E-TEC, SDI and P-TEK

Dear Ralph:
I know you can help me. I know what SDI and E-TEC is, but what is Power “T.E.K.” on the 800R? Of course, this is Ski-Doo. My most important question is: What is it with the domed heads on the 2012 600 carb engine? All my previous engines (DPM, SDI and Carb) had flat heads. I keep your magazines for years. Did I miss something along the way?

Richard Hunt
Montague, Michigan

A Power TEK engine has carburetors, but has an auto-compensating system and is able to run with proper calibration across a very wide range of conditions. Power TEK is an active system monitoring operating conditions and varying fuel delivery via float bowl pressure regulation.
The Power TEK (and DPM) are active carb systems, with varying air pressure being applied to the float bowl, which in turn varies the fuel delivery. Typically the float bowl is at atmospheric pressure, so by controlling the bowl pressure we can increase or decrease the overall fuel delivery. The Power TEK was the most advanced of these systems, which started as simple mechanical pressure devices (HAC – high altitude compensator) and evolved into active electronic systems, monitoring ambient temperature, barometric pressure, engine rpm and rate of increase or decrease, engine coolant temperature, and possibly an exhaust temperature input as well. Very much like EFI, but controlling the float bowl pressure instead of injector timing and duration. It works very well, and is often called the “poor man’s EFI” as it provides the same auto-adjust capability but is priced at a discount in comparison.
Domed heads on the 2012 carbed 600 engine – you are correct, the 2012 version of the carbed 600 engine has a different cylinder head. It is very similar in design to the head that was developed for the 600 E-TEC engine, sort of a case of applying new technology to existing platforms. This new cast one piece design improves cooling efficiency, reduces combustion chamber temperatures, increases strength and reduces coolant leak potential. That should also mean reduced possibility of detonation, as well.