skipperdude
Guru
Thanks RT. Gave me a good chuckle.
SD
SD
My advice - pick out the boat you like based on the boat's design, features, and construction. Then have a competent mechanic analyze the engine.
Greetings,
Mr. SD. Cat man huh? Good thing your not this.....then again....
While the engine is a large item in a trawler , most folks will not purchase a boat based on the engine.
Some will avoid a specific brand (like Volvo) but few will base the selection on what is installed.
In most slow cruisers the ability to operate at a small percentage of the rated power is a plus.
And active ongoing support from the engines marinizer is a big plus.
If you are looking at previously owned boats, the brand name of the engine will often be less important than how well it has been maintained. On a much older boat, do ask around about parts availability. Some engines that were in common use a while back, (the Cummins "triple nickel" comes to mind as an example) might have been fabulous engines in their day, and maybe still are if well maintained, but eventually something will break and parts availability can be an issue.
I'm a huge fan of Perkins. Just personal preference and experience. There are many other good choices as well.
If hoping for a long lifespan from your engine(s), one of the old "isms" that seems to be consistently valid is the 2:1 ratio. See if you can find an engine that displaces two or more cubic inches for each HP developed. (Example would be a 354 cu in inline six producing 165 HP). Especially some of the newer engines rely on running much higher RPM to achieve rated HP. Most of those legendary 15, 20, 25,000 engines are slower turning.
Not sure the 2:1 thing is valid with todays modern engines based upon what i see in the auto industry in which its closer to 1:1 and they seem to live long trouble free lives. All turbo's and last hundreds of thousands of miles. Of course we wont know for years if this will hold true for the marine versions
My advice is to check for parts availibilty for any engine you are looking at. Some manufacturers do not support their older products, Volvo in particular.
Can you think of any disadvantage in choosing a higher displacement to HP ratio, when available?
Are you willing to bash Chevrolet for no longer supporting the Corvair?
Sure...lighter, smaller, more efficient...need I go on????
We're looking at slow trawlers in the 35 to 45 ft range so I guess i'm looking for opinions on engines that would be appropriate for a boat of that size.
thats funny but true. reminded me of one time i paid a guy almost $1000 to fix an engine and it still was the same as when he started. He said another $500 would fix it. I didnt have $500 but i had a six pack and bought a book, some wrenches were applied and with the help of the cardboard six pack which i used to make a gasket the engine was fixed and ran for years like that trouble free. Cost for the repair, one six pack and elbow grease. I wuz 21 at the time. Beer can be a live saverGood engine / Bad engine .
Well after thousands of hours using engines.
There are days that end with GOOD ENGINE , GOOD ENGINE!
Then there are days that just never seem to end BAD ENGINE BAD !
Most engines seem to need a thump from a very big hammer at some point in there life.
Some folk carry a big stick around. Yet for me that "pollish socket set" a very big hammer and some epoxy along with some life saving beer seems to get me home most of the time.
YMMV.
I was referring to engine longevity, the advantage originally claimed for the old 2:1 standard. Even *if* some smoking hot little diesel revved up to 3500 or more is "lighter, smaller, more efficient"- is it likely to outlast, or last as long, as a larger heat sink running at 1800 to 2000? Yanmars have proven higher speed doesn't necessarily mean higher maintenance or shorter life...
From the longevity aspect, I fail to see any advantage to a high revving small engine over a slower revving larger engine rated at the same HP, and I see no disadvantage in choosing the larger engine. Unless you don't have or want more room.
It would be my opinion that engine weight in a true trawler application, running near hull speed, isn't as crucial as with a ski boat or a day cruiser. True unless you have a pocket cruiser or engine configuration where weight distribution could be enhanced by a smaller engine...as in cockpit mounted to v-drives...etc..etc...
Chuck,
Nobody should care about how long an engine lasts or what rpm it is intended to run at. At least 99% of us will never wear out the engine w the shortest engine life expectancy. Lots of engines get killed but not worn out. So what does it matter how long some guru says it's supposed to last or what rpm it's run at. Makes no never mind.
Certainly nobody is required to care. If the smaller high-rev diesels eventually develop a reputation as "2000 hour engines" or "2500 hour engines", and you put 150-200 hours per year on your engine for a decade before selling it it might have an impact on your resale value. Once again *if* the smaller high-rev diesels eventually develop a reputation....
We know what reputation the traditional, slower turning engines have developed and a 2000 hour diesel engine is no big deal, (pending oil analysis, etc). But try to sell a gas boat with 2,000 engine hours. A gas engine is going to be considered worn out at 2,000 hours by a lot more people than currently considering a diesel worn out with the same usage.
Until there is a widespread consensus about durability of the smaller engines, resale is a possible (not saying certain) concern.
Somewhere there are some pretty solid numbers about the relationship between the amount of fuel that has been pumped through a cylinder and its life expectancy without a rebuild. I'll try to find that. It's supposedly even more accurate that engine hours alone.
Certainly nobody is required to care. If the smaller high-rev diesels eventually develop a reputation as "2000 hour engines" or "2500 hour engines", and you put 150-200 hours per year on your engine for a decade before selling it it might have an impact on your resale value. Once again *if* the smaller high-rev diesels eventually develop a reputation....
We know what reputation the traditional, slower turning engines have developed and a 2000 hour diesel engine is no big deal, (pending oil analysis, etc). But try to sell a gas boat with 2,000 engine hours. A gas engine is going to be considered worn out at 2,000 hours by a lot more people than currently considering a diesel worn out with the same usage.
Until there is a widespread consensus about durability of the smaller engines, resale is a possible (not saying certain) concern.
Somewhere there are some pretty solid numbers about the relationship between the amount of fuel that has been pumped through a cylinder and its life expectancy without a rebuild. I'll try to find that. It's supposedly even more accurate that engine hours alone.
Not sure where that bad info came from or how old it is....most modern marine engines nowadays are going much longer....inboard, outboard, gasd, diesel...etc...etc...
We routinely put over 5000 hours on gas inboards in the assistance towing fleet and beat the livin' crap out of them compared to rec boaters.
The trouble with just using hours is that itn is of little relavenvce to how old all the expensive parts that are bolted on to it or how it's been used/abused.
Chuck,
Nobody should care about how long an engine lasts or what rpm it is intended to run at. At least 99% of us will never wear out the engine w the shortest engine life expectancy. Lots of engines get killed but not worn out. So what does it matter how long some guru says it's supposed to last or what rpm it's run at. Makes no never mind.
Not sure where that bad info came from or how old it is....most modern marine engines nowadays are going much longer....inboard, outboard, gasd, diesel...etc...etc...
We routinely put over 5000 hours on gas inboards in the assistance towing fleet and beat the livin' crap out of them compared to rec boaters.
The trouble with just using hours is that itn is of little relavenvce to how old all the expensive parts that are bolted on to it or how it's been used/abused.