1. Heads Under Pressure Nick Harker Chris Tockey Peter Britanyak Design Project: Instrumented Head for the Clean Snowmobile Challenge

2. Project Goals: Head Re-designed with pressure sensors for in-cylinder pressure data. Modify the combustion chamber to given specs.

3. Combustion Chamber dimensions and Specs Dome radius.75 inches Cone to plug distance is -.08 inches Squish velocity of 15-20 m/s Squish diameter of 1.95 inches Squish radius from cone to squish.25 inches (double turbo head) No dome offset Squish area same as turbo head 34% Dome height approx. 1 inch as necessary for compression ratio Dome angle needs to be determined for the correct compression ratio Compression ratio of 6.5:1

4. Design comparison 2004 to 2006 Parameter2004 Design2006 designWhy? Injector Angle115 Injector aimed toward intake to inhibit unburnt fuel leaving though intake port. Squish Diameter1.751.81Increased for efficiency. Squish Area %41%39.50%Similar to last design. Dome Offset.05"0Centralized dome allows centralized combustion. Dome Height1.251.06Decreased with increase in dome height. Dome Angle59.559.64Similar to last design. Dome Radius0.40.7Better nozzle geometry for symmetrical fuel cone. Squish Radius0.040.25Increases work done on piston. Plug Distance from Top of Chamber 0.650.47 Designed for sparkplug to be half the distance from the injector to bottom. Sparkplug to Fuel Cone Distance -0.080.02 The increase in dome radius moved the sparkplug out. The grounding strap is in the fuel cone and the electrode is.02 from the fuel cone. Compression Ratio66.5Staying with stock compression ratio. Combustion Chamber volume 33cc26ccMust be the same to conserve compression ratio

5. Combustion Chamber Iterations Drawing showing the location of a regular and extended electrode Sparkplug boss protruding into combustion chamber Final iterations of unsymmetrical combustion chambers to bring the sparkplug electrode into the fuel cone

6. Final Design for Polaris 600

7. Injector and Sensor Boss Injector and sensor boss passes through the cap to reduce the over all height.

8. Skidoo 600 Head Design Skidoo sled will be much easier to adapt to our system

9. Skidoo Head Skidoo Combustion Chamber Polaris Combustion Chamber

10. Water Jacket Comparison Skidoo HeadPolaris Head

11. Current Progress Head designed Aluminum stock arrived Received Kistler pressure sensor tools Received ARP head bolts and gasket material

12. Current Tasks Get solid model approved for manufacture Sept. 19 Complete MasterCam Oct. 9 Begin machining Oct. 11 Testing End of Oct.