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Permalink Reply by Fred John Thomas on September 25, 2019 at 7:46pm

What is your static?

How did u damage the plane?

My 3 litre is at 8.5 degrees 2800 rpm static 

Shure seems like alot more than 300 lbs theust3

Should be more like 600

I plan to test mine

Please for the love of god talk to ww

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Permalink Reply by Mark Baenen on September 26, 2019 at 8:13am

I've done a lot of tests changing pitch on my 2.7l Corvair with a 66" warp drive prop - everything from 6 degrees up to 12

These measurements are done with the Warp Drive protractor on the back flat part of the blade with the top engine cover level. I ran into detonation on a hot day with the pitch at 12 turning 2400 static. Climb performance is horrible at 6 with a static rpm of close to 3000. Right now I'm at 8.5 also with a static of 2800 and unloaded at 2850.WW writes that minimum static is 2700

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Permalink Reply by james a board on September 28, 2019 at 3:11pm

Hi Mark,thanks for your comment.this plane has about drove me nuts.I can’t seem to get any real info.even from warpdrive.I guess I’m dumb ,but you’re referring to static rpm. As wot? My wot is 3200 rpm.I’ve had from 6.5 to 12degrees with no rpm change so I’m confused..I had 12 degrees the last time I tried to fly it and ended up in some trees.had to rebuild both wings.shouldn’t some type of degree pull this engine down...

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Permalink Reply by Ken Pavlou on September 28, 2019 at 6:21pm

Static RPM is the maximum RPM's achieved on the ground at WOT with the plane standing still.  During takeoff as the plane accelerates you should gain some RPM.  We also measure WOT RPM in straight and level flight. Aside from being in a dive, WOT in straight and level will be your max RPM.

In your situation 12 degrees sounds like its too much and 6 too little pitch.  The 12 degrees won't give you 2700 RPM static which leads to detonation and overheating along with not getting the proper HP out of the engine. Its like trying to move a car from a standing start in 5th gear.  Conversely, too low of a pitch gives you lots of RPM but not enough bite to accelerate to safe airspeeds.  Its like never shifting out of 1st gear in a car, the engine is screaming but you're only moving 15 mph.

You may also want to check your tachometer for accuracy.  6-12 degrees of pitch is a large range to not cause any noticeable change in RPM.

-Ken

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Permalink Reply by Ken Pavlou on September 28, 2019 at 10:47am

When I was running a 2700 cc / Warpdrive combo in my 601XL I set the prop pitch to 9.5 degrees at the tip on the bench using the warpdrive protractor.  This resulted in a static RPM of 2750 and a WOT RPM of 3100 in straight and level flight. I suspect with a slightly more draggy airframe you'd run a little less pitch.   Do not fly if the static RPM is less than 2700.  Also, make sure your ignition timing is set correctly with a timing light.

-Ken

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