* Engine Compatibility: While some Celica engines share components with the MR2, they aren't directly interchangeable. The 1991 MR2 came with a 2.2L 4AGE engine, which has different mounting points, wiring harnesses, and ancillary systems compared to other Celica engines.
* Engine Size and Weight: The MR2's chassis and suspension are designed specifically for the smaller, lighter 4AGE engine. Swapping in a larger or heavier engine could affect handling, balance, and potentially cause stress on the drivetrain.
* Modifications: To successfully swap a different engine, you'll need extensive modifications, including:
* Engine Mounts: Custom mounts will be needed to fit the new engine.
* Wiring Harness: The wiring harness from the Celica engine may need extensive re-wiring to integrate with the MR2's electrical system.
* Exhaust System: The exhaust system will likely need to be modified or replaced entirely.
* Cooling System: The radiator, hoses, and cooling fans might need to be adjusted for the different engine.
* Transmission: Depending on the Celica engine you choose, you may need a compatible transmission and clutch.
Possible Engine Swaps (with extensive modifications):
* 4AGE 20V (from later-model MR2s): This is the most common swap, offering improved performance and is relatively straightforward.
* 3S-GE (from later-model Celicas): This engine is larger and more powerful, but requires more extensive modifications.
* Other Turbocharged Engines: You could consider turbocharged engines like the 3SGTE or 1JZ-GTE, but these are much more complex swaps and often require custom fabrication and extensive engineering.
Considerations before a Swap:
* Cost: Engine swaps are expensive, requiring parts, labor, and potentially specialized fabrication.
* Time Commitment: You'll need significant time and expertise to complete a successful swap.
* Regulations: Some swaps may not meet emissions standards, so check local laws before proceeding.
* Warranty: Swapping engines will void any existing warranties.
Recommendation:
If you're looking to improve performance, consider upgrading the existing 4AGE engine with performance parts, or researching a reliable, proven swap like the 4AGE 20V.
Remember: Always consult with a professional mechanic or experienced engine swapper before attempting any major engine modifications.
