mode...). good luck!

CarreraX

As much as I hate to say it......have you considered a Subaru? you can get a 300hp turbo STI motor fairly cheap and the transaxle is made for drive axles out the sides and an output in the back for maybe a propeller. Just a thought.