CRANK CASE EMISSION CONTROL PREPARED BY-D.B.LOKWANI( ) GUIDED BY PRO. A.S.SORATHIYA Sub.- AMPC

Emission Controls 2

emission control system 3 Purpose: control emissions and exhaust from vehicle Turn the harmful gases the car manufactures into harmless ones that don't ruin the environment Problem gases : hydrocarbons (unburned) HC carbon monoxide CO nitrogen oxides NOx sulfur dioxide SO2 phosphorus P lead and other metals Pb

Three (major) Pollutants 4 Hydrocarbons (HC) Un-burnt Gasoline Carbon Monoxide(CO) CO results from the incomplete combustion Fuel Oxides of Nitrogen (NOx) NOx results from air being overheated.

HC 5 HC results from gasoline that is not burned in the engine. This can be due from misfires, burning rich, open loop operation, or excessive cranking.

CO 6 CO results from the incomplete combustion of organic materials. gasoline, kerosene, natural gas, propane, coal, wood, charcoal, diesel fuel, heating oil and almost any other combustible material, such as tobacco and paper.

NOx 7 Nitrogen oxides (NOx) are reactive gases Cause a host of environmental concerns impacting adversely on human health and welfare. Nitrogen dioxide (NO2), in particular, is a brownish gas that has been linked with higher susceptibility to respiratory infection, increased airway resistance in asthmatics, and decreased pulmonary function. Other effects: Principle cause of ground-level ozone formation Contribute to acid deposition, which can damage trees at high elevations and increases the acidity of lakes and streams, which can severely damage aquatic life Contribute to increased levels of particulate matter by changing into nitric acid in the atmosphere and forming particulate nitrate combustion temperature gets above 2,500 degrees F

8 Evaporation from the fuel tank. 5% Blow-by gases which escape from the crankcase % Tail pipe emissions % Carburetor evaporation from the float bowl on old cars.

POLUTION 20 % Crankcase vapors 20% Fuel Vaporization 60% Exhaust 9

Three Ways to Control Pollution 10 1 – Improve combustion 2 – Capture the vapors and re-burn them. 3 – Treat the exhaust.

Ways to Combat Pollution 11 Capture the vapors and burn them PCV EGR Charcoal Canister Improve the combustion Monitor mixture Less Power Treat the exhaust Fewer Emission

WHY 14.7:1 12

Vapor Recovery Type Systems 13 Positive Crankcase Ventilation (PCV) Fuel Tank Vapor Recovery (VVR)

Positive Crankcase Ventilation Uses manifold vacuum to clean blow-by gases from crankcase. Needs a breather tube for fresh air. Needs a PCV valve to regulate the amount of gases entering the intake manifold. 14

PCV Operation The PCV valve has two functions: 1. To regulate the amount of vapor entering the intake manifold at various engine speeds. 2. Prevent damage from backfire. 15

Regulating the PCV Vapor Flow 16 AmountConditionManifoldVacuumBlow-byGases IdleHighVacuumSmallVolume High Speed Low Vacuum LargeVolume

PCV (Positive Crankcase Ventilation System) Uses engine vacuum to draw blow-by gases into the intake manifold for reburning in the combustion chamber. Vacuum or electronic controlled, mounted on the valve cover.

PCV (Positive Crankcase Ventilation System) At idle, high manifold vacuum pulls the plunger for minimum vapour flow (prevents a lean air-fuel mixture). During acceleration, intake manifold decreases. This allows the PCV valve to move to a center position for maximum flow. With engine off, a spring pushes the valve against its seat, closing the valve. A backfire will also close the valve.

PCV Service 19 Replace PCV valve every 3 years/30,000 miles. Clean the breather filter if applicable. The valve can be cleaned also if you don’t want to replace it. Inspect hoses for proper routing and deterioration. Check the air cleaner housing for oil build up. Check PCV system function. 1) Use the PCV vacuum tester. 2) Use the tachometer and look for RPM drop.

PCV Trouble-Shooting Notes 20 Defective PCV system can cause big time vacuum leaks. This can lead to a very fast idle speed or stalling. If the valve or hoses get clogged the vapors back-up into the air cleaner clogging it too and puts oil in the air cleaner housing. A strange problem is if a valve cover gasket starts leaking oil winds up in the air cleaner also.