Engine Components

CYLINDER HEAD COVER
A steel-backed silicone gasket is used with the cylinder head cover. This gasket is reusable.

EXHAUST MANIFOLD
The exhaust manifolds are constructed of cast iron and are LOG type with balanced flow.

INTAKE MANIFOLD
The aluminum intake manifold is a single plane design with equal length runners. The manifold is sealed by flange side gaskets with front and rear cross-over gaskets.

CYLINDER HEADS

Cylinder Head Assembly:

The alloy cast iron cylinder heads are held in place by eight bolts. The spark plugs are located in at peak of the wedge between the valves.
VALVES AND VALVE SPRINGS
The valves are arranged in-line and inclined 18°. The rocker pivot support and the valve guides are cast integral with the heads.

TIMING CHAIN TENSIONER
A stamped steel mechanical chain tensioner is mounted to the front of the engine, behind the timing drive, and maintains chain tension by way of a pivoting nylon covered spring steel arm. A fixed, nylon covered pad is used on the opposite side of the tensioner. This tensioner design reduces noise generated by typical chain driven systems.

OIL PUMP
OIL PUMP PRESSURE
The MINIMUM oil pump pressure is 41.4 kPa (6 psi) at curb idle. The NORMAL oil pump pressure is 207 - 552 kPa (30 - 80 psi) at 3,000 RPM or more.

CAUTION: If oil pressure is ZERO at curb idle, DO NOT run engine.

PISTON AND CONNECTING ROD ASSEMBLY
The pistons are elliptically turned so that the diameter at the pin boss is less than its diameter across the thrust face. This allows for expansion under normal operating conditions. Under operating temperatures, expansion forces the pin bosses away from each other, causing the piston to assume a more nearly round shape.
All pistons are machined to the same weight, regardless of size, to maintain piston balance.
The piston pin rotates in the piston only and is retained by the press interference fit of the piston pin in the connecting rod.

CRANKSHAFT
A crankshaft that has undersized journals is stamped with 1/4 inch letters near the notch of the No. 6 crankshaft counterweight.
FOR EXAMPLE: R2 stamped on the No. 6 crankshaft counterweight indicates that the No.2 rod journal is 0.025 mm (0.001 inch) undersized. M4 indicates that the No. 4 main journal is 0.025 mm (0.001 inch) undersized. R3 M2 indicates that the No. 3 rod journal and the No. 2 main journal are both 0.025 mm (0.001 inch) undersized.
When a crankshaft is replaced, all main and connecting rod bearings, should be replaced with new bearings. Therefore, selective fitting of the bearings is not required when a crankshaft and bearings are replaced.

CRANKSHAFT MAIN BEARINGS
Bearing caps are NOT interchangeable and should be marked at removal to ensure correct assembly. Upper and lower bearing halves are NOT interchangeable. Lower main bearing halves of No.1 and 3 are interchangeable.
Upper and lower No. 2 bearing halves are flanged to carry the crankshaft thrust loads. They are NOT interchangeable with any other bearing halves in the engine. Bearing shells are available in standard and the following undersizes: 0.25 mm (0.001 inch), 0.051 mm (0.002 inch), 0.076 mm (0.003 inch), 0.254 mm (0.010 inch) and 0.305 mm (0.012 inch). Never install an undersized bearing that will reduce clearance below specifications.

CRANKSHAFT REAR OIL SEALS
The service seal is a two piece, Viton seal. The upper seal half can be installed with crankshaft removed from engine or with crankshaft installed. When a new upper seal is installed, install a new lower seal. The lower seal half can be installed only with the rear main bearing cap removed.

INTAKE MANIFOLD
The aluminum intake manifold is a single plane design with equal length runners. The manifold is sealed by flange side gaskets with front and rear cross-over gaskets.

EXHAUST MANIFOLD
Exhaust manifolds are cast iron LOG type with balanced flow.