Panther Sport Aircraft Forums

don't forget about the Lycoming 233 and or the AEIO 233 engines... a good mid range choice of 120 hp and lighter than the 235 engines.

Doc

Paul,

Forgive me for coming late to the party, but why didn't you folks use the full 1320 lbs for the LSA Panther design...seems that would increase flexibility a bit? I guess a longer wing would decrease roll rate but also increase stability but it is a very cool plane as is.

One thing that Dan and I would like to clarify, if we do increase the maximum gross weight, it will NOT apply to aircraft that is being used in the LSA category. To meet LSA criteria for stall speed, the gross weight of the Panther CANNOT exceed 1115 lbs with the long wing. This has nothing to do with the actual gross weight capacity of the structure.

As you will probably remember from ground school, stall speed is a function of weight, wing area, and lift of the wing. With our wing area and lift available, we had to lower the gross weight slightly during testing to meet the stall speed requirements. In the US, we are not allowed to use flaps in order to meet the stall speed requirements for LSA. An LSA aircraft stall speed is based on the clean configuration.

The moral of the story is keep it light, especially if you intend to use it in the LSA category.

I am not an expert in fuels by any means, but in studies that I read about on the effects of ethanol, here are some of the important problems.
1. Ethanol can damage some rubbers, plastics and sealants.
2. Ethanol absorbs water, and from what I read, that mix can form an acid, and cause corrosion of some types of aluminum and other types of materials.
3. Ethanol based fuels do not have a very long shelf life before they start breaking down. It is in the order of a couple of weeks, AVGAS can last a lot longer, more like months due to its formulation and additives.

There are other reasons as well, but these are the easiest to understand.

So, why can cars run it? They are designed with materials to withstand the detrimental effects of ethanol, not just in the engine, but the entire fuel system from tank to pumps to the injection system. And most people will use up a tank of gas in a car in a couple of weeks, so it doesn't it doesn't go bad in that time, and doesn't absorb as much moisture.

Most planes end up with gas sitting in them for long periods of time without being used (unless it is on a cross country trip). So they have more chance to go bad and collect moisture.

Basically, the longer you leave ethanol based fuels sit, the more problems you will have. Use it quick no matter what vehicle or equipment you use it in.

I think Ly Con says they can get 4 hp per cyl. with their "head smoothing". Add in some gains from electronic ignition, throttle body and a good Vetterman exhaust a 160 hp 0-320 might see an easy 180 or more with 9:1 pistons. Bump up to 10:1 pistons and 200 hp isn't out of the question...maybe.

Hi test mogas without corn is best but I think it's the potential problems with seals, hose and the like with the dreaded alcohol. Maybe someone smarter than I can confirm or comment on that.