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What is the purpose of valve overlap?

Anonymous

∙ 12y ago

Updated: 4/28/2022

Overlap allows the exiting exhaust gases to help pull the intake air/fuel charge into the cylinder. This increases volumetric efficiency/cylinder filling especially at lower rpms, when intake charge velocity is low (torque builds quicker). More overlap/Narrower LSA(lobe separation angle) usually results in a peaker powerband/higher Tq/Hp #s. Downsides are: some bled-off cylinder pressure, contamination intake charge(part throttle especially), weaker vacuum signal, rougher idle, narrow powerband, poor part throttle running and higher emissions due to both valves being open.

Wiki User

∙ 12y ago

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Related Questions

What is purpose of valve overlap?

It improves the efficiency of the engine by allowing better exhaust out flow and intake in flow.

Where is the EGR valve on a 1997 Hyundai Elantra?

Does not have one. The engine uses cam overlap to achieve the effect of the EGR valve.

What does the term valve overlap mean?

Valve timing overlap is the time when both exhaust and intake valves are open most engines with catalytic converters require valve overlap in order to send a small amount of raw fuel/ air mix to the converter's. An "open cam" has valve overlap a "closed" cam does not

What is the purpose of the valve in an engine?

The purpose of the valve spring is to maintain contact between the components in the valve train, so the valve motion will follow the cam profile.

What is the purpose of a valve spring in an engine?

The purpose of the valve spring is to maintain contact between the components in the valve train, so the valve motion will follow the cam profile.

What is valve overlap?

Valve overlap occurs in a four-stroke engine at the end of the Exhaust stroke and at the beginning of the Induction stroke; and is when both the exhaust and inlet valves are open at the same time. At the end of the Exhaust stroke, the Exhaust valve is closing and the Inlet valve is starting to open in preparation for the induction of fuel and air into the cylinder. It is common knowledge that in vehicles that cannot alter the valve timing, the Inlet valve opens approx 6 degrees before top-dead-centre and the Exhaust valve closes at 9 degrees after top-dead-centre

When the intake and exhaust valves are both open at the same time that length of time is called?

Valve overlap.

What is the purpose of a valve tappet?

To move the valve down as the camshaft rotates.

What is the purpose of valve ports?

The purpose of Valve Ports is to let exhaust gases out of the cylinder and to let air and fuel mixture into the cylinder!

What is the purpose of geyser pressure valve?

The purpose of a pressure relief valve in a geyser is to release the pressure created inside due to evaporation of water.

What does a overlap valve do?

send a small amount of raw fuel/air to the catalytic convertor,which increases the efficiency of the operating engine.

What is the purpose of the water shut off valve cap and how does it help in maintaining the functionality of the valve?

The purpose of the water shut off valve cap is to protect the valve from dust, debris, and damage. It helps maintain the functionality of the valve by preventing these external elements from entering and potentially causing the valve to malfunction.

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