Ad
related to: camshaft valve timing calculator set up video clips 2 pack
Search results
Results From The WOW.Com Content Network
The valve timing of a diesel engine also depends on tappet clearance of the inlet and exhaust valves. If tappet clearance is less, then valve will open early and close late. [2] If tappet clearance is more, then valve will open late and close early. Tappet clearance is measured by an instrument called feeler gauge.
For twin-cam or DOHC engines, VCT was used on either the intake or exhaust camshaft. (Engines that have VCT on both camshafts are now designated as Ti-VCT.↓) The use of variable camshaft timing on the exhaust camshaft is for improved emissions, and vehicles with VCT on the exhaust camshaft do not require exhaust gas recirculation (EGR) as retarding the exhaust cam timing achieves the same ...
VarioCam varies the timing of the intake valves by adjusting the tension on the timing chain connecting the intake and exhaust camshafts. VarioCam was first used on the 1992 3.0 L engine in the Porsche 968. Porsche's more recent VarioCam Plus combines variable valve timing with two-stage lift on the intake side. The two-stage valve-lift ...
Early variable valve timing systems used discrete (stepped) adjustment. For example, one timing would be used below 3500 rpm and another used above 3500 rpm. More advanced variable valve timing systems offer continuous (infinite) adjustment of the valve timing. Therefore, the timing can be optimized to suit all engine speeds and conditions. [2] [3]
This mechanism can accelerate and decelerate the rotational speed of the camshaft during different parts of its cycle. e.g. to produce longer opening duration, it slows the rotation during the valve open part of the cycle and speeds it up during the valve closed period.
N-VTC varies valve timing by rotating the affected camshaft relative to the sprocket; valve lift and duration are not altered. This rotation is achieved when an electric solenoid, controlled by the car's ECU, allows pressurized engine oil to flow into and through the cam and into a slave mechanism, axially advancing camshaft timing relative to ...
The inlet camshaft position is advanced 25 degrees, thus increasing valve overlap. It remains in this advanced state until about 5000 rpm when the solenoid switches off, and the variator piston returns the valve timing to its natural state. The variable timing increases the engine's mid-range flexibility and reduces emissions.
Cutaway of a dual overhead camshaft engine 1969 AMC V8 overhead valve engine. The rocker cover has been removed, so elements of the pushrods, rocker arms, valve springs, and valves are visible. A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. [1]