Blueberry's Motor...

view of engine

We know that motorsports fans always want to see the here's what's under the hood. All Formula V raceplanes use a 96 cubic inch, 4 cylinder aircooled engine. The rules keep the engine relatively stock so that the engines are as reliable as possible. In airplane racing, the consequences of a blown engine are a little more serious than in most other motorsports, because, without power, the airplane has to come down somewhere immediately! Although the raceplane could glide a short distance without power, it really helps to have the fan running at all times!

The sheet aluminum cooling baffles are very evident in this photo. Air enters the cowling through two slots just behind the propeller, and then is directed down through the cooling fins by the baffles. The hot air exits through a duct on the bottom of the cowl. Single ignition is used (rather than the usual two plugs per cylinder and two magnetos as in most aircraft). A Slick 4300-series aircraft magneto is used. The raceplane does not have an electrical system, and is started with a flip of the prop.

Also visible is the oil cooler (on top of engine) and the crankcase breather and air/oil separator (on firewall). Oil drains back into the crankcase from the separator.

An Ellison EFS-2 injector is used. The intake manifold and ram air box are located beneath the engine. All raceplanes use standard 100LL aviation fuel (100 octane, low lead). The fuel tank can be seen at the extreme right, and holds 10 gallons. Although the plane could fly several hours and go several hundred miles on a full tank of gas, we seldom fly the raceplanes cross-country. We prefer to trailer them to and from the races. Each race lasts about 15 minutes, and we usually use about one gallon of fuel per race.

We typically see 4,200 RPM in flight with this setup. The Formula V rules require a direct-drive propeller (i.e. belt or gear reduction drives are not permitted). This rule serves as an excellent horsepower limiter, because at 4000 RPM, the prop tips are doing over 700 Mph! As the propeller tips approach the speed of sound, the air drag on the tips rises significantly, thus much more torque is necessary to turn the prop a little faster.

Go To Blueberry Air Racing Team page