Exhaust System

MANIFOLDS AND EXHAUST SYSTEM – V8

30-2-6

DESCRIPTION AND OPERATION

Description

General
The inlet manifold on the V8 engine is located on the top of the engine, between the cylinders.

The two exhaust manifolds, one for each bank of four cylinders, directs the engine combustion gases from the 
cylinders to the exhaust system. 

The exhaust system consists of two identical systems, sharing a common rear silencer assembly, connected to each 
exhaust manifold. Two catalytic converters are located in each of the front pipes from it's respective manifold and a 
silencer is installed midway along the system. 

Inlet Manifold
The inlet manifold is a light weight, one piece plastic moulding. The manifold is acoustically decoupled from the 
cylinder heads to reduce noise and vibrations.

The throttle plate has two wedges screwed directly to it, these provide a curved zone for smoother throttle response 
during idle, off-idle transition.

The combined output of the mixing plate ensures that the intake air is evenly distributed among all the cylinders, which 
can improve idle quality.

Exhaust Manifold
Two handed, double skinned stainless steel sheet metal manifolds are used on the V8 engine. Each manifold has four 
ports which merge into one flanged outlet positioned centrally on the manifold. 

Each manifold is secured to its cylinder head using eight studs with nuts and sealed with two gaskets. The flanged 
outlet on each manifold provides the attachment for the exhaust system.

NOTE: The exhaust manifold gasket for cylinders 3–4 is not interchangeable with the gaskets for cylinders 1–2, 5–6 
or 7–8. 

Exhaust System
The stainless steel exhaust system is supplied as a one-piece assembly. 

It consists of two stub pipes and pre-catalytic converter HO2S, two intermediate catalytic converters, two main 
catalytic converters and down pipes, each with a post catalytic converter HO2S, two intermediate silencer assemblies 
and pipes joining the single rear silencer assembly. Internally the rear silencer assembly is divided into two 
independent silencers, each with its own tailpipe. The tail pipes are bent downwards and not normally visible.
 

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 ENGINE MANAGEMENT SYSTEM – V8, DESCRIPTION AND OPERATION, Bosch ME 7.2 Engine 

Management System.

The exhaust system is attached to the underside of the body with five rubber mountings and a mass damper. The 
mass damper is fitted forward of the right intermediate silencer.

Although supplied as a one-piece assembly, in service, sections of the system can be replaced individually. Service 
joints, identified by indentations on the pipes, show where the exhaust pipes can be cut to accommodate replacement 
sections.

After the replacement sections are positioned the system integrity is restored by sealing the service joints with one 
piece sleeves. For more information, refer to the Service Procedures Workshop manual.