What years came w/ vortec engine?
RE: What years came w/ vortec engine?
I'm going to do this from memory so all the information might not be correct. I'll try to track down a link with the history if I can.
The Vortec named engine came out in '92 IIRC. It has gone through several iterations, most of which has dealt with different fuel injection systems. The 92-95 came with the CPI (central port injection?) which was a batch fire injection system that only fired a main injector feeding 6 poppet injectors all at the same time. The injector pulse width was determined by one main O2 sensor. In '96 they switched over to the CSPI (Central sequencial fuel injection) which made the full transition to fully independent banks with IPW changes determined by an O2 sensor for each bank.
The basic vortec (vortex) design came out much earlier ('88 I think for the tbi 4.3L v6) and was created to make full use of the turbulence of the air as it enters into the combustion chamber. The design of the intake runners, valve bowls, and the combustion chamber itself all aid in creating a more uniform air fuel mixture by spinning said mixture as it entered the combustion chamber.
The Vortec name is just that. GM tried to tout it as something big, but, like the Magnum line of later model Mopars, it really is just a major design change to older proven technology.
*EDIT* - Ok found the data
The Vortec named engine came out in '92 IIRC. It has gone through several iterations, most of which has dealt with different fuel injection systems. The 92-95 came with the CPI (central port injection?) which was a batch fire injection system that only fired a main injector feeding 6 poppet injectors all at the same time. The injector pulse width was determined by one main O2 sensor. In '96 they switched over to the CSPI (Central sequencial fuel injection) which made the full transition to fully independent banks with IPW changes determined by an O2 sensor for each bank.
The basic vortec (vortex) design came out much earlier ('88 I think for the tbi 4.3L v6) and was created to make full use of the turbulence of the air as it enters into the combustion chamber. The design of the intake runners, valve bowls, and the combustion chamber itself all aid in creating a more uniform air fuel mixture by spinning said mixture as it entered the combustion chamber.
The Vortec name is just that. GM tried to tout it as something big, but, like the Magnum line of later model Mopars, it really is just a major design change to older proven technology.
*EDIT* - Ok found the data
How to identify your 4.3L
These 4.3's are 90 degree even-fire engines, with a 1-6-5-4-3-2 firing order. All have overhead valves, with two valves per cylinder. Cylinders are: 1-3-5 (Driver's side front to back) 2-4-6 (Passenger side front to back)
The VIN engine digit is the 8th in the code. RPO list is in your glovebox.
VIN Z, RPO LB4:
Throttle Body Injection (TBI). Manufactured from 1988-1995. Was the first 4.3 used in the S-series. Manifold setup is similar to a carberated engine. The TBI unit looks like an electronically regulated carberator and the air filter sits directly on top of it. It has two injectors in a pod above the throttle plates. Injectors are batch-fired.
155 to 165 hp, 235ft/lbs
NOTE:The 4.3L in the Syclones/Typhoons is also VIN Z, LB4. The block and cylinder heads are the same as the LB4 TBI, with the exception of lower-compression pistons and nodular iron main caps. Boost is provided by a Mistubishi TD06-17C at 550 CFM. Fuel injectors and throttle body are borrowed from L98 Corvette/F-body V8's. The fuel injectors are fed through fuel rails and are batch-fired.
280hp, 350ft/lbs in 1991-1992.
290hp, 360ft/lbs in 1993 Typhoons.
VIN W, RPO L35:
Central Port Injection (CPI/CMPI). Manufactured from 1992-1995. It has central injection assembly mounted in the intake manifold which uses a single batch-fired injector feeding 6 poppet nozzels located at the intake ports. It has a dual-plenum manifold (upper and lower) with variable tuning with a manifold tuning valve to equalize pressure. The manifold looks much like that of an LT1, the throttle body is at the front of the manifold and goes to an intake tube with a filter box behind the left headlight. Vortec is written in orange on top of the plenum, which is black or aluminum colored.
190 to 195hp, 260ft/lbs
VIN X, RPO LF6:
Central Sequential Fuel Injection (CSFI), Sequential Fuel Injection (SFI).Manufactured from 1996 to 1999. CSFI uses six individual injectors and a fuel pressure regulator that pulses fuel through six orifices through flexible nylon tubes. These tubes run to poppet valves at the intake ports. Manifold setup is similar to TBI, except it has one bore and one throttle blade. Air filter box is located behind driver?s side headlight.
175hp, 240ft/lbs (2wd pickups), 180hp, 245ft/lbs (4x4 pickups)
VIN W, RPO L35:
Central Sequential Fuel Injection (CSFI), Sequential Fuel Injection (SFI). Manufactured from 1996 to 2003. This engine is similar to the VIN X, RPO LF6 except for increased hp and torque. The only likely difference is computer programming.
180hp, 245ft/lbs (2wd pickups), 190hp, 250ft/lbs (Blazers and 4x4s)
These 4.3's are 90 degree even-fire engines, with a 1-6-5-4-3-2 firing order. All have overhead valves, with two valves per cylinder. Cylinders are: 1-3-5 (Driver's side front to back) 2-4-6 (Passenger side front to back)
The VIN engine digit is the 8th in the code. RPO list is in your glovebox.
VIN Z, RPO LB4:
Throttle Body Injection (TBI). Manufactured from 1988-1995. Was the first 4.3 used in the S-series. Manifold setup is similar to a carberated engine. The TBI unit looks like an electronically regulated carberator and the air filter sits directly on top of it. It has two injectors in a pod above the throttle plates. Injectors are batch-fired.
155 to 165 hp, 235ft/lbs
NOTE:The 4.3L in the Syclones/Typhoons is also VIN Z, LB4. The block and cylinder heads are the same as the LB4 TBI, with the exception of lower-compression pistons and nodular iron main caps. Boost is provided by a Mistubishi TD06-17C at 550 CFM. Fuel injectors and throttle body are borrowed from L98 Corvette/F-body V8's. The fuel injectors are fed through fuel rails and are batch-fired.
280hp, 350ft/lbs in 1991-1992.
290hp, 360ft/lbs in 1993 Typhoons.
VIN W, RPO L35:
Central Port Injection (CPI/CMPI). Manufactured from 1992-1995. It has central injection assembly mounted in the intake manifold which uses a single batch-fired injector feeding 6 poppet nozzels located at the intake ports. It has a dual-plenum manifold (upper and lower) with variable tuning with a manifold tuning valve to equalize pressure. The manifold looks much like that of an LT1, the throttle body is at the front of the manifold and goes to an intake tube with a filter box behind the left headlight. Vortec is written in orange on top of the plenum, which is black or aluminum colored.
190 to 195hp, 260ft/lbs
VIN X, RPO LF6:
Central Sequential Fuel Injection (CSFI), Sequential Fuel Injection (SFI).Manufactured from 1996 to 1999. CSFI uses six individual injectors and a fuel pressure regulator that pulses fuel through six orifices through flexible nylon tubes. These tubes run to poppet valves at the intake ports. Manifold setup is similar to TBI, except it has one bore and one throttle blade. Air filter box is located behind driver?s side headlight.
175hp, 240ft/lbs (2wd pickups), 180hp, 245ft/lbs (4x4 pickups)
VIN W, RPO L35:
Central Sequential Fuel Injection (CSFI), Sequential Fuel Injection (SFI). Manufactured from 1996 to 2003. This engine is similar to the VIN X, RPO LF6 except for increased hp and torque. The only likely difference is computer programming.
180hp, 245ft/lbs (2wd pickups), 190hp, 250ft/lbs (Blazers and 4x4s)
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