Quote:
Originally Posted by mcarthur
Thanks Lepke.
Could you explain more about natural aspiration engines not needing EGT?
We have two Perkins M135's - big, heavy, NA's.
I was debating whether to go the band style EGT (Borel) or the probe/insertion to try and detect coolant loss AND something catastrophic happening meaning sudden high exhaust temps. It sounds you don't feel a NA engine will need that EGT information?
|
I've run lots of engines with pyrometers. Almost all were turbo. Naturals under usual setups don't create high enough EGTs to harm the engine. If you have pyrometers, they're handy for comparing what's happening inside the cylinder. If you don't have them, a temperature gun on the exhaust port is just as useful. Something catastrophic that would cause extreme EGTs would be a burnt injector tip that would also be obvious by the black smoke following the boat. Most yacht engines don't send a lot more fuel thru a bad tip. The smoke is because the fuel wasn't atomized and is still burning as it exhausts.
For example, my Detroits at the end of a long run at full rated hp, don't make 600°F EGTs. POs ran them 300rpm higher on yearly trips from Canada to Mexico w/o problems. When I rebuilt the engines there was no heat damage, just wear from decades of operation. But Perkins, Volvos or Lehmans aren't Detroits, so 80% of hp is a good rule.
A low oil pressure alarm and high coolant temperature alarm is enough for me.