RE: Wild Hare EXTRA 300 28% and MT57 CN
Sorry for taking so long getting back to you but I have been very busy lately. Finally I got everything together and the plane seems to be ready to fly.
Today I run the MT-57 for the first time. I used a Bunny prop (Xoar type) 22X8 for the first run. The engine took a few flips for the diaphragm to get wet to the point where it would bring the fuel to the carburetor. I had to open the diaphragm back plate and prime it as it was dry.
After that the engine fired right up. A couple of choke flips with the throttle open until it popped and then opened the choke, ΒΌ throttle and the engine fired right up.
I was actually impressed how nice it idled. The needle settings where not flyable, but close enough to get the engine running (the settings were on the extreme rich side).
There are some videos that I posted on Youtube follow the links to see the engine running.
[link]http://www.youtube.com/watch?v=EdD7JCr_OGQ[/link]
I was not really impressed with the performance with the 22X8 prop as it gave about 6800 RPM and about 25 lb of pull ( you can see the video).
[link]http://www.youtube.com/watch?v=I0YsCXHS_XI[/link]
The idle of the engine especially after running it for only 10 minutes is incredible. The engine can hold reliably 1400 RPM and if pushed it can reach 1200 rpm. I can assume that it can get better once the engine brakes in.
[link]http://www.youtube.com/watch?v=2XHRbWBPkzI[/link]
I was getting some type of popping sound on the high end RPM and any kind of carburetor adjustment did not seem to get rid of it. It turns out that it was a timing issue as it was set low. After advancing the timing approximately 3 degrees the high end RPM smoothed out.
The transition is very smooth and low and high RPM is constant.
Later on I decided to change the prop to a 23X8 (Bunny-Xoar type) and that is when the engine came to life. The static thrust increased from 25 to 27 lbs and the engine seemed happier. Unfortunately I do not have a video of this as the batteries of the camera died.
I will later on post performance numbers with this prop as well as a video. At one point, while holding the plane (weight is 16 lbs), I pointed it towards the sky at full throttle and it literally wanted to take off like a rocket.
I m planning to fly the plane with this engine this coming weekend.
If there is someone else out there that has any input please share it with us.