" GRUMPY? Im looking at the later 1992-1996 LT1 and LT4 corvettes are some years better or worse?"
The LT4 is a one year only (1996) engine and only came in manual transmission cars, (GRAND SPORTS) its got a few part upgrades making it noticeably better for performance.
Id also point out that the 1996 LT1 had several improvements, especially the OPTI SPARK IGNITION was improved, the 1996 is a much better LT1 than the 1992-1994 version, enough better that ID pay a bit more and concentrate on finding a clean 1996.
because the LT series engines were only offered during a fairly short run, theres not a great deal of aftermarket parts offered but there is a some parts interchangeability with the standard SBC
http://www.grandsportregistry.com/lt1vslt4.htm
http://www.grandsportregistry.com/lt1vslt4_intakes.htm
viewtopic.php?f=36&t=628&p=15040&hilit=opti#p15040
viewtopic.php?f=44&t=758&p=1087&hilit=opti#p1087
viewtopic.php?f=50&t=118&p=148&hilit=opti#p148
viewtopic.php?f=44&t=4608&p=12299&hilit=opti#p12299
What are the LT1 basic specs?
Block and Basics
Displacement: 350 cubic inches, 5733 cubic centimeters, 5.7 liters
Block Material: Cast Iron
Main Bearings: 2-Bolt Centers and Ends (The Corvette LT1/LT4 had 4-bolt mains)
Stroke: 3.48"
Bore: 4.00"
Compression Ratio: 10.4:1
Combustion Chambers: 54 cubic centimeters
Factory Redline Rating: 5700 Rotations Per Minute
Bottom End
Piston Material: (10159437) Eutectic Aluminum/Silicon Alloy
Connecting Rod Material: (10108688) Powdered Metal
Crankshaft Material: (12556307) Cast Iron
Top End and Valvetrain
Cylinder Heads: (10168448) Cast Aluminum, 2 valves per cylinder/16 valves total, ~212 CFM flow (Impala SS and Caprice heads were made of cast iron*) Valve Diameter: (intake- 10241743, exhaust- 12550909) 1.94 intake, 1.50 exhaust
Valve Overlap: 41*
Valvesprings: (10206040) 85 lbs, seated
Camshaft Specs (12551705): 205/207 duration @ 50*, .447/.459" lift, 117 Lobe Seperation Angle
Rocker Arms: (10089648) 1.5:1 Stamped Steel
Timing Chain: (10128485) Powdered metal butt link
Intake and Fuel Delivery
Fuel Delivery: Electronic Fuel Injection, sequential port
Injector Size: (17124248) 3.0gps, 22lbs/hr speed density (1992-1993), 24lbs/hr mass airflow (1994-1997)
Throttle Body: 48 millimeter twin butterfly
Intake Manifold: (12552137) Aluminum
Factory Power Ratings
92-96 LT1 Corvette: 300bhp, 330lb-ft
1996 LT4 Corvette: 330bhp, 340lb-ft
1992 LT5 Corvette: 375bhp, 370lb-ft
93-95 LT5 Corvette: 405bhp, 385lb-ft
93-95 LT1 F-Body: 275bhp, 325lb-ft
96-97 LT1 F-Body: 285bhp, 325lb-ft
96-97 WS6/SS: 305bhp, 335lb-ft
93-97 Firehawks: 315bhp, 340lb-ft
Factory LTX Camshaft Specifications**:
1992 Y-body: 205/207 0.451/0.450 lift 117 LSA
1993-1995 Y-body, F-body: 202/207 0.450/0.460 lift 116 LSA
1994-1996 B-bodies (including L99 4.3L): 191/196 0.418/0.430 lift 111 LSA
1996 Y-body, 1996-1997 F-body: 200/207 0.447/0.459 lift 117 LSA
1996 Y-body, F-body LT4: 203/210 0.476/0.479 lift 115 LSA
* Cast iron heads are known to flow better, but are also more prone to heat-soak than aluminum heads.
The LT4 is a one year only (1996) engine and only came in manual transmission cars, (GRAND SPORTS) its got a few part upgrades making it noticeably better for performance.
Id also point out that the 1996 LT1 had several improvements, especially the OPTI SPARK IGNITION was improved, the 1996 is a much better LT1 than the 1992-1994 version, enough better that ID pay a bit more and concentrate on finding a clean 1996.
because the LT series engines were only offered during a fairly short run, theres not a great deal of aftermarket parts offered but there is a some parts interchangeability with the standard SBC
http://www.grandsportregistry.com/lt1vslt4.htm
http://www.grandsportregistry.com/lt1vslt4_intakes.htm
viewtopic.php?f=36&t=628&p=15040&hilit=opti#p15040
viewtopic.php?f=44&t=758&p=1087&hilit=opti#p1087
viewtopic.php?f=50&t=118&p=148&hilit=opti#p148
viewtopic.php?f=44&t=4608&p=12299&hilit=opti#p12299
What are the LT1 basic specs?
Block and Basics
Displacement: 350 cubic inches, 5733 cubic centimeters, 5.7 liters
Block Material: Cast Iron
Main Bearings: 2-Bolt Centers and Ends (The Corvette LT1/LT4 had 4-bolt mains)
Stroke: 3.48"
Bore: 4.00"
Compression Ratio: 10.4:1
Combustion Chambers: 54 cubic centimeters
Factory Redline Rating: 5700 Rotations Per Minute
Bottom End
Piston Material: (10159437) Eutectic Aluminum/Silicon Alloy
Connecting Rod Material: (10108688) Powdered Metal
Crankshaft Material: (12556307) Cast Iron
Top End and Valvetrain
Cylinder Heads: (10168448) Cast Aluminum, 2 valves per cylinder/16 valves total, ~212 CFM flow (Impala SS and Caprice heads were made of cast iron*) Valve Diameter: (intake- 10241743, exhaust- 12550909) 1.94 intake, 1.50 exhaust
Valve Overlap: 41*
Valvesprings: (10206040) 85 lbs, seated
Camshaft Specs (12551705): 205/207 duration @ 50*, .447/.459" lift, 117 Lobe Seperation Angle
Rocker Arms: (10089648) 1.5:1 Stamped Steel
Timing Chain: (10128485) Powdered metal butt link
Intake and Fuel Delivery
Fuel Delivery: Electronic Fuel Injection, sequential port
Injector Size: (17124248) 3.0gps, 22lbs/hr speed density (1992-1993), 24lbs/hr mass airflow (1994-1997)
Throttle Body: 48 millimeter twin butterfly
Intake Manifold: (12552137) Aluminum
Factory Power Ratings
92-96 LT1 Corvette: 300bhp, 330lb-ft
1996 LT4 Corvette: 330bhp, 340lb-ft
1992 LT5 Corvette: 375bhp, 370lb-ft
93-95 LT5 Corvette: 405bhp, 385lb-ft
93-95 LT1 F-Body: 275bhp, 325lb-ft
96-97 LT1 F-Body: 285bhp, 325lb-ft
96-97 WS6/SS: 305bhp, 335lb-ft
93-97 Firehawks: 315bhp, 340lb-ft
Factory LTX Camshaft Specifications**:
1992 Y-body: 205/207 0.451/0.450 lift 117 LSA
1993-1995 Y-body, F-body: 202/207 0.450/0.460 lift 116 LSA
1994-1996 B-bodies (including L99 4.3L): 191/196 0.418/0.430 lift 111 LSA
1996 Y-body, 1996-1997 F-body: 200/207 0.447/0.459 lift 117 LSA
1996 Y-body, F-body LT4: 203/210 0.476/0.479 lift 115 LSA
* Cast iron heads are known to flow better, but are also more prone to heat-soak than aluminum heads.
