facthunter Posted February 23 Posted February 23 Pure AL has a fairly good resistance to corrosion As the Oxide Protects from further corrosion. Look it up and also ALCLAD use. It does need looking after as does almost anything else. Bronze is pretty good( Copper-tin) and even pure Fe. made In a Puddling furnace and wrongly called Wrought iron these days. If you know what to look for you'll find it on old shipwrecks used on the chains and anchors. The metal appears layered because it is. It's folded and welded under the Hammer, many times.. Nev 1
BrendAn Posted February 23 Posted February 23 23 hours ago, facthunter said: Isn't that what the prop extension is ABOUT? Nev wouldn't that be to keep the cowling standard as blue said.
kgwilson Posted February 23 Posted February 23 Very few products are pure aluminium. It is too soft. Most are aluminium alloys with varying degrees of corrosion resistance. As soon as aluminium is created and cools a cost of aluminium oxide forms on the surface creating a barrier to corrosion. Introduction of other corrosive elements such as salt will begin the corrosive process. If you wash un-anodised or unpainted aluminium regularly it will last for a very long time. After WW2 most pots & pans were made from scrapped aluminium from aircraft. They didn't corrode though some got pitting due to introduced corrosive elements. Most got scrapped again when stainless steel came in to vogue. The grade I built my aircraft is called 6061-T6. It has magnesium, silicon, copper, & chromium, in it & the T6 is the tempering number. It has high corrosion resistance excellent welding capacity & high strength which is why it is great for aircraft. Back in the 70s I built my hang glider out of the same spec & other than new carbon fibre stuff that is what they are still made from. 1 2
BrendAn Posted February 23 Posted February 23 23 hours ago, facthunter said: There's always the Old trick of moving the Battery further back and the advantage of that is you can calculate exactly how far you have to move it before you do anything. Being a fair way from the CofG (long moment arm) it has a lot of effect.. You have to start Nose heavy though. Adding/moving a weight that is not a part of the Plane is a waste and Last resort. Nev the jabiru lsa 55 that i wish i had never sold was 912 powered and the battery was about a foot behind the fuel tank in the back and the oil tank was beside the fuel tank behind the right seat. the expansion tank was under the panel on the right side. it was a pretty tight fit in the center console with the fuel lines and 2 half inch oil lines and battery cables. 1 2
facthunter Posted February 23 Posted February 23 The one with the throttle between your Legs? They actually get along pretty smartly. First Jab I flew at Lethbridge. Owned by Gary Baume. Nev
BrendAn Posted February 23 Posted February 23 1 minute ago, facthunter said: The one with the throttle between your Legs? They actually get along pretty smartly. First Jab I flew at Lethbridge. Owned by Gary Baume. Nev yes.it was the first production jabiru. serial 003. 001 and 002 were 582 powered prototypes. the 1600 motors were not good 2 up training so hedley flying school in queensland got an stc from casa and had 3 of them converted to 80 hp 912s. it lives at castlemaine now. 3
facthunter Posted February 24 Posted February 24 The First production Jabs had KFM motors in them which ceased production and Rod Stiff had to make his own Motors as he didn't ever want to have to depend on other engine manufacturers again. Nev
BrendAn Posted February 24 Posted February 24 1 hour ago, facthunter said: The First production Jabs had KFM motors in them which ceased production and Rod Stiff had to make his own Motors as he didn't ever want to have to depend on other engine manufacturers again. Nev yes it would have been the kfm. great motors but under powered. 1 1
Rapture Posted March 5 Author Posted March 5 (edited) Earlier on in this thread, discussion arose about the proximity of the oil filter to the exhaust. Here is a photo of the clearance that we have with our installation. We will look at whether any insulation is required in due course. There is adequate clearance to allow the filter to be removed with the exhaust in place. The composite channel that you can see in the above photo is being bonded to the inside skin of the lower cowling. This is an air duct for cabin heat. It extends from the intake at the front of the cowl back to the heat muff around the exhaust, with scat hose connecting the composite duct to the muff inlet. The radiator is to be installed in the forward lower cowling. Our radiator is close to double the area of the standard Rotax cowling. The radiator mounting frame is attached to the lower cowling by 8 fasteners, allowing the fasteners to be released to remove the lower cowling without needing to disconnect the radiator. The engine mount turned out so well. I keep admiring it every time I get sent photo updates about the installation. All in all, it is coming together nicely. We are starting to get excited to test fly our 109hp J160. Edited March 5 by Rapture 11 2 1
Rapture Posted March 6 Author Posted March 6 (edited) The cabin heat air intake duct has now been fully bonded to the lower cowling and the photo below shows the scat hosing geometry from the intake air duct to the heat sleeve around the exhaust pipe and then out to the cabin vent. Fasteners yet to be applied as this was a trial fit. Edited March 6 by Rapture 4
Marty_d Posted March 6 Posted March 6 (edited) Oh, that's a good idea. I thought cabin heat usually came from a muff around the muffler itself, but taking it off an exhaust pipe makes sense. Edited March 6 by Marty_d 1
facthunter Posted March 7 Posted March 7 The shrouded exhaust pipe still needs air over it when the heater is NOT being used. Nev 1
skippydiesel Posted March 7 Posted March 7 4 hours ago, Marty_d said: Oh, that's a good idea. I thought cabin heat usually came from a muff around the muffler itself, but taking it off an exhaust pipe makes sense. It seems to me, if using the exhaust heat (there are other option), you would take the heat from where you will get the best result (volume & temperature of hot air). If the builders have determined that the exhaust pipe, rather than muffler will deliver what they want - all good. Using the exhaust system to heat cabin air is the tradition method , with the known potential for CO poisoning & transmission of engine noise. Safer quieter alternatives are available. Alternatives heat sources that seem to be viable are - Cooling System (hot liquid) Coolant Radiator (air) and Oil Cooler (air). The Cooling l system can be plumbed and controlled much like a car heating system but requires additional hoses, valve , small heat exchanger and fan. Likely to be relativly heavy & complex compared with the other systems. There is no chance of CO poisoning. As heating will be tied to engine temperature, may be slow to get going. Coolant Radiator - I have seen a design where hot air is taken from the back of the radiator & reticualted in a similar way to the exhaust heated air . The upside to this is no chance of CO poisoning. Once again may be slow to get going. Oil Cooler - similar to the above. A the use of thermostats, in all of the above, would speed hot air delivery and may make the system less prone to temperature drops, when at low power (descent)😈 1
facthunter Posted March 7 Posted March 7 Too Many "Mays". Also keep it simple. Using coolant will slow engine warmup and perhaps also make it run too cool in already cold conditions and there's more than enough water and oil Pipes already. Any under cowl source is suspect to contamination Possibilities. You want something simple that is tried and tested and Proven to work.. Nev
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now