Wait so now I'm throwing credentials around!?! Your funny Mr NHRA.
I have not blamed anyone for what happened I've simply explained our experience just to be clear. I own the plane and my friend owns the engine. We fly together and he's been around this hobby for many years.
On the ground before the first flight the engine was run up to temp, carb tune checked, peak RPM checked and no it did not exceed 6000 on the ground. This process was slow and methodical, not rushed at all. We checked and talked about it and then decided to go up. Every indicator was positive and our collective impression was good to go, per usual hobby practices.
Why should we expect an 8-10% increase in RPM to cause the engine to fail? That's a small gain. What we are more interested in is better response and no stumbbling in the mid range. We also see good fuel economy and even temps, all good indicators.
The biggest noticeable difference was the prop blade chord length. Other props have a wider blade and are not called or classified as wide or pattern or 3D. The Mejzlik prop has no classification other than its a standard prop so to speak but clearly there is a difference.
What we clearly don't know is the true power of this engine or its limits in real figures because nobody has provided that info. That should be the responsibility of the person or company that makes the mods or aftermarket parts to improve an existing design. As a result we have been testing with 24 inch props and adding pitch while taking temps and tach readings. Like I said I have an onboard telemetry tach coming this week so I'll have more info soon.
One other thing to note: Altitude Density
You could have the perfect prop on a plane one day and the next time you go out you could here it ripping in the sky. When the density of the air changes the load on the engine changes too.
On one day in particular I couldn't get a simple new micro heli to lift off from the ground. I added 3mm more chord length to the trailing edge of the rotor blades with packing tape and then it flew. On that day the Altitude Density was over 6000 feet but we are 2240 feet above sea level.
Its a good idea to call you local airport for a weather report just to see what's going on with the air near your flying site. They have automated weather reporting by phone. Mine is on speed dial under Pappy Boyington, lol
Last edited by Chris Nicastro; 10-04-2016 at 07:44 PM.