OK, time to chime in here. First of all, YES, it IS running Jan Carlsson. I first ran the prototype on April 16th, 2014, then many times for the crowd at AirVenture 2014 and now hundreds of times for initial testing. The videos on the website should show that.
About the expected power. I agree that the O-200 is less than 100 hp. Continental themselves rate it at 98HP @ 2750. I wrote about my estimations of power a while back on this thread but, before I review that info, let me say that my test stand is undergoing a mod as we speak that will give real-time torque values on the instrument panel thereby eliminating all the guessing. I will post video of that when I get it finished. So Jan, the way I calculated it initially was to compare the factory reported HP/RPM ratings for the following engines: A-65, O-200, O-235, O-320, O-360. O-540. By backing those numbers through the torque formula, T= 5252HP/N and dividing T by the displacement I found that the values ran between .87 and 1.2 ft.lbs/cu.in. The biggest factor on raising the value seems to be the compression ratio; i.e. The higher the compression ration the more ft.lbs./cu.in. the engines had. By plotting these known values against their respective compression ratios, I found that engines with 9:1 compression have values of approximately 1.05 ft.lbs./cu.in. So in estimating what we might see for HP on the O-100: 105 x 2900/5252= 57.9 HP. I would not be surprised to find that the engine, as it sits, is only making 50HP right now but ONLY because I know I don't have an ideal carb and mixture. The Marvel-Schebler MA-2 is VASTLY better than the Zenith but the engine is still running rich.
Let's all reserve the HP opinions until the dyno gives me some accurate torque readings (that goes for me too). I'll put N/A on the website until I get the dyno built. Jan, I agree with you that fuel injection/electronic ignition might help a ton in the future but my main focus right now is to get the production kits up and running in beta testing and find a readily available aircraft carburetor that will work well. I would be surprised if we can't get it up to 58-60 horse with a little tweaking and continued R&D on this otherwise mechanically sound platform. Thank you for your input.
You simultaneously lose half the gross HP. There's no gain here. It's a wash, or slightly worse.When you cut an O-200 in half, you reduce the cylinder friction by half...remove some main bearings and cam bearings, and reduce the loads on the gears and cam lobes and valve train significantly. And the windage loss, and the mass oil flow/return.
So if the O-200 really only makes 81 HP......this engine makes 57-58HP by the same method of estimation as an O-200 makes 100 HP...
That person was me, and yes, the airplane did not at all behave as if it were underpowered. The CrackerJack is an all-wood-frame-and-fabric LSA-type single-seater. I don't know the weights either, but it's no ultralight by any means. I've seen airplanes in the same overall weight class fly with 4-cyl VW engines in the 60-65hp power class quite a few times, and the CrackerJack with the pre-production O-100 seemed, if anything, more "sprightly" than those airplanes. Climb-out was steady and strong, even on a rather warm day. I'm sure the fact that it turns a larger prop, more slowly, than those VW conversions has much to do with the performance.... At least one [other] HBA forum member was there on that day as well, and I believe that person would agree that the O-100 engine provided very reasonable and sufficient power for that aircraft. And that was with a less than optimized carburetor and intake system compared to the production version.