No-Smoke Two-Stroke


Goals and Deliverables


Goal:  Develop a direct injection 2-stroke snowmobile engine. Purchase or design and manufacture all components for this system.  The engine is to be fuel-efficient and have limited exhaust emissions while conforming to the rules set by the SAE Clean Snowmobile Competition.




1) Operational- The engine must run.  It must be able to start and idle as well as run in all rpm and power combinations.


2) Tunable and Controllable- The engine management system must be able to adapt the engine to run well in varying altitudes and temperatures.


3) Manufacturability- The engine will be easily reproducible with a combination of “off the shelf” and machined components. 


4) Robust- The engine and all of its components must be able to withstand the extreme rider requirements and the very brutal testing the engine will undergo.


Constraints:  To be acceptable the engine must satisfy three requirements.


1) The engine configuration must follow the rules of the SAE 2004 Clean Snowmobile Competition.


2) The engine must be able to score more points based on the competition-scoring scheme than the BMW K75 four-stroke engine used in previous competitions.


3) The engine and all its components must cost no more than $4000.


Outcomes:  At the end of the project, we will deliver:


1) A running, low emission, and fuel efficient two-stroke engine.  Metrics:  (a) Measurement of the engines ability to perform will be tested using the engine dynamometer, fuel flow meter, and emissions analyzer.  Our target is to have more horsepower and torque as well as better brake-specific fuel consumption and lower brake-specific emissions than the BMW K75 engine.  (b) Measurement of engines ability to withstand extreme use will be tested using the dynamometer in simulated engine performance tests as well as actual snowmobile excursions to test full system reliability.


2) A final report that is well organized and complete.  This report will include (i) detailed drawings of designed and fabricated components as well as system design and operation, (ii) a description of the engineering decision process followed to reach our design goal, (iii) and the final testing results of our engine and fuel induction management system.