Here Tom no need to make holes in the hull, a panel of the machine compartment allows the exit of large elements, piston, liners, alternator. For a crankshaft, it would be another story. It is usually repaired on site with a portable lathe.
The Fiat marine engines were a bit special, they had a double intake manifold, because they were equipped with turbochargers but also with boost pumps. Quite complicated for the maintenance.
One of the particularities was that the crankcase was completely separated from the cylinders. It was a pure 2-stroke engine, no exhaust valves.
This meant that the piston could be seen going up and down 2.20 meters in its sleeve, very impressive. That's why the piston had a rather high skirt compared to a classic 2-stroke engine like a Burmeister or a Sulzer.
They were very difficult to maintain for us. The two small pipes that we see along the piston rod are called "trombone", they allow the cooling of the piston head, with oil.
Fiat has not been a great builder of large 2-stroke marine engines.
A design that corresponds to this type of engine, here a 2 cylinder, it lacks 6!
The Fiat marine engines were a bit special, they had a double intake manifold, because they were equipped with turbochargers but also with boost pumps. Quite complicated for the maintenance.
One of the particularities was that the crankcase was completely separated from the cylinders. It was a pure 2-stroke engine, no exhaust valve.
This meant that the piston could be seen going up and down 2.20 meters in its sleeve. That's why the piston had a rather high skirt compared to a classic 2-stroke engine like a Burmeister or a Sulzer.
They were very difficult to maintain for us. The two small pipes that we see along the piston rod are called "paperclips", they allow the cooling of the piston head, with water on this engine, with oil on the other brands of 2 stroke engines. Fiat has not been a great builder of large 2-stroke marine engines.
A design that corresponds to this type of engine, here a 2 cylinder, it lacks 6!

An interesting PDF, a good resume:
http://www.jicef.org/pdf_cimac/pdf_cima ... t_2013.pdf
