vtec?

[bombadill]

Ok I'm confused. I'm new to hondas but I'm trying to learn. I just bought a 93 delsol with a D16z6 engine. I was reading a book and saw that the d16z6 was a vtec. Is it? If so is it any different then the newer vtecs?

[94civic]

yes the d16z6 is vtec. and when you mean newer vtec engines what kind dohc or sohc and what years.

[jcrx]

There is vtec, vtec-e, and vtec-i, the latter two are emissions friendly, and the first is more performance oriantated. The first Honda to use vtec was the 89 NSX and since then it has been in several, including the civic, delsol, CRX, prelude, shuttle, integra, and a couple more.

[bombadill]

thanks alot. that helps me out more then you can imagine.

[Drifter To Be]

Originally posted by jcrx
There is vtec, vtec-e, and vtec-i, the latter two are emissions friendly, and the first is more performance oriantated. The first Honda to use vtec was the 89 NSX and since then it has been in several, including the civic, delsol, CRX, prelude, shuttle, integra, and a couple more.

I thought i-VTEC was even more towards performance than VTEC as well as emissions.
Isn't i-VTEC just VTEC with VTC?
And if it is... I thought that VTC helps with performance as well as emissions.

[mrsyeltzin]

whats vtc?

[jcrx]

The i-VTEC system (the “i” stands for “intelligent”) combines Honda’s patented VTEC system (Variable Valve Timing and lift Electronic Control) with Honda’s cam position-adjusting VTC system (Variable Timing Control) to enhance low RPM torque while extending high RPM horsepower. This potent system gives the engine a broad torque curve that starts early at low RPMs, similar to a larger displacement engine with more cylinders, while still delivering high revving horsepower. Most modern engine designs produce either high horsepower and low torque or low horsepower and high torque, or a bland variation of the two. Honda’s i-VTEC-equipped engines solve this dilemma, delivering both high horsepower and high torque. The combination of conventional VTEC technology with VTC provides the engine with strong low- and mid-range punch as well as a robust high end by adjusting the opening and closing of cylinder head valves while the engine is operating. To accomplish this, the i-VTEC “intelligent” valve timing system adjusts and optimizes camshaft duration (VTEC) and timing (VTC) as the engine transitions from low-speed to high-speed operation. Controlled via a computer and hydraulically activated, i-VTEC constantly evaluates engine load, rpm, throttle position and other factors to adjust the phase and duration of the camshaft. Element’s i-VTEC systems operate with a two-rocker configuration on the intake camshaft. The exhaust camshaft is not i-VTEC-controlled.

Another benefit of VTC is the internal exhaust gas recirculation (EGR) effect created by the valve overlap. Internal EGR reduces pumping losses and eliminates the need for a separate EGR valve. The i-VTEC cylinder head is made of pressure cast aluminum alloy. Its four-valve per cylinder design has double overhead camshafts activated by a silent chain drive to ensure extremely precise control of the cam phasing. The VTEC system is comprised of the following primary components: VTEC rocker arm, VTEC spool valve and computer controlled VTEC hydraulic actuator. Similarly, the VTC system is comprised of the following primary components: computer-controlled VTC hydraulic actuator, VTC spool valve and cam sensor. Depending on conditions, VTC can vary the phasing of the intake cam (change its position relative to the crankshaft) by +/- 25 degrees in infinite increments. VTC activation is accomplished hydraulically via a spool valve that sends high-pressure oil to passages in an actuator located in the cam’s drive sprocket.

[crxlvr]

very nice post jcrx, very informative

[nickzed20]