snipped

BTW I just talked with Tracy Saylor and he now claims well over 200

HP.

He has made some improvements in his engine and will run in next years

Sun 100

at Sun&Fun. He is also replacing the tail on his RV6 as it is a mass

of cracks.

Dave Anders has been through two tails on his RV4 so far. Some say it

only happens

with a constant speed metal prop and other say it is higher HP on the

O and IO 360

engines running over 2700 RPM and or airplanes going well over Van's

VNE specs.

With four smaller power pulse per prop rev rather than just two  we

are in

much better shape vibration wise than the O and IO 360 four cylinder

engines.

Paul Lamar

Charlie and Tupper England wrote:

My O-320/160 hp wood prop -4  (~500 hrs) has them at almost every
stiffener. The longer it flies, the more cracks I have.

Recommended prevention is to put a bead of RTV in the trailing edge of
the rudder to prevent flexing at the last rivet on the stiffener, since
there are no ribs connecting the 2 sides of the rudder.

Most early RV-4's get these cracks, at least on the rudder. Going faster
may make it worse, but I've not heard anyone blame it on horsepower
before.

Question for Tracy: Do you have the RTV in your rudder, & if not, do you
have cracks?

Charlie

(purchased) flying -4

Tracy Crook wrote:

I do have the RTV at the stiffeners and have not seen a single crack
anywhere after 1050 hours.   I think the greater number of power strokes
with the geared rotary (hence lower vibration) is a big advantage.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

 
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