T&T: Pyrometers and CP wheels (was ? More on diesel fuel consumption )

[Truelove39@aol.com]

Nice post, Larry.
 
Exhaust temperature has been used for years as the best indicator of load,  
and anyone with a CPP should have a pyrometer, preferably at the  helm. Maximun 
temps are available from the manufacturers. We have a  main engine pyrometer 
in the ER panel which we keep an eye on in  severe headsea/wind conditions and 
slow accordingly if needed. However, this  assumes that everything is in good 
shape; a bad injector nozzle can lead to  after-burning and a high exhaust 
temperature even if the engine isn't  overloaded.
 
Regards,
 
John
"Seahorse"
 
 
<big snip>
 A CPP can increase the 
blade pitch at lower rpms to use the full  engine power available at that rpm 
point. Since both gasoline and diesel  engines are more efficient when loaded 
to 
about 80% of their maximum power  output, the CCP can gain a few percentage 
points in efficiency.. The  downside is that it is possible to overload the 
engine 
if you are not  careful. It is difficult to damage an engine with a correctly 
specified  fixed pitch prop since the prop serves as an rpm  limiter.