What are the most common causes which could result in holes (ie penetration) on the exhaust valve of an electronic ME type m/e cylinder?
Understand that your question refers to conventional, liquid fueled engines; not to dual fueled engines.
Several factors (or combination of them) that could lead to a premature deterioration of the condition of M/E exhaust valve spindles (higher burn away rates) and hence shorter overhauling intervals, are the following:
- Improper maintenance and operation of the fuel injectors.
- Prolonged operation at low M/E loads or under circumstances with insufficient scavenge air pressure. Under these conditions the exhaust valve spindle is subjected to higher thermal loads.
- Bad fuel oil quality.
- Improper reconditioning / rewelding procedure of the exhaust valve spindle.
- Inadequate design/material specification of the exhaust valve spindle.
- Wrong timing.
The above are applicable to mechanically (camshaft) and electronically controlled M/E.
Thank you for your answer !