I wote the guys @ Replika Maschinen, Inc... THe builders of the 100 ft. lb. CR500 motor... and asked them the following questions...
"Don, thank you for your time...
I'm interested in the CR500 engine you built, with 100 ft. lbs torque. I'm a professional hillclimber, and could use such a engine.
You state that it uses allot of stock components and compression ratio. I'm curious how you achieved doubling the output of this engine, it surely cant be through porting alone? The jug I saw looked stock, with no external welding of the transfer port passages....
Do you know the MEP for this level of performance?
Will I need aftermarket ignition?
This was on gasoline..corrrect?
What else is needed, besides the engine rework?
Carb?
Pipe?
Do you have a dyno sheet available, so I can determine the gearing I will need to tun?
I would like a price, and delivery date for such an engine, I have a few events left this season, and would like to run this engine combination at them.
Thanks again
Bob"
Here is the response I received...
"Torque is an indicator of volumetric efficiency, we efficiently filled the cylinder and that in turn produced a lot of lower RPM power. As we changed things, carb size, pipe, etc the power band moved up a bit, RPM increased and power out put changed. What has alway been notable about the RMI Stage II is that it is user friendly until it really get into its power band and then it will pull your arms off. It is still very tractable and has a flat torque curve, it is not peaky. If I remember correctly the gearing is 15/43 not positive right now. With that at Pismo Beach we only had problems with Suzuki 1100 hot rodded engined Quads with big paddle tires, we ran them even. Stock everything except we installed a paddle tire as well. It did out run pro level drag sand rails.
Our RMI Stage I engines are similar just with less power and this is what we suggest of our MX or trail riding customers. Again very tractable, throttle response is improved and controllable.
Yes we can build you a very strong engine. I always tell customers that the stronger their arm and upper body strength is the better. They always think I am full of shit until they get the engines and ride the bike. There is a big difference between a very strong and wide power band engine and the usual high revving peaky two strokes.
There are a couple of things that I would like to do to the engine that I feel would improve power out put. So yes there is room for more. I am working on a CR-500 engine project for a Bonneville record attempt so this could be quite advantages for both of you. Being able to work on two all out project would greatly enhance my ability to develop some interesting pieces.
Don Redmon
RMI"
It dosent contain answers to most of my questions, and suggests that a even more powerful engine is available , beyond the 100 ft.lb / 98hp level.
No dyno chart was memtioned, or supplied.
I guess we will have to wait to see how it performs at Bonneville, but that is WAY more about streamlining and mechanical efficiency, and not about horsepower...
We'll see.....
On the web......
http://www.replikamaschinen.com
Any of you REAL Hillclimbers want to take this guy up on his offer to develop his ideas into real hardware?
...........might be interesting