Bill:

I pulled out the plans of my kit and laid my new OS 46 FX over them. While it would fill the space, it appears that my .46 would fit, so I envision that your .40 would fit also. However, the kit recommends a .19 to a .35 - and that was back in the weak engine era of the early 60's- so I wonder if your more modern .40 might not be too much horsepower for this little airplane. I have a couple of OS 20 four strokes that would probably do a good job of fitting in the little airplane, but I would be afraid that their horsepower would not be as high as the .19 minimum recommended by the kit. They were good R/C free flight motors. I do have a couple of OS 32 abc's also but they are screamers and, again, might overpower the airframe.

I have never owned the OS 40 LA, so I am unfamiliar with its performance. But if you intend to use it with a throttle, maybe its operating parameters are within the .19 to .35 engine range recommended by the kit. If it is tight due to the wood construction, maybe you could pull a fiberglass cowl to gain more interior room. Don't give up on it. Good luck.

Jim Fruit

Might consider going electric.  Clean and reliable.

Bill:

I pulled out the plans of my kit and laid my new OS 46 FX over them. While it would fill the space, it appears that my .46 would fit, so I envision that your .40 would fit also. However, the kit recommends a .19 to a .35 - and that was back in the weak engine era of the early 60's- so I wonder if your more modern .40 might not be too much horsepower for this little airplane. I have a couple of OS 20 four strokes that would probably do a good job of fitting in the little airplane, but I would be afraid that their horsepower would not be as high as the .19 minimum recommended by the kit. They were good R/C free flight motors. I do have a couple of OS 32 abc's also but they are screamers and, again, might overpower the airframe.

I have never owned the OS 40 LA, so I am unfamiliar with its performance. But if you intend to use it with a throttle, maybe its operating parameters are within the .19 to .35 engine range recommended by the kit. If it is tight due to the wood construction, maybe you could pull a fiberglass cowl to gain more interior room. Don't give up on it. Good luck.

Jim Fruit

Hi Jim,

Actually it was the only engine here with a carb on it.  I *might* have a Magnum .25 (old style) that will be just right.  The "cowl/engine compartment" is quite cramped when built.  I will probably do something to open it up with out changing the outer dimensions.

I still need to acquire my documentation for painting an details.  With this being my *first* scale entry I will probably mess up a LOT of things! 

Thanks
Bill

HI All,

Jim's mention of a 4S got me to thinking.  For sure the fuel tank will be smaller.

I remember Dick Schnieder (sp) flying a Bipe at Huntersville and it was very "realistic".  The Great Lakes is a 1"-1' scale and am wondering what size 4S would work best....... ??

Thanks
Bill

Bill:

OS has an FS 30 that might be a good match for the model. Four strokes sometimes have larger dimensions because of the exterior valve trains. The 30 is 3.3 inches long to the thrustwasher. I believe the 30 weighs somewhere around 10 ounces. The four strokes inherently turn a lower RPM, but have greater torque -  which allows a larger prop - which allows lower RPM - etc., etc. I am fairly biased about the use of OS four strokes in my scale ships. But, I have had to go to electrics now.

JHF

Hi Bill,

I have started to prod Michael into finishing his Sport Scale Mr. Mulligan. You may remember it was based on a Sterling kit, 1 to 1, 32 inch span. We planned a OS 25, but now it's evident the engine is too heavy for the size and too big displacement wise for the drag of the monoplane as well.

I'm thinking an LA 15 RC would be perfect for the Mr. Mulligan, and I'd figure the bipe with the extra drag on your Great Lakes that an LA 25 would do well. Is the Magnum 25 ball bearing or bushed? I think that these Sterling models are so small, and even building them with the kit wood they come out too light, for a lot of the modern ball bearing engines.

I'm going to keep messing around with this problem myself and see if I'm on the right track on ol' Mr. Mulligan. With a three line deal I'm figuring .012 thou at 52 feet. I'll have to check the rules, there seems to be a minimum line length, and I remember the line size and pull test is about like Jet Speed now.

Chris...