Our initial thought was to do Speed 400 sized (ie, 48" WS) airplanes. This is a good size for flying at 60 Acres. We would limit the motor size to that of  Speed 400 but not restrict it to an actual S-400 DC motor.

We would use SAM Electric Rules as a starting point. 

Airplanes must be of a prototype that flew before 1943.

A wing loading of 8oz/sqft is required.

Any motor would be allowed as long as it is the size of a Speed 400 or smaller.

We will use the SAM 2008 Electric Rules.

We will be having a meeting to refine these rules.

SAM Electric Information (Slow loading document)

MotoCalc

MotoCalc is a Windows program that allows you to compare various motor/gearbox/propeller/battery combinations.

This program can be downloaded for a FREE 30 DAY TRIAL. If you like it you must then pay a $35 license fee.

LINKS

HobbyLobby (Best source for Graupner motors and gearboxes)

Bob Holman Plans (Old Time Plans)

MotoCalc (Electric Power System Calculator)