Engines and Transfer Cases
Chevy Avalanche 5.3L V-8
The Chevrolet Avalanche is powered by the Vortec 5300 V-8. Measuring in at 5.3 liters, or 327ci, the Vortec uses a bore and stroke of 3.78x3.62 to develop 285 horsepower at 5,200 rpm and 325 lb-ft or torque at 4,000 rpm. The block is constructed of iron. Aluminum heads with two valves per cylinder top it off. Compression ratio is 9.5:1, and fuel is fed into the combustion chambers by a sequential electronic fuel-injection system.
The Avalanche uses a New Venture 246 transfer case. This uses an aluminum case and features a low-range of 2.72:1. A unique feature of the 246 is Autotrac, a system that, when selected, keeps the truck in two-wheel-drive until tire slippage is sensed. When that happens, the system transfers power to the front axles until traction is restored.
Dodge Ram 4.7L V-8
Our Dodge Ram 1500 test vehicle appeared in our parking lot wearing a 4.7L (287ci) engine that produces 240 horsepower at 3,200 rpm and 300 lb-ft of torque at 3,200 rpm. The block of this engine is made of cast iron and features a bore of 3.66 inches and a stroke of 3.40 inches. On top of the block sit aluminum heads that feature a total of 16 valves controlled by a single overhead cam for each head.
Splitting the power front to rear on our Dodge Ram 1500 is a New Venture 241 transfer case. Made with an aluminum case, it is chain-driven and features low-range gearing of 2.72:1. A manual shifter controls this easy-to-shift transfer case, a feature that was appreciated by our testers.
Ford F-150 5.4L V-8
We found the biggest engine of our bunch this year under the hood of the Ford F-150. Measuring in at 5.4 liters (330 ci), the Triton V-8 produces 260 horsepower at 4,500 rpm and 350 lb-ft of torque at a nice-and-low 2,500 rpm. Other specs include a 3.55x4.16 bore-and-stroke and a compression ratio of 9.0:1. The valvetrain is composed of single overhead cams controlling two valves per cylinder. A sequential multi-port electronic fuel-injection system supplies the fuel.
A Borg-Warner 44-06 transfer case sends power to both axles. This aluminum transfer case is part-time, and is chain-driven. Low-range for the 44-06 is a respectable 2.64:1 and our test vehicle featured an electronic shifter.
Nissan Frontier 3.3L V-6
Powering our Nissan Frontier was the optional supercharged 3.3L V-6 engine. It uses an Eaton M62 Roots-type supercharger that delivers a maximum of 7.5 pounds of manifold pressure to boost output to 210 horsepower at 4,800 rpm and 246 lb-ft of torque at 2,800 rpm. Also helping produce horsepower and torque are heads equipped with 24 valves and controlled by dual overhead cams. Running 91-octane fuel is recommended.
The job of transferring power to both axles is handled by Nissan's corporate two-speed transfer case. It is similar to the other transfer cases in this test in that it is made of aluminum and is chain-driven. However, it does feature the highest low-range gearing of our group, at 2.02:1.
Toyota Tacoma 3.4L V-6
Toyota designates the engine powering the Tacoma as the 5VZ-FE. The 3.4L V-6 uses a compression ratio of 9.6:1 and a bore and stroke of 3.68x3.23 to help it create 190 horsepower at 4,800 rpm and 220 lb-ft of torque at 3,600 rpm. More power-producing parts come in the form of 24-valve aluminum heads with dual-overhead cams. A distributorless ignition system sparks fuel that is fed by an electronic fuel-injection system.
Controlling distribution of power is a transfer case built by Aisinseiki, a subsidiary of Toyota. Constructed of aluminum, the part-time transfer case features a low-range of 2.56:1. Shifting the T-case is a lever that uses a button to engage high-range and a rearward pull of the lever itself to find low-range.
Toyota Tundra 4.7L V-8
Our favorite engine of the test was the 4.7L i-Force V-8 that produces 245 horsepower at 4,800 rpm and 315 lb-ft of torque at 4,800 rpm. Lots of technology can be found on this mill. It is the only V-8 of our test to feature four valves per cylinder and double overhead cams. Its block is constructed of cast iron and features a 3.70x3.31 bore-and-stroke and a compression ratio of 9.6:1. Aluminum heads top off this high-tech engine.
Another Aisinseiki transfer case is found under the Tundra. Like the Tacoma's, it is constructed of aluminum, is part-time, and features a 2.56:1 low-range. However, unlike the Tacoma, the Tundra uses a fully electronic system that utilizes buttons to shift the transfer case.