How do engines shut down cylinders?
How do engines shut down cylinders?
When a cylinder deactivates, the system closes its intake valves, which draw in air, and its exhaust valves, which release spent gases. It also stops injecting fuel into the cylinder. The piston still moves up and down – it has to, because it’s attached to the spinning crankshaft – but now it’s just along for the ride.
What is cylinder shut off?
When an engine fitted with cylinder deactivation detects the car is cruising, a solenoid valve opens and a system forces the valves shut, preventing fuel and air from reaching some of the cylinders. This means combustion is only taking place in half of the engine and thus much less fuel is burned when cruising.
How does Honda’s Variable Cylinder Management System work?
Unlike the pushrod systems used by DaimlerChrysler ‘s Multi-Displacement System and General Motors ‘ Active Fuel Management, Honda’s VCM uses overhead cams. A solenoid unlocks the cam followers on one bank from their respective rockers, so the cam follower floats freely while the valve springs keep the valves closed.
How does cylinder deactivation work in a V8 engine?
Deactivation is mostly used on V6 or V8 engines, where, in principle, it reduces the engine’s displacement when it functions: Bigger-engine power when all cylinders are activated, and smaller-engine fuel economy when some are shut off.
What happens when you switch from V8 to V4?
During the transition from V8 to V4 mode, the ECM turns the fuel injectors OFF on the deactivated cylinders. However, the ignition system still provides high secondary voltage to the spark plugs and the spark still jumps the gap on the deactivated cylinders.
What to do when VCM system disables cylinders?
When the VCM system disables cylinders, an “ECO” indicator lights on the dashboard, Active Noise Cancellation (ANC) pumps an opposite-phase sound through the audio speakers to reduce cabin noise, and Active Control Engine Mount (ACM) systems reduce vibration.
During the transition from V8 to V4 mode, the ECM turns the fuel injectors OFF on the deactivated cylinders. However, the ignition system still provides high secondary voltage to the spark plugs and the spark still jumps the gap on the deactivated cylinders.
What does Variable Cylinder Management do on a Honda truck?
Honda’s system, which it calls Variable Cylinder Management, can switch a V6 engine to run on three or four cylinders, depending on what’s best for the driving conditions. General Motors, which currently shuts off half the cylinders on its pickup truck engines, will introduce a variable system on its 2019 trucks.
Deactivation is mostly used on V6 or V8 engines, where, in principle, it reduces the engine’s displacement when it functions: Bigger-engine power when all cylinders are activated, and smaller-engine fuel economy when some are shut off.
What’s the problem with a V-4 engine?
The problem is that a V-4 is very complicated. Like any V engine, a V-4 needs two cylinder heads, two exhaust manifolds, two valvetrains, and twice as many camshafts as an inline-four. That means a V-4 is expensive to develop and expensive to build.
