turbos10

There are many interesting factoids about those engines. They seem to defy physics.....or at least conventional(wrong many times) wisdom.

dieselcamp

He was also asking why the pistons do not melt, most of the time if high EGT's are sustained the piston expands to fast and scores the skirt and ciylinder wall, this is what happens when a piston cooling nozzel is dammaged, you will find damage on the cylinder that has a failed nozzel. This can also be seen when you have a fuel nozzel overfueling, or when you have a broken exhaust rocker and if it is driven too long, which is common on C15 accert CAT engines.

35" 05'

ok how many answers do we have going on here? Yes aluminum melts at 1200ish deg. The crowns and craters of the piston are coated with a "heat resistant substance" so to speak. This is why you need to be very careful while removing and cleaning a piston NOT to scratch the surface because it WILL eventually burn right through without the coating on. Not possitive on the formula but diesel has to be 750* to ignite. Ur egts are 300* at idle. Do the ratio to that and when your egts are 1600* Not gonna be very acurate but gives an idea how hot the combustion gets. Yes oil is sprayed to cool off the piston but does not effect the combustion chamber temps while igniting. Boost mainly helps to get the gasses out of the chamber to fill back up with clean air as fast as possible. Valve overlap also helps with this in getting as much Clean air in. Different cams, different degrees of overlap. hope this helps