Conversion - LT1 Gen II Small Block Chevy
The LT1 was introduced in the ’92 Corvette and subsequently used in the
’93-‘97 Camaro and Firebird. It was designed to have a very low profile
under the hood compared to the earlier Tuned Port Chevy small block. It
features aluminum heads and EFI manifold, a roller cam, one-piece rear
main seal, and a cast-iron block. Unusual features are the
camshaft-driven water pump with no mechanical fan pulley; reverse flow
cooling, and Opti-Spark electronic distributor mounted behind the water
pump. Reverse flow cooling means water from the radiator flows to the
cylinder head passages first, then to the block. This allows the LT1 to
use a relatively high compression ratio of 10.5:1 on pump gas without
experiencing detonation problems. Two excellent articles describing the
engine in more detail are attached to the end of this document: one
describing the cooling system and another dealing with rebuilding the LT1.
The pros of using this engine in an H-body conversion are:
- Excellent performance in stock configuration: 285-330 HP
- Excellent mileage- over 20 MPG highway
- Smooth running and dependable due to EFI
- Cool running engine due to reverse-flow cooling
- Low deck height for under-hood clearance
- Over 100 pounds lighter than all cast-iron engine—525 pounds with accessories
- Camaro/Firebird oil pan is notched like aftermarket H-body pan
- Same dimensions as SBC with short water pump from bell housing flange to front of LT1 water pump—27 ˝ "
- Mounts like standard SBC engine
- Can use any transmission combination
- Flat torque curve throughout the RPM range
Cons of the LT1 conversion are:
- Need to use electric fan(s) due to lack of mechanical fan
- Limited clearance in front of water pump for both radiator and fan(s)
- Need to use either pusher fan (less efficient) or radiator in front of core support with remote fill
- Wiring integration
- Must use aftermarket (expensive!) or fabricated serpentine accessory drive belt system
- May have to use spacers to raise engine for pan clearance when using V-8 Monza mounts
- You can get equal or better HP/Torque out of a Gen I SBC with a carburetor
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