The purpose of Valve Ports is to let exhaust gases out of the cylinder and to let air and fuel mixture into the cylinder!
to Recirculate Exhaust Gases
Nexer heard of ezr valve but an EGR valve is exhaust gas recirculation ,it take some exhaust gases and routes them back into the combustion chambers and reburns them to lower tailpipe emisions.
The purpose of butter fly valve is to maintain one way opening during induction stroke and exhaust stroke.
exhaust valve lead is where the exhaust has a continuous outward pressure to allow the carrott chassis to congregate a new rivet on the downward cylinder. +++ Apparently, 2 people found that tosh, "useful", showing not 1 but 3 born every minute. As to the question, I understand "lead" to refer to the start of the valve opening before top dead centre but I stand to be corrected by someone more knowledgeable on car engine design.
It improves the efficiency of the engine by allowing better exhaust out flow and intake in flow.
The term "Valve Lead" best describes the amount in degrees in which a valve will open before its desired stroke begins The amount of Valve lead can be influential in the amount of air being drawn into the engine. If the inlet valve is opened before the piston has reached TDC on the exhaust stroke it will increase the amount of air going in for the induction stroke. This is also true if the Exhaust valve is opened before BDC on the power stroke the exhaust gases will get a head start in leaving the cylinder allowing more space for inlet gases to enter.
The exhaust valve is always smaller.
To push the lifters up to open the valve to let air in or exhaust out of the combustion chamber.
The purpose is to re-burn any unburned hydrocarbons (fuel) remaining in the exhaust stream after the internal combustion process by putting some of the exhaust gases back through the intake process and scavage for any un-burnt fuel (gas). Hence the acronym EGR - Exhaust Gas Recirculation valve.
The exhaust valve gets hotter than the intake valve.
look at the head with the valve cover off find where the exhaust manifold goes in tha is the exhaust valve or looking at the valves the first one is exhaust then intake then intake ,exhaust,exhaust,intake,intake,exhaust if you have the head off i think the intake valves are bigger than the exhaust