Some relevent questions about starting air valve- 1. What is the function of vent? Smooth operation of the v/v if in case any pressurised air leaks past the piston 2. Function of balance piston? Balance the valve and keep the valve in close position when pilot air not supplied 3. Why balance piston dia small […]
How do you check the cylinder starting air valve for leak? Finished with engine Get propeller clearance from bridge Indicator cocks must be open Unit to be tested to be brought to TDC Turning gear must be disengaged for test Control air to starting air distributor must be SHUT Automatic starting air valve must be […]
Possible causes of exhaust valves Burning/Failing Prematurely Mainly there are 2 possible reasons- Source of fuel Fuels of Venezuelan origin tend to have higher vanadium content causes high temp. corrosion Vanadium is in soluble form and hence cannot be reduced by centrifuging or filtration Keep the operating temperatures below 500 0C to avoid this problem. […]
Some relevant questions on tappet clearance and v/v What position to carry out tappet clearance Answer: In a 4-stroke engine, the tappet clearance is carried out at TDC of the combustion stroke There are 2 TDC positions for every cycle How to differentiate between 2 TDC position in 4 strock? At the combustion stroke, the […]
What is the procedure for taking tappet clearance after a major overhaul? After major overhaul: After all the components are assembled and cylinder heads are mounted and tightened, place the rocker arms and tighten open the jacket cooling water system and check for leaks If no leaks, then activate the jacket water warming/heating system Fill […]
What happens if there is too much clearance? If there is too much clearance, the valves will open late and close early. ‘Knocking effect’ The valve opening period is very much reduced What happens if there is too little clearance? If there is too little clearance, the valves will open early and close late. There […]
Tappet clearance is necessary because: When the engine is running under normal operating conditions, the inlet and exhaust valve spindles get heated up and tend to expand or elongate When this happens and if there is no tappet clearance, the valves will be unable to fully close