Difficulty: Easy
Correct Answer: regulates the pressure and flow of engine oil supplied to the cylinder head mechanism and related passages
Explanation:
Introduction / Context:
Modern engines meter oil to the top end (camshaft, lifters/followers, valve train) using calibrated restrictions. Knowing what an oil control orifice does helps technicians diagnose top-end noise, low-pressure warnings, and oil starvation issues.
Given Data / Assumptions:
Concept / Approach:
An orifice is a hydraulic restriction that controls flow rate for a given pressure differential. By limiting flow to the head, system pressure in the main gallery is maintained while ensuring sufficient lubrication of the valve train. Filtration is performed by the oil filter, not the orifice; misting is handled by splash and windage, not by a metering hole; and drains rely on gravity via dedicated return passages rather than being ‘‘accelerated’’ by the orifice.
Step-by-Step Solution:
Identify the component: a small, precise hole in the feed line or banjo/jet.Recall fluid principle: flow through an orifice depends on pressure drop and area.Relate to engine needs: maintain gallery pressure while supplying adequate top-end oil.Select the option describing pressure/flow regulation to the head.
Verification / Alternative check:
Service manuals specify ‘‘orifice jet’’ sizes and warn that enlarged jets lower system pressure and increase consumption, which corroborates the metering function.
Why Other Options Are Wrong:
High-speed return is not an orifice function; oil misting is incidental; impurity removal is the filter’s role.
Common Pitfalls:
Drilling orifices larger during rebuilds; misdiagnosing low pressure as pump failure when a missing jet is the cause.
Final Answer:
regulates the pressure and flow of engine oil supplied to the cylinder head mechanism and related passages
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