What year did they start the reverse flow cooling with the chevy motors? (im guessing late 80's?? 88-up) Is it just the water pump and rad they changed to do this or is the heads and intake different also? Is there a way to tell just by looking at the motor? Always wondered. Also why did they do this change? does it really cool the motor down faster??? ++peace
as far as i know they didnt reverse flow the smallblocks. in 87 when they went to the serp belts the waterpump spins the opposite direction becuase of
using the back side of the belt to drive it. but the flow is the same direction
lt1 are reverse flow. i believe the system cools the heads before the block.
Quote from: Le Dude on September 26, 2011, 11:16:42 AM
lt1 are reverse flow. i believe the system cools the heads before the block.
And no coolent flows thru the intake.
the reverse cool lt1 came out in 92 or 93 in the corvette and followed the next year with the camaro and firebird, the water pump is driven directly off the camshaft rather than off the older pully system, that's the easiest way to distinguish the 2 motors. no coolent enters teh intake(unless you got some serious problems) umlike the older 350's. the serpentine waterpump for the older blocks only rotates in the opposite direction, that change was made in 87 for most of gm's cars and in 88 for most of the trucks.. some of the early grooved flat belt systems looked like the serpentine system, but the pully still rotated in the clockwise direction like the older v-belt style, the 2 types of pumps for the older blocks are interchangeable as long as the rest of the pully system goes with it.... can't run a serp pump on a v-belt setup and vise versa. but the lt1 style cannot go on the older blocks
Quote from: Le Dude on September 26, 2011, 11:16:42 AM
lt1 are reverse flow. i believe the system cools the heads before the block.
yes, the aluminum headed engines are reverse flow for the most part. i thought he was talking about the regular 350
LT1
GM LT1 from a 1993 Chevrolet Camaro Z28.In 1992, GM created a new-generation small-block engine called the LT1, not to be confused with the high-output Generation I LT-1 of the 1970s. It displaced 5.7 L (350 cu in) and was a 2-valve pushrod design. The LT1 used a reverse-flow cooling system which cooled the cylinder heads first, maintaining lower cylinder temperatures and allowing the engine to run at a higher compression than its immediate predecessors.
This engine was used in:
Y-body:
1992–1996 Chevrolet Corvette C4
F-body:
1993–1997 Chevrolet Camaro Z28, B4C and SS
1993–1997 Pontiac Firebird Formula and Trans Am
B-body:
1994-1996 Buick Roadmaster
1994–1996 Chevrolet Caprice
1994–1996 Chevrolet Caprice Police Package
1994–1996 Chevrolet Impala SS
1994–1996 Chevrolet Caprice Wagon
1994–1996 Buick Roadmaster Wagon
D-body:
1994–1996 Cadillac Fleetwood
There were a few different versions of the LT1. All feature a cast iron block, with aluminum heads in the Y and F bodies, and cast iron heads in the B and D bodies. Corvette blocks had four-bolt main caps, while most other blocks were two-bolt main caps.
The 92–93 LT1s used speed density fuel management, batch-fire fuel injection and a dedicated engine control module (ECM). In 94 the LT1 switched to a mass airflow sensor and sequential port injection. A new, more capable computer controlled the transmission as well as the engine and got a new name: powertrain control module (PCM). Where the ECM held its calibration information in a replaceable chip, the PCM was reprogrammable through the diagnostic port.
The early Optispark distributor had durability problems and a revised version was introduced with vacuum vents to remove moisture on the 1994 B-Bodies and in 1995 on the Y and F-Bodies; the vacuum vents can be added onto earlier distributors.[1] 1996 saw major revisions for OBD-II: a second catalytic converter on the F-body cars and rear oxygen sensors to monitor catalyst efficiency. Some OBD-II features had been added to the Corvette starting in 1994 for testing purposes.[citation needed] The 1997 model year Camaro and Firebird were the last year for this engine in a GM production car before it was replaced by the LS1, which was already in the Corvette for 1997.
The 1992 LT1 in the Y-body was factory rated at 300 hp (220 kW) and 330 lb·ft (447 N·m). 96 LT1 Y-bodies were rated at 300 hp (220 kW) and 340 lb·ft (461 N·m). The 93–95 F-bodies were rated at 275 horsepower (205 kW) and 325 lb·ft (441 N·m), while the 96–97 cars were rated at 285 horsepower (213 kW) and 335 lb·ft (454 N·m). The 96–97 WS6 and SS F-bodies were rated at 305 hp (227 kW). The 94–96 B and D-body version was rated at 260 horsepower (190 kW) and 330 lb·ft (447 N·m).
Quote from: TopFist on September 27, 2011, 12:49:53 AM
LT1
GM LT1 from a 1993 Chevrolet Camaro Z28.In 1992, GM created a new-generation small-block engine called the LT1, not to be confused with the high-output Generation I LT-1 of the 1970s. It displaced 5.7 L (350 cu in) and was a 2-valve pushrod design. The LT1 used a reverse-flow cooling system which cooled the cylinder heads first, maintaining lower cylinder temperatures and allowing the engine to run at a higher compression than its immediate predecessors.
This engine was used in:
Y-body:
1992–1996 Chevrolet Corvette C4
F-body:
1993–1997 Chevrolet Camaro Z28, B4C and SS
1993–1997 Pontiac Firebird Formula and Trans Am
B-body:
1994-1996 Buick Roadmaster
1994–1996 Chevrolet Caprice
1994–1996 Chevrolet Caprice Police Package
1994–1996 Chevrolet Impala SS
1994–1996 Chevrolet Caprice Wagon
1994–1996 Buick Roadmaster Wagon
D-body:
1994–1996 Cadillac Fleetwood
There were a few different versions of the LT1. All feature a cast iron block, with aluminum heads in the Y and F bodies, and cast iron heads in the B and D bodies. Corvette blocks had four-bolt main caps, while most other blocks were two-bolt main caps.
The 92–93 LT1s used speed density fuel management, batch-fire fuel injection and a dedicated engine control module (ECM). In 94 the LT1 switched to a mass airflow sensor and sequential port injection. A new, more capable computer controlled the transmission as well as the engine and got a new name: powertrain control module (PCM). Where the ECM held its calibration information in a replaceable chip, the PCM was reprogrammable through the diagnostic port.
The early Optispark distributor had durability problems and a revised version was introduced with vacuum vents to remove moisture on the 1994 B-Bodies and in 1995 on the Y and F-Bodies; the vacuum vents can be added onto earlier distributors.[1] 1996 saw major revisions for OBD-II: a second catalytic converter on the F-body cars and rear oxygen sensors to monitor catalyst efficiency. Some OBD-II features had been added to the Corvette starting in 1994 for testing purposes.[citation needed] The 1997 model year Camaro and Firebird were the last year for this engine in a GM production car before it was replaced by the LS1, which was already in the Corvette for 1997.
The 1992 LT1 in the Y-body was factory rated at 300 hp (220 kW) and 330 lb·ft (447 N·m). 96 LT1 Y-bodies were rated at 300 hp (220 kW) and 340 lb·ft (461 N·m). The 93–95 F-bodies were rated at 275 horsepower (205 kW) and 325 lb·ft (441 N·m), while the 96–97 cars were rated at 285 horsepower (213 kW) and 335 lb·ft (454 N·m). The 96–97 WS6 and SS F-bodies were rated at 305 hp (227 kW). The 94–96 B and D-body version was rated at 260 horsepower (190 kW) and 330 lb·ft (447 N·m).
Thats what I was looking for. Thanks everyone for the input. Cleared a lot of questions up I had.