Diesel load and related questions
Something you always read about is diesel load, too little is bad too
much is bad. How do you know what your load is at any given time? Is
there a diesel load meter or gauge ?
Next since once you have a engine and transmission the only variable
related to load is the prop. IF that is the case would this not be
the reason for a variable pitch prop setup?
If you had a variable pitch prop would it make a difference on the
engine load? and would it be worth the cost. ?
If you had a load gauge could you set the prop pitch to the best load
for your situation, and would this relate to fuel economy?
Am I way off base here or is this something that should be seriously
considered when buying a boat or retrofitting a boat.
Hope this is not a dumb question
Jim Meader
mailto:jimmeader@me.comjimmeader@me.com
----- Original Message -----
From: "Jim Meader (by way of Georgs Kolesnikovs)" jimmeader@mac.com
Something you always read about is diesel load, too little is bad too
much is bad. How do you know what your load is at any given time? Is
there a diesel load meter or gauge ?
Jim
What you are looking for is called an EGT - Exhaust Gas thermometer
It measures the temperature of your exhaust gas. Typically it would run
around 700F
Murphy and ISSPRO both make after market gauges you can install. May turbo
chargers and commercial engine manufolds have threaded holes to facilitate
installation
If you had a variable pitch prop would it make a difference on the
engine load? and would it be worth the cost. ?
REPLY
Jim, some designers like Michael Kasten is a big fan of CPP drives. If your
boat weight changes by a considerable amount or the loading varies like in
a tug; a CPP is very useful. In canal running it also makes a difference.
If you do insta la CPP you must install EGT or you risk overloading the
engine and causing damage.
If you had a load gauge could you set the prop pitch to the best load
for your situation, and would this relate to fuel economy?
Yes it does work that way. But the changes in fuel economy is not that
much and you would only realize any savings if you run the boat a lot of
miles every year.
Am I way off base here or is this something that should be seriously
considered when buying a boat or retrofitting a boat.
Its not a dumb question. The answer depends greatly on how and where you
use the boat. But the CPP drive line does have a premium price so unless
you use the boat for a lot of miles every year you may never recoup th
epotential savings.
Arild
A few links on variable pitch props...first one has a cost comparison from a few years ago.
http://www.kastenmarine.com/CPprops.htm
http://www.setsail.com/s_logs/deridder/dragon18.html
http://lists.samurai.com/pipermail/trawlers-and-trawlering/1998-January/000181.html
http://www.boatdesign.net/forums/inboards/propeller-gear-efficency-20810.html
http://lists.samurai.com/pipermail/power-catamaran/2008-January/002354.html
http://lists.samurai.com/pipermail/passagemaking-under-power/2004-December/000119.html
----- Original Message ----
From: Jim Meader jimmeader@mac.com
To: Power Catamaran List power-catamaran@lists.samurai.com
Sent: Monday, June 15, 2009 3:40:51 AM
Subject: [PCW] Diesel load and related questions
Something you always read about is diesel load, too little is bad too
much is bad. How do you know what your load is at any given time? Is
there a diesel load meter or gauge ?
Next since once you have a engine and transmission the only variable
related to load is the prop. IF that is the case would this not be
the reason for a variable pitch prop setup?
If you had a variable pitch prop would it make a difference on the
engine load? and would it be worth the cost. ?
If you had a load gauge could you set the prop pitch to the best load
for your situation, and would this relate to fuel economy?
Am I way off base here or is this something that should be seriously
considered when buying a boat or retrofitting a boat.
Hope this is not a dumb question
Jim Meader
mailto:jimmeader@me.comjimmeader@me.com
Power-Catamaran Mailing List