2az-fe article
#1
2az-fe article
Just came accross this....
Tech Briefs
Toyota's new inline four-cylinder engine
The 2AZ-FE VVT-i powers the Japanese Estima minivan and will be Toyota's "core" engine for various mid-size cars, including the company's second-generation gasoline/electric hybrid and the forthcoming Camry replacement.
The 2AZ-FE incorporates Toyota's latest engine technology, including dual overhead camshafts that are driven by a single stage roller chain of 8.0-mm (0.3-in) pitch, enabling a narrow included valve angle and compact combustion chamber shape.
Toyota is accelerating hard on its "core" engine update. Significantly, these engines share the second character "Z," beginning with the type-ZZ that was first adopted in the U.S. Corolla and more recently in the revived mid-engine sports car MR-S. It was followed by the NZ-family propelling various small vehicles, including the Echo sedan.
The Z-gen engine for Toyota's mid-size cars and vehicles is the all-new type-2AZ-FE, making its first appearance in the second-generation Estima minivan (the first-generation Estima was the Previa). The 2.4-L 2AZ will power the next-generation Camry replacement as the base engine and other future mid-size vehicles. The 2AZ-FE incorporates many features of Toyota's dual-overhead-camshaft, four-valves-per-cylinder engines, including the slant-squish combustion chamber, offset cylinder and crank centers, and the VVT-i continuously variable intake valve timing system. The aluminum engine measures 626-mm (25-in) long, 608-mm (24-in) wide, and 681-mm (27-in) tall.
The 2AZ-FE obtains a total displacement of 2362 cm3 with 88.5-mm (3.5-in) bore and 96.0-mm (3.8-in) stroke. The cylinder block is now an open-deck, midi-skirt die-cast aluminum type with cast-in iron liners and a die-cast aluminum lower crankcase and a stamped oil pan. The forged steel crankshaft is fully balanced with eight counterweights and supported by five main bearings. A helical gear pressed in No. 3 counterweight drives twin contra-rotating balance shafts in the shaft housing within the lower crankcase. The balance shaft geartrain includes plastic Nos. 1 and 3 drive gears, meshing with steel gears.
The dual overhead camshafts are driven by a single-stage roller chain of 8.0-mm (0.3-in) pitch, enabling a narrow included valve angle of 27.5°. The camshafts act on four valves per cylinder via bucket tappets. As in the recent Toyota engine practice, no clearance adjusting shim is employed. Valve diameters are 34.0 mm (1.3 in) for intake and 29.5 mm (1.2 in) for exhaust, with 8.0-mm (0.3-in) lift for both intake and exhaust. The four-vane VVT-i device is fitted on the intake camshaft, altering timing by 50°. Fuel is injected sequentially via an ultra-fine-atomization injector with twelve small injection holes, each 0.18 mm (0.01 in) in diameter. As in the smaller NZ engine, the new AZ adopts a plastic, built-up, and vibration-welded intake manifold integrating a large volume plenum chamber (3.5-L (214 in3) volume including a 1.3-L (79 in3) resonator). Twin three-way catalytic converters, each with a 0.84-L (51 in3) volume, are mounted immediately downstream of the stainless tubular exhaust manifold. The front exhaust pipe, collecting from the catalysts, has a separator in the pipe that reduces exhaust gas interference and improves low- and mid-speed torque.
The type 2AZ-FE engine that powers the Estima minivan is rated at 118 kW (160 hp) at 5600 rpm and 221 N•m (163 lb•ft) at 4000 rpm on a 9.6:1 compression ratio, requiring regular-grade, unleaded gasoline. A smaller version of this engine, the type-1AZ 2.0-L unit, powers the recently updated RAV4 light SUV. The Japanese version of this engine, designated 1AZ-FSE, features the fuel-efficient "D4" direct-injection head.
Jack Yamaguchi
AEI July 2000
Toyota's new inline four-cylinder engine
The 2AZ-FE VVT-i powers the Japanese Estima minivan and will be Toyota's "core" engine for various mid-size cars, including the company's second-generation gasoline/electric hybrid and the forthcoming Camry replacement.
The 2AZ-FE incorporates Toyota's latest engine technology, including dual overhead camshafts that are driven by a single stage roller chain of 8.0-mm (0.3-in) pitch, enabling a narrow included valve angle and compact combustion chamber shape.
Toyota is accelerating hard on its "core" engine update. Significantly, these engines share the second character "Z," beginning with the type-ZZ that was first adopted in the U.S. Corolla and more recently in the revived mid-engine sports car MR-S. It was followed by the NZ-family propelling various small vehicles, including the Echo sedan.
The Z-gen engine for Toyota's mid-size cars and vehicles is the all-new type-2AZ-FE, making its first appearance in the second-generation Estima minivan (the first-generation Estima was the Previa). The 2.4-L 2AZ will power the next-generation Camry replacement as the base engine and other future mid-size vehicles. The 2AZ-FE incorporates many features of Toyota's dual-overhead-camshaft, four-valves-per-cylinder engines, including the slant-squish combustion chamber, offset cylinder and crank centers, and the VVT-i continuously variable intake valve timing system. The aluminum engine measures 626-mm (25-in) long, 608-mm (24-in) wide, and 681-mm (27-in) tall.
The 2AZ-FE obtains a total displacement of 2362 cm3 with 88.5-mm (3.5-in) bore and 96.0-mm (3.8-in) stroke. The cylinder block is now an open-deck, midi-skirt die-cast aluminum type with cast-in iron liners and a die-cast aluminum lower crankcase and a stamped oil pan. The forged steel crankshaft is fully balanced with eight counterweights and supported by five main bearings. A helical gear pressed in No. 3 counterweight drives twin contra-rotating balance shafts in the shaft housing within the lower crankcase. The balance shaft geartrain includes plastic Nos. 1 and 3 drive gears, meshing with steel gears.
The dual overhead camshafts are driven by a single-stage roller chain of 8.0-mm (0.3-in) pitch, enabling a narrow included valve angle of 27.5°. The camshafts act on four valves per cylinder via bucket tappets. As in the recent Toyota engine practice, no clearance adjusting shim is employed. Valve diameters are 34.0 mm (1.3 in) for intake and 29.5 mm (1.2 in) for exhaust, with 8.0-mm (0.3-in) lift for both intake and exhaust. The four-vane VVT-i device is fitted on the intake camshaft, altering timing by 50°. Fuel is injected sequentially via an ultra-fine-atomization injector with twelve small injection holes, each 0.18 mm (0.01 in) in diameter. As in the smaller NZ engine, the new AZ adopts a plastic, built-up, and vibration-welded intake manifold integrating a large volume plenum chamber (3.5-L (214 in3) volume including a 1.3-L (79 in3) resonator). Twin three-way catalytic converters, each with a 0.84-L (51 in3) volume, are mounted immediately downstream of the stainless tubular exhaust manifold. The front exhaust pipe, collecting from the catalysts, has a separator in the pipe that reduces exhaust gas interference and improves low- and mid-speed torque.
The type 2AZ-FE engine that powers the Estima minivan is rated at 118 kW (160 hp) at 5600 rpm and 221 N•m (163 lb•ft) at 4000 rpm on a 9.6:1 compression ratio, requiring regular-grade, unleaded gasoline. A smaller version of this engine, the type-1AZ 2.0-L unit, powers the recently updated RAV4 light SUV. The Japanese version of this engine, designated 1AZ-FSE, features the fuel-efficient "D4" direct-injection head.
Jack Yamaguchi
AEI July 2000
#4
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Pretty good, but I don't understand the part about the second letter designation of Z. From my understanding, #_Z-_ _ engines have been around for quite some time.
The 1UZ-FE has been around since 1989 (the 4.0L V8 powerplant of the Lexus LS400, and later the SC400, and GS400. That engine was in production all the way into 2001. And then there's the 2JZ-GE/GTE which everyone knows about. . . and of course it's predecessor, the 1JZ-GE/GTE. So I don't understand what they are trying to convey by "z-gen." The 1JZ outdates the ol Estima motor quite a bit, and even the first gen Previa motors. . .
Please correct me if I am wrong on my engine history.
The 1UZ-FE has been around since 1989 (the 4.0L V8 powerplant of the Lexus LS400, and later the SC400, and GS400. That engine was in production all the way into 2001. And then there's the 2JZ-GE/GTE which everyone knows about. . . and of course it's predecessor, the 1JZ-GE/GTE. So I don't understand what they are trying to convey by "z-gen." The 1JZ outdates the ol Estima motor quite a bit, and even the first gen Previa motors. . .
Please correct me if I am wrong on my engine history.
#5
There was already an "A" engine series (for example 4A-GE, 4A-FE ( http://en.wikipedia.org/wiki/Toyota_A_engine ). So to seperate out this new "A" engine family (VVT-i) Toyota placed a "Z" after the letter. I think the "AZ" family is aluminum while the original "A" was made out of cast iron.
#6
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Posts: 4,322
Yeah. . . it seems the article focuses on the Z label, and it's nothing new. . . or so I thought. They were grouping the AZ series with the NZ and ZZ.
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