I guess you will go without answers. I have flown two 180 hp Cubs, and all I can tell you is they are extremely heavy and do not have the same feel as the lighter Cub variants. They will go straight up, but I cannot get a 200' ground roll out of them. The CG of the Wip-equipped Cub needs aft ballast to operate legally. It needed that when it had a 150.
The McCauley 1A200 prop is 7-8 lbs heavier than the 1A175 on the weights I have documented. The 180 hp Super Cubs I have been involved with over the years have all bee nose heavy and several required weight in the back to be legal for flight when low on gas and flown solo. The Sensenich ground adjustable solves that issue and has a lot better performance.even with extended 3x3 gear? Cubcrafters claim you can get within 1lb of an O320 depending on choice of prop. With the borer prop it's 5 lbs heavier than the O320, 1lb less with sensenich
Maybe you ust need 35" bushwheels! haha
Just did the weight and balance on my PA-18 Clone, Titan XIO-370, Whirlwind Ground adjustable GA-200, Oratex fabric, three inch extended gear, performance flaps and 600 tires. Engine has magnesium sump and light weight fly wheel. All in empty was 1,111 LBS, Empty CG is 13.69. Tail weight at tail wheel was 62 lbs. Not flown yet, so we will see how it performs
Mine (Ex AB) is a bit heavy when compared with other's numbers. It has long wings and is on floats with tail ballast. Empty 1462# @ 14.4" CG. Performance is very satisfactory with good short pond (1000 feet with lots of room to spare) and climb with a high cruise speed. I could reduce the weight a bit with a lighter prop and reducing some of the ballast, maybe as much as 25 - 30#.
Why are you asking? Is yours not doing something you think it should?
Oz,Skywagon, your 1462# on floats puts you at about what, 1250-1260 on wheels? Not horrible by any stretch I’d say though I may be way off on that guesstimate.
Are you using the Pawnee prop or something light?
Oz
The McCauley 1A200 prop is 7-8 lbs heavier than the 1A175 on the weights I have documented. The 180 hp Super Cubs I have been involved with over the years have all bee nose heavy and several required weight in the back to be legal for flight when low on gas and flown solo. The Sensenich ground adjustable solves that issue and has a lot better performance.
A nose heavy plane can’t slow down as well as a tail cg plane. They also go over on the nose or back more often especially when low on fuel.
My 180 Cub has balanced fuel injected with dual electronic ignition. It burns 8 gallons per hour at 23" and 2400 rpm giving a 5 hour range with 1 hour reserve (48 gals). Just for the fun of it I pulled the power back to 4.2 gph and it cruised around comfortably at 70 -75 mph. Normal cruise speed is 105 -108 mph. This is on floats.The 180 HP cub I flew for several years was heavy to begin with and nose heavy also. A nose heavy plane can’t slow down as well as a tail cg plane. They also go over on the nose or back more often especially when low on fuel. The biggest problem I had was it consumed 10 gallons per hour as opposed to eight for the 160’s. That made it about a three hour range aircraft rather than a four hour range. I had to keep a belly tank on it all the time except when it was on floats and then I couldn’t due to the float rigging even though I needed it. So it was a heavy plane made heavier yet By the additional fuel and tank I had to carry. I’d not be inclined to have a 180 in a cub. If I wanted a 180 I’d buy a 180.
The CG of the PA-18 fuel tank is at 24". So, yes the CG will move forward as the fuel is burned.Does the CG of a PA-18 move forward as fuel is burned? That would surprise me since CG moves aft on an FX-3 carbon Cub. Attached graphic shows CG change between full fuel and empty for various loadings.
(edited to correct starting fuel for loading 2)
The CG of the PA-18 fuel tank is at 24". So, yes the CG will move forward as the fuel is burned.
Perfect, I like to fly at 19.5 -20". I find that gives the best overall performance and highest cruise speed. The only thing you may notice is a slight reduction in stability. Nothing to be concerned with.What is the best CG to travel with? When loaded and full fuel, it the calculates at about 19.5inches (assuming the W&B calcs are correct), very close to the limit.
The two PA-18-180 that I flew towing gliders were both "restricted" and both had lead ballast on the tail. I assumed that all PA-18-180 would be the same but it seems not. Why would some be "restricted" and need tail ballast but not others?
A lot of tow airplanes are Restricted.... Some FAA Inspectors don't understand that you can tow gliders or banners with Standard category airplanes and insist that the owners put Restricted certificates on them.
You can say that again. Years ago, I had an FAA inspector on Long Island issue me a restricted certificate of airworthiness on a banner airplane for which I never made application, nor was it inspected for the purpose of issuing that airworthiness certificate. Was I supposed to thank him? I wasn't exactly grateful as he then said that I couldn't fly overhead anybody. What did he think??? Was I going to tow banners over the outer banks advertising to fish? -- That airplane was properly equipped and certified for the operation in standard category. I had to go to Washington to get that straightened out. Eventually we were able get some Restricted category airplanes issued with ops limitations allowing for flights over congested areas without additional waivers. Some paper pusher later decided that wasn't good enough - based on nothing.
C'est la vie. :roll::roll::roll: