Note, the FW-K45 engines are not produced in "big" volumes - it's a small scale production for EXPERTS ONLY. The engine might need some final touches with your Dremel etc. If you are a "sport" boater - look elsewhere - this is NOT the engine for you!
My own reflections:
The characteristics of the short-stroke K45 is that it wants to rev higher then most long-stroke engines. That means that the pure torque is in most applications less then other similar longer stroked engines. In reality that means that the heavier, and more "wet", your boat is - the smaller propeller you need to use. If you think that you can tune the K45 in the same way using the same prop as another race engine you will most likely be disappointed.
The lighter-weight, and lighter running, modern 3-point outrigger hydroplanes are the ones that are the easiest to get running really good with the K45 if you ask me. If you have an "old-school" (wet-running) and heavier 4/5-point hydro like an Eagle, RoadRunner or FireFighter etc - then the performance difference might be smaller and you need to use a smaller prop. On my prototype KEP's T2-44 rigger I can use the same prop as with the engine I have been racing with in 2013 though but it's about 10% faster - mostly due to the fact that I can lean it in so it revs more.
- Direct Drive Hydro Version: With separate front box. Flywheel included. Price: 380€
- Geared Version (no picture of this motor): With solid casted crankcase (no separate front box). To be used with a gear box and the crankshaft pointing forward in the boat (FSR-V & FSR-O boats). Price: 350€
- 7.45 ccm
- 3-port ABC liner with single exhaust
- Stroke: 19.6 mm
- Bore: 22.0 mm
- Flat-top billet machined piston
- Glowplug thread: conical/turbo
- H-beam steel con-rod with free-floating needle bearing lower end (no roller bearing cage holder)
- Central induction drum intake system with CNC:ed aluminum intake case with bronze bushing for the drum
- Carb with 9.8 mm venturi and built in metering system (can be modified for those who wants no "midrange" metering). Note, the carb barrel is "directional" as it has a metering system built in!
- Crankshaft threads: M8
- NR46 manifolds and exhaust seals have been used in testing
- Outrigger hydro: 40-60% Nitro with 8% recin & 8% synthetic oil = 16% total oil content (preferably Klotz Benol & Klotz Original Techniplate oils)