DS-125cc fourstroke rotary valve engine
Rotary valve engine Original DOHC-engine
Weight savings: 2,5 Kg Package savings: 80 mm
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Targets for the application of the rotary valve train on the 125cc motorcycle engine
- Demonstration of the package and weight benefits
- Increase of maximum torque and reduction of fuel consumption by high compression ratio and decrease of friction losses
- De-throttling at part load by high exhaust gas reduction (EGR)
- Perpetuation of original carburator and silencer equipment
- Reduction of engine noise emissions
Results of the rotary valve train on the 125cc motorcycle engine
- The engine dimensions of the cylinder head had been reduced significantly. Weight savings of 2,5 Kg and height savings of 80mm had been realized.
- The peak performance had been achieved in combination with a much improved torque characteristic (see figure-performance diagram)
- A high compression ratio of 14:1 without knocking phenomena had been realized
- The engine had been de-throttled essential by EGR
- During the field tests the fuel consumption had been reduced from 3,2 L/100km (original engine) to 2,8 L/100km for the rotary valve engine
- The noise emission at near sound field had been decreased for 2 dBA