THERMACTOR System: Description

The Thermactor Exhaust Emission Control system reduces carbon monoxide (CO) and hydrocarbon (HC) content of exhaust gasses. It injects fresh air into the exhaust gas stream as it leaves the combustion chamber, allowing continued combustion of unburned gasses. A typical system consists of the following components: Air supply pump, air by-pass valve, check valve(s), air control valve, air manifold and air hoses.

Individual systems vary in number and type of components depending upon engine size and application, these are as follows: The Managed Thermactor Air (MTA) system uses the same basic components as the standard system, but "manages" thermactor air according to operating conditions. Some models are equipped with Thermactor II system which uses a pulse air valve instead of an air pump. Another system, the Extended Idle Air Bypass System is used to dump secondary thermactor air to the atmosphere. The Thermactor Air Timer system controls emissions that occur on hot starts. It uses a timer to direct carburetor spark port vacuum to the vacuum control valve.