Scott Cable wrote: > 1.) The heat muff is secured by wrapping safety wire around it? What prevents vibration from allowing the heat muff to move around and start chafing the header?
What keeps it from moving is the fact that it straddles the down pipes through very tight fitting holes that keep movement to under 1/32", and it's wrapped tightly around the stainless steel spring. I clamped it in place with hose clamps, ran the safety wire around them (and it's trapped in those same holes), and then removed the clamps. It's rather tight, and not going anywhere. I used safety wire because it's far lighter than hose clamps. If it'll make you feel better, I'll wrap three more rounds around it, and run them through holes to guarantee that they stay put. > 2.) I noticed what appeared to be platenut holes for the carb mount, yet you stated in the text (2nd to bottom picture) that you needed to get your daughter to start the nuts. In your improved (next) version will you utilize platenuts? The reason I didn't use them yet is because the carb is threaded for 1/4-20 studs, so I'll either have to drill out the threads or use 3/16 bolts and nutplates (which is what I'll do). Next time it comes off I'll add the nutplates anyway, now that I know what a pain it is. That'll be before it flies. > 3.) The air filter looks like it needs something to support it in the center. I appreciate your concern, but I don't think so. It's only 3.5" tall, and supported all the way across the top by an aluminum angle, and has 6 screws holding the bottom. I'm not worried about it. > 4.) Please re-think the emergency air-valve. Adding it would serve two functions: > a.) emergency air source if both valves are shut. > b.) Act as an additional source of cowling air if the heated air from the muff is inadequate for conditions. That's why I said I was going to do a slight redesign and allow it to open automatically, so the engine can't be starved for air. I assure you that this heat muff will supply more than enough warm air for any condition that I will be ever be flying in. > Don't use a magnet, but rather a very light helical, torsion spring to keep the valve closed until it was necessary. If you hinge the emergency air flapper around the existing ram air valve pivot, you could add an additional hole to front of the airbox, and at least the emergency air source would be filtered. But if I had a hole that was open when the ram air was closed, I'd cut the effects of my carb heat muff in half, because I'd only pull half as much air through the heat muff. > 5.) I was more than a bit suprised not to see the airbox made out of Carbon Fiber or at least fiberglass. As I mentioned, the aluminum provides stiff flat surfaces to mount the valves on, that are not susceptible to deformation when heated. I may make a composite one someday, but the valves will be mounted on aluminum planes for that reason. Thanks for your comments. Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --------------------------------------------------------------
