We attended the Arctic Cat presser last week and spent quality time talking engines with the Cat Crew. Specifically, we talked about the highly anticipated 794cc C-TEC2-800 powerplant for 2018. Before we dive into some of the more interesting details, we should say that the goal for the project are lofty: more power, reduced emissions, ultra-low oil consumption and increased durability all while delivering overall crispness and rideability. Here’s how they attacked the challenge…
1. 3-stage exhaust valves
- Arctic Cat’s new 8000 series engine uses a unique three-stage, three-piece Arctic Power Valve system. The computer-controlled APV uses a traditional-style guillotine valve on the primary exhaust port, but uses a pair of separate, circular side valves to control the auxiliary ports. The functional goal of the exhaust valve system remains the same: flow big air at high RPM for maximum power, but close off the auxiliary ports at low engine RPM to maintain throttle response and performance at lower speed. The new APV calculates optimum position by pulling data from Cat’s unique pipe temp sensor, engine speed sensor and barometric pressure sensor.
- An added benefit to the new valve system is an automatic decompression system to assist pulling the engine over first thing in the morning. The valves assume the open position when the engine is shut off to reduce engine compression, cycling through their stoke once the engine is running.
2. Fuel rail damping system
- The new CTEC-2 800 engine uses a unique fuel rail damper to absorb the minute impulses created when the injectors fire. Cat engine engineer Don Eide explained that the damper helps control fuel pressure in the rail, allowing his team to produce very consistent calibration and performance.
3. Air-only intakes
- The new 8000 series Arctic Cat engine boasts 50mm throttle bodies to flow massive amounts of air into the crankcase. Not only are the new throttle bodies larger in diameter, but they are shorter, to deliver extra-sharp throttle response.
4. 4-petal reed valves
- Arctic’s engine development team mated new 4-petal reeds to the new big-bore throttle bodies. The W-shaped design flows air smoothly and sharply to the crankcase.
5. CTEC-2 600 Heritage
- There is clearly a lot of engineering that carries over from the CTEC-2 600 engine to the 800. It only makes sense, right? Among the 6000-class engine innovations that we found on the big brother…
- Slotted piston design: facilitates the dual-stage fuel injection system’s delivery to the crankcase. Friction reduction coating also helps durability.
- Dual-stage fuel injectors: fires fuel above and below the piston crown, depending on what the onboard computer says the engine demands. Your benefit is optimized engine performance, durability and fuel/oil economy.
- The new CTEC-2 800 engine uses an electronically controlled oil pump to ensure engine durability while reducing oil consumption. How does it do that? The system uses strategically located oil injectors at the air intake flanges and fuel injectors. In concert with the dual-stage fuel injection system and the slotted piston design, the new oilers meter oil flow to keep piston, piston pin bearing, and the crank lubricated according to engine demands.
- Laydown design: really this is a hallmark of Cat 2-stroke engines since the good ol’ Firecat days. Air in, exhaust out on the front side, with fuel rail on the back. It lets chassis engineers put the engine in deep, for great handling.
- Knock sensor: keeps your engine safe from detonation damage due to poor fuel by adjusting engine timing and fuel delivery.
- Engine temp sensor: feeds data to the control unit to keep your engine running at optimum performance.
6. Redesigned recoil
- Cat engineers redesigned the recoil and housing to reduce weight and move heat. They also engaged and anti-kickback cap on the recoil to prevent you from getting snapped.
7. It delivers on the promise
- We had a chance to try the new engine, albeit briefly, last week at Arctic Cat’s sneak peek. In that short ride, we were able to blip and blast around an icy closed course, so there wasn’t a good opportunity to really let it stretch its legs, but we were able to glean a few impressions.
- First, the throttle pull is super light. That delivers a couple things: it doesn’t cramp your thumb and it makes the whole sled feel light and agile. If you can modulate the throttle easily, you feel more like the sled is a part of you.
- Second impression is that the engine is crisp and responsive. This is not a slow-to-power big bore engine. It revs quickly, puts the torque to the snow and exits a corner exactly when you think it.
You will find the new engine in the just-released 2018 ZR8000 129” and 137” and the just-released M8000 153” and 162” sleds. More on those tomorrow!