The Ultimate E30 S50 Swap Guide: from Engine Removal to Dyno Testing

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The E30 BMW is a beloved classic among car enthusiasts, and one of the most popular modifications is the S50 engine swap. This guide will take you through the entire process, from engine removal to dyno testing, ensuring that you have all the information you need to successfully complete your S50 swap.

Understanding the E30 and S50 Engine

The E30, produced from 1982 to 1994, is known for its lightweight chassis and excellent handling. The S50 engine, originally from the E36 M3, offers a significant power upgrade and a thrilling driving experience. Before starting the swap, it’s essential to understand the compatibility and requirements of both the E30 and S50 engines.

  • Lightweight chassis of the E30
  • Powerful S50 engine from E36 M3
  • Benefits of the swap: increased horsepower and torque

Preparation for the Swap

Before diving into the swap, proper preparation is crucial. Gather all necessary tools and parts to streamline the process. Here’s a checklist to help you get started:

  • Tools: socket set, wrenches, screwdrivers, engine hoist
  • Parts: S50 engine, E30 engine mounts, transmission, wiring harness
  • Safety gear: gloves, goggles, and a sturdy work surface

Engine Removal

Removing the stock engine from your E30 is the first step in the swap process. Follow these steps for a smooth removal:

  • Disconnect the battery to ensure safety.
  • Drain the engine fluids: oil and coolant.
  • Remove the intake and exhaust systems.
  • Disconnect all wiring harnesses and sensors.
  • Unbolt the engine from the transmission and mounts.
  • Use an engine hoist to lift the engine out of the bay.

Preparing the S50 Engine

With the E30 engine removed, it’s time to prepare the S50 for installation. Here’s what you need to do:

  • Inspect the S50 for any damage or wear.
  • Replace any worn gaskets and seals.
  • Install the E30 engine mounts on the S50.
  • Transfer any necessary components from the E30 engine to the S50.

Installing the S50 Engine

Now that the S50 is prepared, it’s time to install it into the E30. Follow these steps for a successful installation:

  • Position the engine hoist over the engine bay.
  • Carefully lower the S50 into place.
  • Align the engine with the transmission and mounts.
  • Secure the engine with bolts and ensure all connections are tight.

Wiring and Electronics

Wiring is a critical part of the S50 swap. You will need to connect the S50 wiring harness to the E30’s electrical system. Here’s how:

  • Refer to wiring diagrams for both the E30 and S50.
  • Connect the necessary sensors and ECU.
  • Ensure that all grounds are properly connected.
  • Test electrical connections before starting the engine.

Cooling System Setup

The cooling system is vital for the performance and longevity of your S50 engine. Follow these steps to set it up correctly:

  • Install the S50 radiator or use an E30 radiator with modifications.
  • Connect the coolant hoses to the engine and radiator.
  • Fill the system with coolant and check for leaks.

Exhaust System Installation

Installing the exhaust system is the next step. You have options depending on your desired sound and performance:

  • Use an aftermarket S50 exhaust manifold for better flow.
  • Connect to the existing E30 exhaust or upgrade to a performance exhaust.
  • Ensure all connections are secure to prevent leaks.

Final Checks Before Starting

Before starting your newly swapped S50 engine, perform these final checks:

  • Double-check all fluid levels: oil, coolant, and fuel.
  • Inspect all connections: wiring, hoses, and mounts.
  • Ensure the battery is fully charged.

Starting the Engine

Now it’s time for the moment of truth. Follow these steps to start your S50 engine for the first time:

  • Turn the key to the ON position and check for warning lights.
  • Crank the engine and listen for unusual noises.
  • Allow the engine to idle and check for leaks.

Dyno Testing

After a successful start, it’s recommended to take your E30 to a dyno for testing. This will help you understand the performance gains from the swap:

  • Schedule a dyno appointment with a reputable shop.
  • Monitor power output and torque measurements.
  • Make adjustments as necessary based on dyno results.

Conclusion

Completing an S50 swap in your E30 can be a rewarding project that enhances performance and driving enjoyment. With the right preparation and attention to detail, you can successfully complete the swap and enjoy the benefits of your upgraded engine.