Is there a SOHC VTEC?
SOHC VTEC is a power implementation of VTEC for SOHC engines with the express intention of extracting high specific output. This is the reason why Honda implemented VTEC on the intake valves only. SOHC VTEC engines are high specific output forms of the standard SOHC engines.
What does SOHC VTEC mean?
SOHC – Single Over Head Cam Shaft a design in which one camshaft is placed within the cylinder head. VTEC stands for Variable Valve Timing and Lift Electronic Control and represents a variable valve control system developed by Japanese Honda for its gasoline engines.
How does the camshaft work in a Honda VTEC?
In the traditional engine, the camshaft controls valve opening and closing, and its lobes are all the same size. In Honda’s VTEC engine, as you saw in the video, the camshaft has two different types of lobe sizes: Two standard-sized outer lobes and a larger center lobe.
How does the VTEC switch from low lift to high lift?
The switching operation between the two cam lobes is controlled by the ECU which takes account of engine oil pressure, engine temperature, vehicle speed, engine speed and throttle position. Using these inputs, the ECU is programmed to switch from the low lift to the high lift cam lobes when certain conditions are met.
Where is the camshaft located in a Honda engine?
In an engine, the camshaft is a long rod that normally sits above the cylinder and the piston, and that operates the valves which plug up both an intake channel and an exhaust channel. One rotation opens the intake channel, allowing fuel and air into your engine’s cylinders.
What kind of valve timing does a VTEC engine use?
The VTEC system provides the engine with valve timing optimized for both low and high RPM operations. In basic form, the single cam lobe and follower/rocker arm of a conventional engine is replaced with a locking multi-part rocker arm and two cam profiles: one optimized for low-RPM stability and fuel efficiency,…
How many valves does a Honda F23 VTEC have?
It used a single-overhead cam (SOHC) configuration and electronic fuel injection to funnel fuel through four valves per cylinder, for a total of 16 valves. The F23 VTEC had a bore of 86 mm and a stroke of 97 mm. Honda installed the F23 VTEC into two of its cars: the Honda Accord and the Acura 2.3 CL.
How does the Honda VTEC engine timing system work?
A third option is to change the cam timing profile, of which Honda VTEC was the first successful commercial design for altering the profile in real-time. The VTEC system provides the engine with valve timing optimized for both low and high RPM operations.
The switching operation between the two cam lobes is controlled by the ECU which takes account of engine oil pressure, engine temperature, vehicle speed, engine speed and throttle position. Using these inputs, the ECU is programmed to switch from the low lift to the high lift cam lobes when certain conditions are met.
Where is the VTEC switch located on a Honda engine?
The intake and exhaust rocker shafts contain primary and secondary intake and exhaust rocker arms, respectively. The primary rocker arm contains the VTEC switching piston, while the secondary rocker arm contains the return spring. The term “primary” does not refer to which rocker arm forces the valve down during low-RPM engine operation.