A hollow tube has more strength than a solid one... How many solid round bar roll cages do you see? I has solid ones on my avid once and they bent way easier than the tubes. Tubes will flex and return to relaxed position whereas solid will just bend. The 4130 tubing is available on spruce, but I think Matco might heat treat their axles as they are less prone to bending.
The wood fairings on the struts are structural and are required. I upsized my struts on both diameter and thickness and then used the plastic fairings from kitfox. I keep threatening to pull those off and come up with a lighter weight fairing for the wing struts as the plastic ones are heavy!
Do a search for janitrol heaters... they are in lots of certified aircraft and are flying every day without blowing up... they also only seem to work about 1/3rd of the time My buddy has a lake with one in it that is not working and its almost 3k to replace it. Right now he is flying with a 12v ceramic heater in his plane...
on our planes the lifes blood is the coolant. The more plumbing we install the more potential leaks we introduce. Not to mention that plumbing gets heavy fast. I took 2 heater cores out of the inside of my plane when I got it. I think I would rather deal with a the diesel heater I have never had troubles or issues with versus more potential ways to shut down the engine. small leaks over time are easy to not notice. Say what one wants about the fuel consumption on the heater and the BTU output. Burner technology is a wonderful thing and one can be made to burn hotter or cooler. Yes gallon for gallon is has XX BTU in it, however, the actual heat output can vary greatly. Dump a gallon of diesel in a bucket and light it off, then run the same amount through and efficient combustion chamber. Tell me if you get the exact same amount of heat off it. I already know the answer and I already have first hand experience with the amount of heat I get off these.
its 8kw.. or 27000 BTU. The flame is in a sealed combustion chamber just like the janitrol heaters in lots of other aircraft. I have the scoop on the back of one rad from (mkIV) putting the air straight into the cabin, I also have a 2" hose coming off the other rad into a heat muff and coming into the cabin. I can fly pretty comfortable down to around -30 but only if I keep the RPM pretty high. When I was flying with a buddy who was in his Tcrate I had to pull the RPMs back to around 5200 and it was COLD. At any rate, I am going to order another one for the plane, probably get the 2KW heater for it as that is what we put in a buddies 24' boat and it keeps the cabin nice and toasty on it.
I will be shaving a lot of weight off it as there is no real need for the long pipe runs etc. Also don't need the muffler on it, just a straight pipe going out. I think the 2KW would be more than enough as these things really do put out some good heat! I could even mount it in a "belly pod" so its all self contained under the plane then just pipe in the heat under the seat.
Any good sled shop can reseal it for you. I have done 4 or 5 582's myself. The rebuild manual is on this site and the dvd "deep inside your rotax" pretty much walks you through it. Buckchop on here is in Fairbanks and has a shop he used that resealed his engine. I don't know anything on the other shops up there.
I am actually tempted to put one of these in the bird. I have put one in a boat and I just got this one to put in my motorhome. The put out good heat, don't draw much juice and will burn less than a gallon in 24 hrs running on high the entire time. A lot of certified planes use the janitrol heaters that burn gasoline but I kind of like the idea of diesel or kerosene better than gas..
I went to look at it with akflyerbob.. He is the one that has to have at least 4 airplane projects going at one time all the time. the sad truth is that's no shit.. I think being retired he has to build and sniff poly tone to keep him young.