Exhaust Exhaust Manifolds & Headers

Question 1

What is the primary purpose of an exhaust manifold?

Accepted Answer

To collect exhaust gases from cylinders and route them to the exhaust pipe

Answer

To cool exhaust gases

Answer

To reduce exhaust noise

Answer

To regulate exhaust pressure

Question 2

What material is most commonly used to manufacture OEM exhaust manifolds on passenger vehicles?

Accepted Answer

Cast iron

Answer

Aluminum

Answer

Stainless steel

Answer

Titanium

Question 3

What is the main advantage of aftermarket exhaust headers over stock exhaust manifolds?

Accepted Answer

They reduce exhaust back pressure and increase engine performance

Answer

They are cheaper to produce

Answer

They are quieter

Answer

They are compatible with more vehicles

Question 4

What is an 'equal-length header' designed to achieve?

Accepted Answer

Identical exhaust pulse timing from each cylinder for better scavenging

Answer

Equal weight distribution in the engine bay

Answer

Uniform heat distribution across the exhaust

Answer

Equal cost per cylinder

Question 5

What typically causes an exhaust manifold to crack?

Accepted Answer

Repeated thermal cycling causing metal fatigue

Answer

Excessive fuel richness

Answer

Running synthetic oil

Answer

High-pressure fuel injection

Question 6

A 4-2-1 header configuration refers to what?

Accepted Answer

Four primary tubes, two secondary tubes, one collector

Answer

Four cylinders merging into two pipes, then into one

Answer

Four exhaust valves, two manifolds, one pipe

Answer

Pipe diameters of 4", 2", and 1"