MAN DIESEL D2840 LE401piston failures
MAN DIESEL D2840 LE401piston failures
(OP)
The organisation that i work operates these marine engines and is suffering from piston failures at around 1150 hrs total running time.I believe that the problem has not yet been resolved or fully investigated.They are rated at 860 hp at 2300 rpm for this installation
Have any of you out there had similar experiences with these engines ?
Have any of you out there had similar experiences with these engines ?





RE: MAN DIESEL D2840 LE401piston failures
Are they being used as main propulsion of generator sets?
Are they new or refurbished?
Type and state of oil
Injector condition
RE: MAN DIESEL D2840 LE401piston failures
RE: MAN DIESEL D2840 LE401piston failures
Some further info fot you
The engines are used for propulsion in a twin installation running on a 15/40 grade lube oil.
The piston failures are melting of the crown followed by disintegration.I believe that some pistons have been found with cracks on the crown.
RE: MAN DIESEL D2840 LE401piston failures
If you have foulty injectors the Piston Crown temp can increase 150°C-200°C and reach melt down temp.
RE: MAN DIESEL D2840 LE401piston failures
RE: MAN DIESEL D2840 LE401piston failures
If all those things are correct, cooling of the pistons should be investigated. Check whether sufficient oil is sprayed against the piston crown and/or whether the oil passages in the piston crown are not blocked. A black undercrown is a sure sign of insufficient cooling.
A third possibility for the failure might be the type of loading of the engines. If they are idling for prolonged periods and then occasional bursts of full power are needed, it may happen that the temperature rise in the piston is much faster then of the surrounding liners with consequently a temporary mismatch in the clearance between piston and liner.