There are various types of engine bolts used in automotive engines, including:

1. Cylinder head bolts: these are used to secure the cylinder head to the engine block.

2. Main bearing bolts: these are used to secure the engine's main bearings.

3. Rod bolts: these are used to secure the connecting rods to the crankshaft.

4. Flywheel bolts: these are used to secure the flywheel to the crankshaft.

5. Timing cover bolts: these are used to secure the timing cover to the engine block.

6. Oil pan bolts: these are used to secure the oil pan to the engine block.

7. Camshaft bolts: these are used to secure the camshaft to the cylinder head.

8. Intake and exhaust manifold bolts: these are used to secure the intake and exhaust manifolds to the cylinder head.

9. Water pump bolts: these are used to secure the water pump to the engine block.

These bolts come in various sizes, grades, and materials depending on the application and the manufacturer's specifications. It is important to use the correct bolt for each application to ensure proper fit and function.