Major Components:
* Engine Mounts: You absolutely *need* custom engine mounts. The SR20DE is significantly larger than the GA16DE (or whatever engine your Sentra originally had). You won't find bolt-on solutions; you'll likely need to fabricate these or purchase custom-made ones from a specialist.
* Exhaust System: The SR20DE's exhaust manifold will not line up with your existing exhaust. You'll need a new exhaust manifold, downpipe, and likely a custom cat-back system.
* Driveshaft: The driveshaft from your original engine will almost certainly be too short or have the wrong splines. You'll likely need a custom driveshaft or one from a compatible Nissan model.
* Axles: Similar to the driveshaft, the axles might not be compatible and could require replacement.
* Cooling System: The SR20DE radiator is different. You'll need the SR20DE radiator, hoses, thermostat, and possibly a different fan setup.
* Wiring Harness Modifications (Beyond ECU): While you'll get a harness with the engine, it needs extensive modification to integrate it into your Sentra's existing wiring loom. This involves splicing, adding relays, and potentially rewiring several circuits. This is often the most challenging aspect for many people.
* Fuel System: The fuel injectors and fuel pump might not be compatible. You may need to use the SR20DE's fuel system components or make significant modifications to your existing system.
* Power Steering: The power steering pump and lines may not be compatible.
* Air Intake: You'll need an appropriate air intake system for the SR20DE.
* Clutch and Pressure Plate: These need to be compatible with the SR20DE flywheel and your chosen transmission.
Where to Find Parts:
* Junkyards: This is a great place to find used parts, especially if you are on a budget. Look for SR20DE-equipped Nissan models (like 200SX/S13, Sentra SE-R Spec V, etc.).
* Online Retailers: Companies like eBay, Amazon, and specialized performance parts websites (like Summit Racing, JEGS, etc.) sell many of these components, both new and used.
* Specialty Shops: Performance shops specializing in Nissan engines often carry parts specifically for SR20DE swaps.
* Forums and Communities: Online forums dedicated to Nissan enthusiasts (like SR20 forums) are invaluable resources for finding parts, advice, and connecting with people who have done similar swaps.
Small Things (but still important):
* Bolts and Fasteners: You'll need a variety of bolts, nuts, and washers to complete the swap.
* Fluids: Engine oil, coolant, transmission fluid, brake fluid, power steering fluid.
* Sensors and Switches: Ensure you have all the necessary sensors (e.g., crankshaft position sensor, coolant temperature sensor, etc.) and switches.
* Shifter Linkage: You might need to modify or replace the shifter linkage to match the SR20DE transmission.
* Grounding: Proper grounding is crucial for a reliable swap.
Important Considerations:
* Experience and Skill: This is a significant project requiring mechanical skills and experience. If you are not comfortable with automotive repair, consider having a professional mechanic assist you.
* Safety: Always prioritize safety. Work in a well-ventilated area and follow proper safety procedures.
* Legality: Check your local laws and regulations regarding engine swaps. Some areas have strict rules about modified vehicles.
In short, while the transmission, ECU, and harness are large components, they are only a small fraction of what's involved in a complete SR20DE swap into a 1990 Sentra. It's a complex project that demands meticulous planning, sourcing of parts, and substantial mechanical skill. Thorough research and a well-defined plan are absolutely critical to success.
