My new plane

1/2A Nut wrote:Looks great good job on the build!!  
It should be fast. The muffler will need it's exhaust tip to the side so oil doesn't
collect in the muffler. Down being the best solution for complete oil drain.

Ken Cook wrote:         One thing that grabbed my attention is the tank, at least from the pictures it appears as if the engine is sitting on the beams and the tank is shimmed up considerably higher. This could really make the engine go lean when inverted vs upright. Unless you absolutely know where the height of the pickup tube is soldered within the tank I would just be aware to that situation and set the engine off slightly rich. Once you do a outside maneuver, it will become quickly evident if the tank height is set correct. Balance the plane where the front leadout exits the tip. This will almost always place your plane in a nose heavy condition and work from there removing it to make it more maneuverable. When the power cuts, examine the plane's glide path on it's return to the ground.  If it's too nose heavy, remove the muffler because it robs about 1500 rpm's. It retains a lot of heat as well.

getback wrote:She looks really good oldguy , hope to see some fun in the air with it good luck with the maidin

Ken Cook wrote:        We tried the AP .15's for combat. They didn't offer the same power as the Norvel and the FP .15 were offering. I like them nonetheless. We then used them for some other racing events we were experimenting with. When we ran them, we took off the muffler and left the exhaust just exiting the case. We would RTV a piece of ply to the front of the tank smeared in it to prevent heat on the face of the tank.

Ken Cook wrote:This is a tough question for me to answer. In addition, my use for the engine was solely combat which isn't the same as stunt or sport.  The AP is ball bearing, the Fox .15 slant and steelfin aren't so there's going to be a considerable smoothness and rpm increase using the AP. The AP is also ABC which neither of the Fox's are and that in itself limits the Fox to really being pushed hard. What I can say about the FP and Norvel .15's were that we were seeing 20K plus rpm's using a 7x4. I even think we could've been using the APC 6.3x4 combat prop.  The AP was close but not 20. The Fox .15X isn't afraid of nitro.I don't see 20 K with the Fox.  I have run the engine on 50% nitro and it screams. I don't make a habit of it but I just love those engines and they just impress me for how archaic they really are. Your probably aware that there's a shim under the cylinder liner to decompress the .15X. That can be removed which can almost put 1600 rpm's to the engine. It might need a additional head gasket for piston baffle clearance if removed.

Phil Cartier of Core House products was using the AP engine for about 2 seasons. The crankshaft broke on his engine. The crankshaft diameter is small on this engine. In Phil's situation, this could've been a hard landing, it could also be a result of us running these hard. I never inspected or concluded a decision with the engine. I jumped on it due to the low cost true ABC construction and thought it would suffice for our events.

   It's quite difficult comparing old iron to new technology. I love them both and I favor the new stuff in terms of reliability but I love the old equally even though I might wear my arm out flipping them at times.

Ken Cook wrote:This is a tough question for me to answer. In addition, my use for the engine was solely combat which isn't the same as stunt or sport.  The AP is ball bearing, the Fox .15 slant and steelfin aren't so there's going to be a considerable smoothness and rpm increase using the AP. The AP is also ABC which neither of the Fox's are and that in itself limits the Fox to really being pushed hard. What I can say about the FP and Norvel .15's were that we were seeing 20K plus rpm's using a 7x4. I even think we could've been using the APC 6.3x4 combat prop.  The AP was close but not 20. The Fox .15X isn't afraid of nitro.I don't see 20 K with the Fox.  I have run the engine on 50% nitro and it screams. I don't make a habit of it but I just love those engines and they just impress me for how archaic they really are. Your probably aware that there's a shim under the cylinder liner to decompress the .15X. That can be removed which can almost put 1600 rpm's to the engine. It might need a additional head gasket for piston baffle clearance if removed.

Phil Cartier of Core House products was using the AP engine for about 2 seasons. The crankshaft broke on his engine. The crankshaft diameter is small on this engine. In Phil's situation, this could've been a hard landing, it could also be a result of us running these hard. I never inspected or concluded a decision with the engine. I jumped on it due to the low cost true ABC construction and thought it would suffice for our events.

   It's quite difficult comparing old iron to new technology. I love them both and I favor the new stuff in terms of reliability but I love the old equally even though I might wear my arm out flipping them at times.

Ken Cook wrote:        Very good questions. I will start by saying I have never found the Fox's to be happy on a 8" prop period. Fox's like 7" props and if you have wood even better. If your using a 7x6 your going to have more speed but this is also going to taxi the engine in the maneuvers. If your hearing the engine sag a little in the maneuvers, then I would drop to a 7x5. There's nothing wrong with a 7x4 but I wouldn't use a G/F series 7x4 on a Fox due to a very thin blade area. Fine for newer Schneurle ported engines but the Fox likes a bit of a load which is true of most Fox's. Now if you have a older wider bladed 7x4 Master Airscrew all the better. Taipan 7" props work very well if you can source them. It comes down to experimenting and lending your ear to the engine and paying attention at or nearing 1/2 tank as the head pressure in the tank lessens and the engine leans out. This is about 2.5 minutes into the flight and the plane should be really  going faster than when launched at this point.

              Many of them have had that shimmed removed. I'm not even certain what years they were offered or always offered. I just know that I take them out. It's good to see that your using them. Many have formed such a negative opinion in regards to that engine.

Ken Cook wrote:       Most of your older engines tend to do better with wood props. It's easier on the engine because they're lighter therefore the rpm's are a tad higher vs a heavier composite prop. I also strongly believe that the lighter prop not only keeps the CG aft, it allows the plane to turn quicker just because of the gyroscopic forces at work.   The other thing is that most of the wood props are a bit lighter on pitch than what is printed on that prop. Rev-Ups for instance if you checked them with a pitch gauge usually come out a 1/2 pitch lighter than what is stated. These props tend to just let the engine run happy throughout the run. Newer props such as APC work very well because of their shape and the fact that their pitch is usually true. In this situation, it's better to drop a size in pitch when using them because it will absolutely load the engine when pushed into hard cornering maneuvers.