User:Ridge Runner/Sandbox/drafts

The 2ZZ-GE is a 1796 cc inline-4 engine manufactured by Toyota. Built in Japan, it's designed to fit into the same space as a 1ZZ-FE, the size and displacement of the engines are where most of the similarities end. Instead of having an iron cylinder wall like most engines, the 2ZZ uses a metal matrix composite (MMC) to help prevent cylinder wear and achieve a linerless construction. The downside of using this technology is that if the engine is bored, the MMC is worn away and an iron sleeve must be pressed into the bore. Otherwise, the up and down motion of the pistons, combined with the high rpms of the engine, would quickly wear away the soft aluminum that the block is made from.

Another unique feature of the 2ZZ is its ability to not only alter its valve timing - a fairly common feature in modern vehicles, but also change how far the valves open. Called Variable Valve Timing & Lift - intelligence, this process achieves similar results to i-VTEC, but by a different means.

Designed from the start as a TLEV engine, later model Matrix and Corolla engines were equipped with smog pumps and reprogrammed PCMs, making them Ultra Low Emission Vehicles, or ULEVs.



The 2ZZ-GE is a Toyota 1.8 L (1796 cc or 109.6 in³) engine built in Japan.

Bore is 82 mm (3.23") and the stroke is 85 mm (3.35"). It uses MFI fuel injection, has VVTL-i, and features forged steel connecting rods. Compression ratio is 11.5:1, necessitating "premium" gasoline (91 octane or above in the (R+M)/2 scale used in North America ). Power output for this engine varies depending on the vehicle and tuning, with the Toyota Celica, Toyota Corolla T-Sport, Lotus Elise and Lotus Exige offering 141 kW but the American versions of the 2003 Toyota Corolla, Toyota Matrix, and Pontiac Vibe versions only developing 180 hp with all later years offering anywhere from 173 hp in 2004 to 164 hp in 2006 due to a recurved powerband. The differing power numbers from 2004 through 2006 are due to changes in dynamometer testing procedures. The Australian variant Corolla Sportivo is 141 kW@7600 and 181N·m Torque due to noise regulations. (Toyota recalled them for a flash of the PCM to up their output to classify them in the more lenient "sports car" noise category.) The Corolla Compressor and Lotus Exige S add a supercharger to achieve 225 hp, while the Exige 240R's supercharger increases output to 240 hp.

Unique to the ZZ family, the 2ZZ-GE utilizes a dual camshaft profile system (the "L" in VVTL-i, known by enthusiasts as "lift") to produce the added power without an increase in displacement or forced induction. The table below lists the specifications of the camshafts. This is similar in concept to Honda's i-VTEC, but the two systems are very different in design and execution.

Excluding the 2003 MR2, the engine is also the only model in the ZZ engine family to use a six-speed manual transmission, as well as the only one to have been available with a four-speed Tiptronic-style automatic. These gearboxes were unique to this engine; since then, only a few Toyota engines have been paired with either a six-speed manual or a Tiptronic-style automatic (and only one other engine, the 4GR-FSE, has received both).

Toyota commissioned Yamaha to design the 2ZZ-GE and it shares several similarities with street bike engines, the most notable being the relatively high RPM design. The high-output cam profile is not activated until approximately 6,200 rpm (the exact point of engagement is different depending on the vehicle, year, and PCM involved) and will not engage until the engine is sufficiently warmed up. The Toyota PCM electronically limits RPM to about 8200 RPM (or 8400 RPM in some earlier cars) via fuel and/or spark cut. Consequently, it's impossible to "over-rev" the engine with the throttle alone; a downshift from a higher gear must be involved. A typical "over-rev" can damage the oil pump, commonly disintegrating the lobe ring, resulting in damage similar to the picture at right. The oil pump is the Achilles heel of the 2ZZ, though incidents are rare and usually occur due to fault of the driver. Unfortunately, starving this particular design of oil is almost always fatal to the engine, even when caught quickly.

The engine will easily run at speeds of around 4,000 rpm for extended periods of time and is designed to periodically run at the 8,400 RPM redline without issue. For the first few years of production, the engines were notorious for failing "lift bolts". This didn't damage the engine, but would hamper performance, as the high output cam profile was unable to properly engage. Toyota fixed the problem in late 2002 with a redesigned bolt that was installed on later engines. Earlier engines with the problematic bolts can be fixed via a Toyota-issued TSB simply requiring the new bolt to be installed in place of the old one.

Also, 2004 and newer Matrix and Corolla XRSes were sold with smog pumps and have an extra hole in the engine block and header where the "air" is extracted for induction into the intake.