Weighing in!

[LA F2 Flyer]

So today was finally the day that all of the pieces of my Polini 303 have been affixed to the aircraft. As of now I am just short some safety wire and coolant.

I also recently completed the bracket for the ignition switch (a rather large box for what it does, it seems). I spent some time determining exactly where to put it, but think I sorted it out nicely.

Having completed adding all necessary weight, I was ready to grab the scale and see where I ended up. To be honest, I was pretty nervous about going over. I had build "dummy" scales out of plywood to ensure that the height of each wheel was the same with the scale as without it. (By the way, I trust the scale; I used it to weigh my plane after it had been weighed by a professional aviation scale, and it was within a half pound.)

Total weight of the craft currently?

260

Now, I know you are thinking "that's over!" And it would be, if I didn't have roughly two gallons (conservative estimate) of fuel in the tank. I am also not accounting for the weight of the handheld radio nor the steel brackets holding the wings in place for transport. To be honest, I'm surprised that I am still under.

This poses another question, regarding the cowl (which I have not weighed nor attached). This sort of coincides with the Merlin Lite discussion from another thread, regarding the weight of the Merlin with the cowl pushing it over the 254 limit. It was mentioned that parts not necessary to fly the craft could be excluded from the final weight (I am paraphrasing here); things such as seat cushions, handheld radio, etc. Why couldn't the cowl fall under this category as well? And what exactly is the written rule on this (if any)?

A quick Google search yielded little in the way of results, and I figured it could make for an interesting discussion.

[Mountain Cat]

The Badland is flying without a cowl, so it is not necessary for weighing. Since it's water cooled, a cowl is not necessary for flying airflow. Good job on the weight! Seat cushions, radio, etc. is not necessary for flight. You will lose the 6 lbs or more. The FAA won't even take a second look at you. The fuel and radio will probably put you under the number. Expect to change the main jet, the factory said it's a 122 which might be a little rich. Most from what I understand are running a 118 or lower.

[Kaveman]

I haven't made time yet to sniff through part 103 to try to find the legalese, but it is my understanding that "not necessary for flight" is pretty broad. I can't understand why the cowl wouldn't be covered but a door or seat cushion is. That said, it may be the top speed that bites your butt.

260 is great, friggin good job!bOff the top of my head, gasoline weighs 5lbs a gallon, so two gallons would put you back at 250, plus the weight of the radio and your bracket. I'd say you made weight pretty easily.

[Mountain Cat]

None of the stuff I listed is necessary for flight or weighing. You made weight, with gas at 6 lbs per gal. NICE!

[LA F2 Flyer]

I have to say I was pretty pleased.

Kaveman, if you do find the legalese, please share!

[LA F2 Flyer]

MC, the 122 main jet might be too large, but the run-in should tell me. I've added a foam pod air cleaner (which may breathe a bit better than the stock airbox) and am at a lower elevation than you (I believe) so we will see!

[Kaveman]

When y'all run in one of these engines, what's your procedure? I know I'm kicking at a hornets nest here, as there's as many ways to run in an engine as there is to build one.

I tend to run them rich, both in terms of mixture and I add extra oil to the fuel. Once I'm confident that the rings have seated all the way around the cylinder(s) then I ditch the extra oil and tune the engine properly.

Also what's your brand of oil? I run Stihl HP Ultra synthetic (the silver bottle) or Amsoil.

[LA F2 Flyer]

I'm glad you posted this question, because I was about to do the same! I'm curious to know as well. The Polini "manual" (after several scans) doesn't seem to address this.

I intend to run Amsoil in mine, but don't intend to mix with extra oil. (From what I've heard, adding oil to the premix actually creates a leaner mixture, as you are subtracting some fuel from the final air/fuel mixture. I can't imagine it's all that much, but what do I know?)

My method in the past has been to get the engine up to temp and vary the throttle between idle and 1/2 throttle for the first ten minutes or so, then go full revs for (very) short bursts to seat rings, etc. Of course that was for motorcycles, and an engine-out didn't have the potential for dire consequences like an aircraft does.

What say others?

[Mountain Cat]

Polini's are test run at the factory. Amsoil or Stilh syn are both great oil (syn-no carbon). I now run Amsoil due to it being a bit cheaper than Stilh. which ever is easier to get locally is fine. Both are excellent oils!

[ksatter26]

I have several quarts of Blue Max oil that I ran in my Hirth (MiniMAX 1103R) with good results. Recommended by RecSports, the Hirth dealer.

[Mountain Cat]

I've used Blue Max for a short time, but at 50/1 mix. I just prefer syn oil better. I even run the Amsoil Interceptor at 50/1. Polini wants 40/1 for their engines. Which is easier to remember, 16 oz to 5 gal.

[LA F2 Flyer]

I'll need to check the manual for the 303 before I run it. As I recall the 200 calls for 50:1.

[ksatter26]

Re-read the WONDERFUL Polini 303 Manual ... and had to do some calculations for the "recommended" 2.5% mix of synthetic oil. That's 3.2 fluid oz of oil per gallon which translates to a 40:1 mix.

The "run-in" instructions are also rather sparse:

Startup ... leave it idling until warm to "normal temperature." Suggest running 15 minutes at medium-low power gently accelerating with different levels of intensity,

Also, there are some sections of the English translation version of the manual that are still in Italian.

That's it from Polini.

[LA F2 Flyer]

Yes, I caught the section that was still in Italian. I jumped over to the Italian manual to see if that section was in English, but no love to be had there.

In regards to the rest of the manual, most of it probably wasn't worth the translation anyway. When you have such detailed gems like "Engine running poorly? - carburetor bad...fix carburetor"...

Thanks for doing the calculations for me!

[Mountain Cat]

That's butchered street Italian!

[LA F2 Flyer]

Haha, I wouldn't know...I don't speak Italian, street or otherwise!