How to remove and piston removal of 2 stroke and 4 stroke engine ?
To remove piston we have to prepare some documents and preparations related engine.
Always wear Protection protective equipment.
piston removal of 4 stroke engine
if you read the post Decarb of auxiliary engine, you definitely know how to remove piston. if you have not read then here written below the full information and process to remove piston. So let us start.
First tool box meeting and preparations of all the tools required for removal. Risk assasement and tell about the procedure to person involve. Go through manual.
Come to the auxiliary engine platform and start the another generator after with taking proper precautions. Wait for five minute and check all parameter are ok. after that come to ECR and take on load and shut off the generator which need to be work.
Start the priming pump and let it cool down. After half an hour stop the priming pump. Open the indicator valve. Start opening the crankcase door of all unit one by one. After opening let it cools down for some times.
Now let us start the procedure.
shut of all the line
- Fuel oil inlet and outlet valve
- jacket water valve
- sea water valve
- air starting valve
First remove all the piping system attach to the cylinder head.
- Air scavenging manifold
- exhaust manifold
- fuel pipe
- jacket water pipe
- Air starting line
Now open the top cover and side cover of cylinder head.
- Start dismantling rocker arm bridge, remove the push rod.
- open the tightening nut of fuel injector and remove support. To remove fuel injector there is a special tool looks like crow bar in daihatsu diesl engine. If that tools is not available then we can remove fuel injector with the help of crow bar.
- Finally remove the cylinder head.
Now main work start
Clean the surface of piston and put some water in the hole where lifting tools fit.
Take piston on TDC. Put eye bolt or lifting tools on piston.
now open the nut of crank pin or connecting bottom end bearing.
Suggested :- Are you inetrested in knowing the procedure how to remove bottom end bearing and take its clearance.
Depending upon the engine, to remove nut of crank pin some engine require torque spanner and some engine require hydraulic tools.
In daihatsu diesel engine i used torque spanner to open nut.
For hydraulically fitted nut, put the hydraulic nut on bolt and tighten it. After tightening it loosen it by one turn in opposite directions.
purge the hydraulic hose and put the hose on hydraulic nut. Start increasing pressure on it. When pressure reaches upto 60 bar, Stop increasing the pressure. With the help of tommy bar open the nut. Release pressure and remove hydraulic hose.
Remove nut. With help of pulley ;ift the piston and take it on workshop for overhauling.
Piston removal of 2 stroke engine
Inform the company and take imobilasation certificate and inform port that main engine not ready for this hours. Risk assasement with person involve and go through manual. Prepare all tools. Also prepare enclose space entry. Shut the main lube oil pump and proper ventilation of crankacse then enter for removal of nut of foot of piston rod.
Now, shut down the engine and locked the air starting valve. Now open the indicator valve and do not forget to engage the turning gear.
Close the exhaust valve for exhaust valve if your engine is loop or cross type no need.
Now disconnect all the pipe attach with the cylinder head and protect all the openings by covering it with cloth. Close the inlet and outlet of jacket water system and drain jacket water. Fuel valve also closed and disconnect the fuel injection pipes that is high pressure pipes.
Now remove the plastic cap of cylinder head bolt and clean the bolt.
Clean the hydraulic nut and surface near it.
Install the Spacer and then tight hydraulic nut and loosen if by half turn and purge the hose of hydraulic pipe. and connect it to nut and increase pressure. Increase pressure upto 1020 bar. If pressure reaches to 1020 bar then Loose the nut with tommy bar.
Release pressure and remove hydraulic hoses and nut. Now our cylinder head is ready to lift. Put eye bolt on cylinder head. With engine room crane lift slowly. Lift it and put it on Wooden block.
Now remove the Scraper or polishing rings which is fitted in top of liner. Clean the parts of top part of piston crown and liner.
Take the caliberation of cylinder liner. Calliberation taken by template with the help of internal micrometer at port or stbd and fwd or aft. Noted down and compare the wear rate with previous one.
Now with turning gear turn the engine so that piston is at TDC.
Connect hydraulic tenstioning nut and increase pressure upto 1020 bar. Noe piston rod is free. Put distance piece on the footb of piston. This distance piece did the work of pushing gland box and also help in protecting damage of scraper rings.
Open the internal of gland box. Now put lifting tools on piston and lift the piston with the help of engine room crane. Meanwhile cover the stuffing box to protect from dirt. Lower the piston rod on hole provide on the cylinder head platform.
This is all bout removal of piston of 2 stroke engine.
Now we have to clean all the parts of piston. Remove the piston rings with the help of rings extractor . and clean the grooves and take all clearance of piston rings. If it is required to change rings then change it.
Note: – To remove piston we have to open the cylinder head and bottom connecting rod in the case of 4 stroke and piston foot in the case of 2 stroke.
This is all about removal of piston procedure. But if you have to remove the stuffing box or doing overhaul then you have to remove piston.
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