Second flight

I did fly last Friday as planned. Rather windy and with strong thermals, i.e. not the ideal conditions to make precise performance or consumption measurements.

For the next flight I will do some prop adjustments by increasing the pitch even more. I know little about props but I have the feeling I don’t get the most out of the current setup. 

The first consumption number after 1 hour flight in rough conditions is ~13 l/h (3.4 gallons US/hour).  This is 25% less than my 532 at comparable speed (but with incomparable takeoff and climb performance). However, don’t consider this as final numbers!

First flight experience and sound

Following Peter’s advice I adjusted the propeller pitch before my first test flight. This was the first time I’ve touched the pitch and I had been told that 1° is about 300 RPM for 60hp. I started with 2° and got 6350 RPM static. Another 2° got it down to 6100. That should do for test flights and I will fine tune later if required. But the more pitch the less power at takeoff and climb. 4° appeared to be a lot... 

There is nothing you can’t do with an iPhone (the app is iHandy Level)

For the first time in 21 months I was about to fly again... lined up at the end of the field, full power, breaks released... oh yes, there was takeoff power left. Must have been my shortest takeoff ever in despite of the light tailwind. Acceleration and climb... a little too concentrated on flying to verify the climb rate (will do that next time) but it was steep...

I did 3 takeoffs (and obviously 3 landings) for a total of 35 minutes in the air so I don’t have more than first impressions to share. I hope to fly again Friday this week.

Both on the ground and in the air the sound is lower than 532/582. That the exhaust pipes end almost behind the pilot, rather than in front of the pilot, obviously helps to lower the sound in the cabin.

Power at takeoff and clime is very satisfying.  Cruising 110 km/h at 5000 RPM (to be confirmed) no vibration and acceptable sound when removing the headset.  No tendency to vibrations at higher RPM and stay at set speed.

Click here if you want to listen to the Italian tigress’ roar. You can either listen directly using the player at the page or download the mp3 file. The recorder is set on the ground about 1 meter from the wingtip and the plane secured.  There is some wind noise, sorry about that... It almost sounds like 2 engines running in parallel. I wonder if this is due to the individual pipes or if there is some carburettor fine-tuning to be done.

Roaring Italian tigress at 6550 RPM static

I was out at the field at lunch today. I installed the new Tiny Tach and had the engine running again. Started very easy again at first try.

Static I get 6550 RPM at full throttle. This leave room to optimize the prop setting but I should be able to fly without modifications.

I had decided not to take off today so when releasing the breaks at full power at the end of the field it required some concentration to actually stay on the ground. The acceleration is impressive.

To raise the tail at standstill and turn on rudder is not a problem. You can dose the power very precisely. While taxing around at various speeds for almost 30 minutes all indicators stayed in the green.

I will check CG and do a serious pre-flight check on all the new bolts but I cannot think of anything else between me and the first flight behind my Simonini Victor 2. 
According to the weather forecast this might be Sunday this week.

Stay tuned...

Finally and Wow!

Everything connected and ready to run!

 

There are some minor details that will be done later but today I took my bird down to the field to test the engine for the first time.

I had charged my battery over night but it didn’t stand a chance. The compression in the Simonini has nothing to do with my old and tired 532. Luckily we always have a fully charged regular car battery at the club and with that the engine fired as soon as the fuel reached the carburettors. A few seconds of choke and she was running smoothly. Maybe a tendency to vibrations at low rev but I run with the cowling open due to the external battery so that will have to be confirmed. However, steady as a rock at higher revolutions. Unfortunately my old Tiny Tach was not compatible with the new ignition (bailed out at 9999 rev/min...) so I could not safely test the full potential. I’m expecting that I have to adjust my prop (or replace it) so I was afraid of exceeding maximum RPM (6200). A new Tiny Tach should be arriving later this week...

First impression was really “Wow - this is more power than I expected”. I was impressed and so was the crowd that had gathered. There is no question that I have more, much more, power than before.

The sound is exciting, not too loud and not to high pitch. Appears lower from inside the plane than my 532. 

Exhaust system in place

I earlier announced the installation of the exhaust system to be the next challenge. The reason was the length of pipes in combination with the landing gear. It turned out to be easier than expected.

The double exhaust elbows allows a very free positioning of the pipes and it was not too difficult to find a position, slightly across rather than straight, and have them fit between the legs of the landing gear. 

The 4 springs on the exhaust support are expected to keep the pipes level and maintain the required distance to the legs (the attachment in the front will be replaced with a second rubber damper) . The harder landing the less distance...

A slightly increased opening in the lower cowling...

Finished... at least almost, some silver paint and that second rubber damper is missing, but still...

So what is left? All connections are completed on the engine side of the firewall. I’m currently updating the dashboard. If all goes as planned I should b able to start the engine this coming weekend!