None!

You don't have to use more than 165 HP.

The 165 HP NA Lyc engine becomes 115 HP over 12,000 feet.
The 250 HP NA rotary engine becomes 175 HP over 12,000 feet.
Flat rating without a turbo.

Van's airplanes have strict VNE's. Bad things happen when the VNE is
significantly exceeded. Tails have fluttered and come off. The 9A
tail has probably been improved over the earlier models. Never the
less don't exceed the VNE.

It is true. People have gone faster in various competitions with
Van's airplanes than the VNE but they have beefed up the tails in
most cases. IMHO I suspect part of the problem is the vibration
characteristic of the aircraft piston engine. I know engine
vibration enters into the equation for flutter. The rotary is much smoother.

Another factor, for some strange reason, is composite designs
do not seem to have this VNE/tail-flutter problem. IMHO I suspect
this is due to the higher damping characteristics of composites over
metal. Carbon fiber movable control surfaces would have a better
stiffness to weight ratio and require less balance weight. On the
other hand there are more RV's out there.

Paul Lamar



As per the KISS requirement, p-port rotor motor. You could use the Holley 2
barrel carb. Beef up the tail as Paul mentions for the instance when something
distracts you and VNE gets exceeded. I have noted in life-- shit happens. More
power is always better and the throttle can always be pulled back to control
the speed. Climb and take off would be good. By the time you get there with
the install a source for an axial flow turbine for power recovery may be
figured out for better economy. The engines qualify like the old Timex watch
ads; take a licking and keep on ticking.

Dale Davies


I beefed up the elevators on my plane by using .005 thicker than stock skins
on the elevators.  I also used the extruded trailing edges so my elevators
have a 1" longer cord than stock.  There was a problem with skins cracking
on RV-4s at the aft end of the skin stiffeners, so I think my mods probably
addressed the problem.  Hope to have my plane back in the air by the new
year, I'm foaming up the underside and will be e-glassing the new air scoop
for the heat exchangers.  No fun working in a 36 degree hangar, but I gotta
get back up in the air.


Brian Trubee

What sort of horsepower does the 13B produce with standard fuel injection
and a turbo?

Pierre Swanepoel

Stock 1993 2nd gen Turbo II 210 HP.

Late model 2003 3rd gen  RX7 with dual sequential turbo's
280 HP. Not imported to the states.


Paul Lamar

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