About the 4AGE 20V Engine
The 4AGE 20V engine is a popular and highly regarded engine produced by Toyota. It is a 1.6-liter, four-cylinder engine that was first introduced in the late 1980s. The 20V designation refers to the number of valves the engine has – 20 valves, with 5 valves per cylinder. This engine is known for its high-revving nature, smooth power delivery, and excellent performance. It has become a favorite among car enthusiasts and is often used in various motorsport applications.
Head Bolt Torque Specifications
When working on the 4AGE 20V engine, it is crucial to ensure that the head bolts are torqued to the correct specifications. This ensures proper sealing of the cylinder head to the engine block and prevents any leaks or damage. The following table provides the recommended head bolt torque specifications for the 4AGE 20V engine:
| Head Bolt | Torque (ft. lbs.) | Torque (Nm) |
|---|---|---|
| 1 | 22 | 30 |
| 2 | 43 | 59 |
| 3 | 43 | 59 |
| 4 | 43 | 59 |
| 5 | 43 | 59 |
| 6 | 43 | 59 |
| 7 | 43 | 59 |
| 8 | 43 | 59 |
Steps to Torque the Head Bolts
To torque the head bolts of the 4AGE 20V engine, follow these steps:
1. Begin by cleaning the threads of the head bolts and the corresponding holes in the engine block. This ensures proper engagement and accurate torque readings.
2. Apply a small amount of engine oil or assembly lubricant to the threads and washer face of each head bolt. This helps reduce friction during the torquing process.
3. Start by torquing all the head bolts to 22 ft. lbs. (30 Nm) in the numerical order specified in the table above. Use a torque wrench and ensure the torque is applied gradually and evenly.
4. Once all the head bolts have been torqued to 22 ft. lbs. (30 Nm), repeat the process and torque them all to 43 ft. lbs. (59 Nm) in the same numerical order.
5. Finally, perform a third pass and torque all the head bolts to 43 ft. lbs. (59 Nm) once again, ensuring even and gradual torque application.
6. Double-check that all the head bolts are tightened to the specified torque values using a torque wrench.
By following these steps and using the correct torque specifications, you can ensure that the head bolts of the 4AGE 20V engine are properly tightened, providing a secure seal and optimal performance.
Remember, it is essential to refer to the specific service manual or manufacturer’s instructions for your engine to ensure accurate and up-to-date torque specifications.