Capt.Bill11
Guru
At some point this just becomes mental masturbation.
Short of taking the transmissions apart there is no real way to tell there condition.
Hours on the engines could mean very little as to how the transmission have been treated.
Engine hours....
- Thread starter NewbieFromNJ
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
At some point this just becomes mental masturbation.
Short of taking the transmissions apart there is no real way to tell there condition.
Hours on the engines could mean very little as to how the transmission have been treated.
Agree. At some point all the hypothetical assumptions render an analysis meaningless. At a sub-micron level I suppose a transmission that has turned 1000 revolutions might have twice the wear as a transmission that only turned 500 revolutions, all other things being equal, but...
Did each operator wait until engine rpm was 700 before shifting? Did each operator change hydraulic fluid at same interval? Did each operator monitor fluid temp? Were the prop shafts properly aligned? Did one operator always have trouble docking and slammed it from forward to reverse 30 times every day after a 1 hour trip? And on and on.
If you don't feel comfortable flipping the coin, hire a mechanic and get a professional opinion.
Nomad Willy
Guru
I'd take the engine (not motor) w 1500hrs.
Tidahapah
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Mate , all you do is get a complete engine survey done on both sets of motors and then make a decision. If they have been looked after , not thrashed or run to slowly then either set would be good. Depending on brand and rating they should be good for 15 to 30000 hrs before overhaul. maybe 50000 hrs if they were Gardners.
I have a mate with a pair of Scania DN11 s in a 61 foot cruiser that have 30000 hrs on them and I think we may get the injectors checked soon. The engines don't use oil and smoke only the slightest when started. have just completed a 1200 NM trip with them and they did not miss a beat.
I have a mate with a pair of Scania DN11 s in a 61 foot cruiser that have 30000 hrs on them and I think we may get the injectors checked soon. The engines don't use oil and smoke only the slightest when started. have just completed a 1200 NM trip with them and they did not miss a beat.
Last edited:
FF
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"How does the transmission play apart in making one’s mind up in choosing which powerplant to go with?""
The reduction gearing in the tranny should have been selected to allow the vessel to cruise at the "sweet spot".
A really hard proposition on boats that will spend 5% of their life at higher speed and the rest at displacement speeds.
The reduction gearing in the tranny should have been selected to allow the vessel to cruise at the "sweet spot".
A really hard proposition on boats that will spend 5% of their life at higher speed and the rest at displacement speeds.
Best answer here! I know that this is what Tony Athens maintains and it makes a lot of sense.
Bruce
That makes sense if you have a solid database of like conditions of use of like engines.
For other more diverse uses like the example posted above, that model begins to fall apart.
The other difference is that modern common rail fuel systems make tracking fuel usage easy, that might change things today...
Bruce
Donna
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2 pages later and still no idea of exactly what we are talking about.
How on earth do you ever make a purchase of anything because the same arguement can be made for everything!
Get the survey's and buy what's cleaner.
How on earth do you ever make a purchase of anything because the same arguement can be made for everything!
Get the survey's and buy what's cleaner.
Agree 100% with your statement.
However in the end it boils down to this.
Everything breaks then we fix it.
The trick me Irish Bro is to get the most bang for our BUCKS! That is the hard part. Sometimes we get lucky, other times we don’t!
Cheers Mate!
H
H me Irish fun time fellow!
That's exactly why it's always good to be Blessed with Irish Luck!
OMG
Just imagine if all the dating clubs began to have similar selection-stat criterion before participants could select a mate!!!
There'd be a lot more single people running around trying to figure out if the gals or guys they were chatting with had too many soft hours or too few hard hours... or maybe, in fact, just way too many or heaven forbid not enough hours at all. :lol:
I say pick the one [engine or person] who have some soft and some hard time on them. Always good to know what your next squeeze can take... or not!
Happy Choose-It Daze! - Art
Beyond the hours in my experience with owners who always run hard is that they just don't have the same concern about engine life. if they run at 17 kn then they probably run faster at times as well. The boat then gets traded after a few years and it becomes the next owners issue.
Personally I avoid things that seem to have been run hard and put away wet. []
Personally I avoid things that seem to have been run hard and put away wet. [
]
FF
Guru
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A problem with engine hours is not only weather the unit was operating at near 100% load factor ,
but the other problem , endless operation as a battery charger , usually to attempt to support an electric fridge of some sort.
A log book would be a great help ,
but the other problem , endless operation as a battery charger , usually to attempt to support an electric fridge of some sort.
A log book would be a great help ,
kev_rm
Senior Member
I have a couple of friends who work for brunswick marine (the owners of mercury).
This is a few years back but their testing of the high performance powerheads from outboards was something like this:
1) Run it at full throttle you go 250 hours until overhaul
2) Run it at half throttle you go 2000 hours until overhaul
That is an exponential factor, obviously not just the revolutions.
Keep in mind these are lightweight 100hp+/liter engines.
This is a few years back but their testing of the high performance powerheads from outboards was something like this:
1) Run it at full throttle you go 250 hours until overhaul
2) Run it at half throttle you go 2000 hours until overhaul
That is an exponential factor, obviously not just the revolutions.
Keep in mind these are lightweight 100hp+/liter engines.
Nomad Willy
Guru
Sunchaser,
"Not revealing" indeed. Had a runaway about a year ago. Had leakage and lots of fuel (or water) in the crankcase. Started the engine after an oil change but forgot the oil .. shut down as soon as rattling noise started and it's been fine ever since or how many would even mention any of the above. Perhaps a lot of engines experienced this type of thing, or even more.
As far as engines go I have the greatest faith in high level analysis. Compression and/or leak down tests. Partial disassembly fine. Spend some money. Almost any defect can be derected ... or can it? But a tech minded and equiped and with extensive experience mechanic should be able to uncover the most defects in an engine. Far far more than an hour meter. Perhaps they have cameras like the medical people and can snake one down into the cylinder and thake a vid of the cylinder wall.
My last comment on hour meters is that there's absolutely no telling if the number you see is reality. Far as I know.
