Reply
 
Thread Tools Display Modes
 
Old 11-07-2013, 04:29 PM   #21
Guru
 
SomeSailor's Avatar
 
City: Everett, WA
Vessel Name: Honey Badger
Vessel Model: 42' CHB Europa
Join Date: Oct 2011
Posts: 784
Quote:
Originally Posted by obthomas View Post
Reverse at high RPMs is also a good test of your shaft coupling shear pins and set screws. If you pull your shaft from the coupling its best to do it at the dock.
When I surveyed mine, I noticed stainless clamps on each shaft. A foot or so forward of each seal. When I was looking at them, the surveyor said that was good trick to keep your shaft in the boat if you sheared one. The drag can pull them backwards and out of the boat otherwise.
__________________
Advertisement

SomeSailor is offline   Reply With Quote
Old 11-07-2013, 04:40 PM   #22
Guru
 
boatpoker's Avatar
 
City: Port Credit
Country: Ontario
Vessel Name: DIRT FREE
Vessel Model: Benford Fantail 38
Join Date: Sep 2012
Posts: 2,012
Quote:
Originally Posted by SomeSailor View Post
When I surveyed mine, I noticed stainless clamps on each shaft. A foot or so forward of each seal. When I was looking at them, the surveyor said that was good trick to keep your shaft in the boat if you sheared one. The drag can pull them backwards and out of the boat otherwise.
That's why I keep my spare anodes there.
__________________

boatpoker is offline   Reply With Quote
Old 11-07-2013, 04:41 PM   #23
Guru
 
boatpoker's Avatar
 
City: Port Credit
Country: Ontario
Vessel Name: DIRT FREE
Vessel Model: Benford Fantail 38
Join Date: Sep 2012
Posts: 2,012
Quote:
Originally Posted by manyboats View Post
During periods of non-use I like to crank the engine twice for two 10 second periods every 30 days. Distributes lube oil, exercises rings and oil seals.
I do the same thing with the throttle solenoid activated so it won't start.
boatpoker is offline   Reply With Quote
Old 11-07-2013, 06:29 PM   #24
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,723
Poker,
Mine won't start anyway w/o the glow plugs but wish I had a compression release.

Everybody seems to think an engine is at operating temperature if the coolant is up. NOT SO. Basic parts like pistons and valves are still relatively cool. That's the core of the issue w under loading. Idling at the float in or out of gear dosn't mean you have a significant load. My Mitsu warms up to 185 degrees coolant temp in just a few minutes in neutral. Running at a 50% load will probably do the trick but that's far cooler than a 75% load. And I'm not talking 50 & 75% of throttle or rpm either. 50% load is at whatever rpm your engine burns half of it's maximum fuel consumption at WOT.

If it's too inconvenient to do that I just crank the engine a bit. And it is inconvenient as I'm blocked on the hard.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 11-07-2013, 06:36 PM   #25
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
No problem using boats all year here so it doesn`t arise for Aussies.
But its a good point. What is the maintenance practice for back up generators, like at hospitals, which have to be kept ready to produce amps instantly?
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 11-07-2013, 07:50 PM   #26
Guru
 
boatpoker's Avatar
 
City: Port Credit
Country: Ontario
Vessel Name: DIRT FREE
Vessel Model: Benford Fantail 38
Join Date: Sep 2012
Posts: 2,012
[QUOTE=manyboats;190156]Poker,
Mine won't start anyway w/o the glow plugs but wish I had a compression release.

Everybody seems to think an engine is at operating temperature if the coolant is up. NOT SO. Basic parts like pistons and valves are still relatively cool. That's the core of the issue w under loading. Idling at the float in or out of gear dosn't mean you have a significant load. My Mitsu warms up to 185 degrees coolant temp in just a few minutes in neutral. Running at a 50% load will probably do the trick but that's far cooler than a 75% load. And I'm not talking 50 & 75% of throttle or rpm either. 50% load is at whatever rpm your engine burns half of it's maximum fuel consumption at WOT.
QUOTE]

I totally agree with all of these points but many on this forum do not, according to posts on similar threads.
boatpoker is offline   Reply With Quote
Old 11-07-2013, 07:54 PM   #27
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,922
Funny ....NONE of the manufacturer manuals I have read give a rat's rear end about anything but coolant temp...and they don't care if the engine is stone cold except don't go to full power until warmed up...which some of us NEVER do...some of us never get over 50% power...

If it's a big deal to you and you don't get that most people have engines that keep going despite these crazy worries...use an IR temp gun and shoot the oil line temps...

Can't believe the gross misrepresentation some keep proliferating....
psneeld is offline   Reply With Quote
Old 11-07-2013, 09:01 PM   #28
Guru
 
boatpoker's Avatar
 
City: Port Credit
Country: Ontario
Vessel Name: DIRT FREE
Vessel Model: Benford Fantail 38
Join Date: Sep 2012
Posts: 2,012
I don't see any "Gross misrepresentation" just a couple of guys describing their own practices and beliefs.
boatpoker is offline   Reply With Quote
Old 11-07-2013, 10:20 PM   #29
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,922
Quote:
Originally Posted by boatpoker View Post
I don't see any "Gross misrepresentation" just a couple of guys describing their own practices and beliefs.
Exactly....
psneeld is offline   Reply With Quote
Old 11-07-2013, 10:54 PM   #30
Guru
 
boatpoker's Avatar
 
City: Port Credit
Country: Ontario
Vessel Name: DIRT FREE
Vessel Model: Benford Fantail 38
Join Date: Sep 2012
Posts: 2,012
Quote:
Originally Posted by psneeld View Post
Exactly....
Glad you agree ... don't think that's happened before
boatpoker is offline   Reply With Quote
Old 11-07-2013, 11:41 PM   #31
Guru
 
koliver's Avatar
 
City: Saltspring Island
Country: BC, canada
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 2,174
I am firmly in the "never" camp.

Unless I can take Retreat out for a run, I never start the engine just to run it. In the winter I like to feel the icy wind in my face, check out what interesting things are happening in the harbour, and as a bonus, get the engine good and warm. If I can't, I leave it alone. My Hot water tank and charger keep the ER from freezing. The outside water never freezes here, so I don't need to do anything else.
koliver is online now   Reply With Quote
Old 11-08-2013, 06:26 AM   #32
Guru
 
timjet's Avatar
 
Join Date: Apr 2009
Posts: 1,905
Just curious for those of you that have the Cummins B series; my engines will achieve 180 deg at the dock in neutral in about 15 minutes. Not necessary to put a load on them.
Am I bringing them up to operating temp?
__________________
Tim
Tampa Bay
Carver 355 ACMY Twin Cummins Diesels Sold
timjet is offline   Reply With Quote
Old 11-08-2013, 06:32 AM   #33
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Quote:
Originally Posted by manyboats View Post
Everybody seems to think an engine is at operating temperature if the coolant is up. NOT SO. Basic parts like pistons and valves are still relatively cool. That's the core of the issue w under loading.
Valves are probably the most difficult component to cool, they are directly exposed to combustion gases - the exhaust valve lives in the path of a blowtorch. They are very low mass, they heat up nearly instantly. The only way valves are cooled is by conduction to the coolant in the head ... where do you think coolant heat comes from?

The pistons are also directly exposed to the combustion gases as are the cylinders. The pistons are mostly cooled by heat conducted through the rings to the cylinder wall ... which is the other major source of heat that goes into the coolant.

Problems that might in some rare cases be created by low load operation of small propulsion engines are related to many issues but cooling is probably the least of them.

The main reason you shouldn't run the engine at high power or rpm when cold is because oil viscosity is probably at its highest and this can create lubrication problems in some cases. If the engine is not ice cold or uses a multi-viscosity lube oil this is probably not an issue.
RickB is offline   Reply With Quote
Old 11-08-2013, 06:35 AM   #34
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Quote:
Originally Posted by timjet View Post
Just curious for those of you that have the Cummins B series; my engines will achieve 180 deg at the dock in neutral in about 15 minutes. Not necessary to put a load on them.
Am I bringing them up to operating temp?
Oil temperature is your best guide. If the oil is in the normal operating range then all is good. There is more to it than just temperature though which begs the question "what are you hoping to achieve by idling at the dock in neutral?"
RickB is offline   Reply With Quote
Old 11-08-2013, 06:46 AM   #35
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,922
There are "other reasons" to run an engine other than "just warming up the engine"...not all may agree or have the same reasons..but for some...they have theirs.

Mine are...
1. unless taking the water pump impeller out...it exercises the rubber.
2. helps drive moisture out of bolt on components and wiring
3. does circulate oil lube in both engine and gear box
4. provided oxygenated water to stuffing (shaft upon last removal had significant pitting)
5. lets me know if thru hulls have growth
6. knocks growth off of running gear, rudder and parts of the hull.
7. lets me know what systems are working or not (this go around it let me know my starter was having issues so I could get it repaired long before my quickly approaching 4 month cruise)...also keeps me satisfied that if I need to move the boat in a hurry...I can because waiting for the assistance towing guy in an emergency would be a waste of time because that would be me.
psneeld is offline   Reply With Quote
Old 11-08-2013, 07:10 AM   #36
Guru
 
motion30's Avatar
 
Join Date: Jan 2010
Posts: 740
Cool

Quote:
Originally Posted by KJ View Post
Michael,
No, not this winter. I might drive down to the Keys for some diving if I get cabin fever.

I do plan on heading south next fall/winter (2014). I’d like to leave here around the middle of Oct. I want to spend a week or so on the hook at Cumberland Island. We really enjoyed our visit there last May, but could only stay for two days. When we get to Lake Worth we’ll start looking for a window. As soon as a good one opens, we’ll make the jump over to the Bahamas and spend the rest of the winter there. If nothing opens up right away, we’ll just keep heading south and hang out in Marathon to wait it out.

Hope to see you down there again.

What are your plans? KJ



Avalon & Bay Shack at Key West
Hi Ken hope all is well . Make sure you let me know when you come here. In the interest of keeping my motors healthy, I am heading for the keys in a week or so
motion30 is offline   Reply With Quote
Old 11-08-2013, 10:26 AM   #37
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,723
Rick what is the temperature of compustion gases in the combustion chamber at idle in a diesel engine and what is it at heavy loads?

And yes I agree EGT and oil temp should be the yardstick of real engine temp.

Oh and another thing what would the coolant temp be at idle w the thermostat removed?
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 11-08-2013, 10:54 AM   #38
Guru
 
timjet's Avatar
 
Join Date: Apr 2009
Posts: 1,905
Quote:
Originally Posted by RickB View Post
There is more to it than just temperature though which begs the question "what are you hoping to achieve by idling at the dock in neutral?"
Well that's a good question and psneeld addressed some reasons for doing this.
It does seem that those that use their engines a lot provided they take care of them have less trouble. But that's a catch 22, you have to take of them if you use them a lot.

In South FL there are a number of snow birds that haul their boat for 8 months out of the year. It would be interesting to find out if they have more engine issues than someone that uses theirs year round.
__________________
Tim
Tampa Bay
Carver 355 ACMY Twin Cummins Diesels Sold
timjet is offline   Reply With Quote
Old 11-08-2013, 11:02 AM   #39
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Quote:
Originally Posted by manyboats View Post
And yes I agree EGT and oil temp should be the yardstick of real engine temp.
EGT is an indicator of load. It can also be an indicator of fuel quality or other combustion conditions depending on when and where and a number of other operating parameters. Very high EGT might be a harbinger of future or potential overtemp problems but EGT is never an indicator of "real engine temperature."

Quote:
Oh and another thing what would the coolant temp be at idle w the thermostat removed?
How long is a piece of string?
RickB is offline   Reply With Quote
Old 11-08-2013, 11:44 AM   #40
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 13,723
Quote:
Originally Posted by RickB View Post
EGT is an indicator of load. It can also be an indicator of fuel quality or other combustion conditions depending on when and where and a number of other operating parameters. Very high EGT might be a harbinger of future or potential overtemp problems but EGT is never an indicator of "real engine temperature."

How long is a piece of string?
Heat is a direct measurement of work being done as diesel engines are heat engines. Load is work. Work is heat. A diesel won't warm up w/o a load.

I take it that your cute riddle "How long is a piece of string?" to mean a wide range of temps. Not so. The answer is ... very cool. Coolant temp at idle isn't an indication of work being done it's an indication of how the thermostat is working. Coolant w/o the thermostat could be as low as 100 degrees .. I don't know but it would be so low no one would consider their engine warmed up to operating temp w/o the thermostat. My whole point here is to point out that the coolant temp is largely a false indication of overall engine temp. A diesel mechanic told me a long time ago one probably couldn't even fry an egg on the exhaust manifold of an idling diesel.
__________________

__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 04:46 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012