Repair 7

How Car Headers Work

Carrying Away Engine Exhaust Gases

Headers are typically installed on cars by a vehicle owner seeking to increase the horsepower of his cars engines. Headers are simple exhaust tubes or exhaust pipes that allow for the faster exiting of burned engine exhaust gases. Traditional exhaust manifolds are somewhat restrictive to exiting engine exhaust gases and create a bit of engine backpressure, which reduces engine horsepower and restricts gas mileage. Headers, on the other hand, typically have larger exhaust tubing and special tubing designs that enable exhaust gases to exit a cars engine faster and in greater quantities. This leads to a reduction in engine backpressure and an increase in both engine horsepower and gas mileage.

Bolt Headers to Engine Exhaust Ports

Automotive headers, which take the place of factory-installed exhaust manifolds, simply bolt directly to an engines exhaust ports, which are the openings in a cars engine through which exhaust gases flow out. Headers have flat areas (header flanges) on their exhaust tubing ends that align directly against the side of a cars engine exhaust ports. Header bolts attach directly through the header flanges and create an airtight seal, through which exiting engine exhaust gases travel directly into engine headers.

Funneling Exhaust to Remaining Exhaust Components

As exiting engine exhaust gases flow through a set of headers, these exhaust gases are transported to the remaining components of a cars exhaust system. Headers, besides allowing exhaust gases to exit a cars engine faster and in greater quantities, serve to bridge the gap between the engine and its main exhaust system components. Normally, exhaust gases, after flowing through and exiting a set of headers, travel to a cars catalytic converter, where these exhaust gases are reignited and burned. After traveling through the catalytic converter, exhaust gases travel through a cars muffler and then out of the tail pipe.