摘要 |
A vacuum reducer valve is used in the distributor vacuum advance circuit in conjunction with an engine overheat detection three way valve which normally applies spark port vacuum to the distributor vacuum advance actuator. When the engine overheats, the spark port signal is blocked and manifold vacuum is applied to the distributor vacuum actuator. The manifold vacuum, however, averages three to four inches of mercury vacuum higher than the spark port vacuum thereby necessitating the use of a vacuum reducer valve in series with the manifold vacuum line to the distributor to avoid excessive spark advance.
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