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The absolute best site for chatting about trucks. |
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| History of GM/Chevy engines |
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| Before 1987 all trucks came with carbureted motors. Introduced in 1987, TBI motors were introduced. TBI- throttle body injection, was a form of fuel injection. At a first glance it appears to be a carb, but it is in fact a computerized injection system with a set of injectors located inside the throttle body. |
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| The year 1996, would be a breakthrough year for GM. Technology and innovation led the way for better performance under the name VORTEC. Vortec was a term used to describe the swirling effect (vortex) from the new head design. It didn’t stop there, Roller cam, increased compression ratio, and sequential fuel injection were some of the aspects introduced in the new engines. The jump from 1995 to 1996 was so great that they gained as much as 55 horsepower from the previous year in the 5.7liter. |
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| In 1999, the Vortec name still applied but the engine was even further developed as it was modeled over one of the greatest engines ever produced, the LS1. Based off of the famous motor, it led way to amazing efficiency and performance. Iron blocks, a light weight components, aluminum heads, increased top end power, and a better power band were some of the many new attributes used in this completely overhauled motor. Also the 5.7liter motor was dropped in 1999 to the 4.8/5.3/6.0liter. Although cubic inches were lost from the 350 to the 325, the difference was more than made up for in its increased horsepower and efficiency. |
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| Overview |
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In the 1988-1998 trucks, the TBI motor was used from 1988-1995.
Characteristics: Tons of power and torque off the line, but the power flattens out in the higher RPMs. Not a very easily modified high performance motor due to its design and TBI system. Gas mileage is not great on these motors.
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1996-1998, the vortec 350 was used. Made 255hp and 330ft/lbs of torque.
Characteristics: Better fuel efficiency and more power throughout the rpm range. Responds well to bolt-ons.
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1999-to present, the vortec/ls1 type motors were introduced. The 5.3l motor makes 285hp and 325ft/lbs of torque.
Characteristics: Tremendous power in the top end range, which makes it great for drag racing. Like the earlier vortec motor it responds great to bolt-ons and has great power band.
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| Click for specs on the Vortec motors |
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