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Carlos
09-06-2000, 05:01 PM
Any hints on what to consider when deciding to change the engine? I recently bought a 30' custom made 1954 cruiser which originally had an inboard but was changed for a 15HP Mariner Outboard. I am thinking on changing back to a diesel inboard but first thought on inquiring of past experiences. The boat weighs over 5 tons and we only do coastal cruising (at sea).

Carlos
09-06-2000, 05:01 PM
Any hints on what to consider when deciding to change the engine? I recently bought a 30' custom made 1954 cruiser which originally had an inboard but was changed for a 15HP Mariner Outboard. I am thinking on changing back to a diesel inboard but first thought on inquiring of past experiences. The boat weighs over 5 tons and we only do coastal cruising (at sea).

Carlos
09-06-2000, 05:01 PM
Any hints on what to consider when deciding to change the engine? I recently bought a 30' custom made 1954 cruiser which originally had an inboard but was changed for a 15HP Mariner Outboard. I am thinking on changing back to a diesel inboard but first thought on inquiring of past experiences. The boat weighs over 5 tons and we only do coastal cruising (at sea).

TomRobb
09-07-2000, 01:41 PM
Yanmar diesel comes to mind. No doubt there are many others. If Dan the Runabout Man has a suggestion, I'd listen to it.

TomRobb
09-07-2000, 01:41 PM
Yanmar diesel comes to mind. No doubt there are many others. If Dan the Runabout Man has a suggestion, I'd listen to it.

TomRobb
09-07-2000, 01:41 PM
Yanmar diesel comes to mind. No doubt there are many others. If Dan the Runabout Man has a suggestion, I'd listen to it.

noquiklos
09-09-2000, 03:33 AM
My 32', 7.34 tonne cruising sloop came with a 30HP Atomic 4, which immediately became a passable mooring anchor. Before the start of the rebuild, we used a 10' Zodiac, with an 8hp outboard as a yawlboat, and she was much easier to control, when no wind, or extremely tight quarters made sailing into the slip impractical. (Think directional thrust, forward and reverse) It also would push her at 5 knots in a calm.
Now, for a little history.
In the days of large, heavy engines, a good rule of thumb (I've read) was 1hp per tonne. On modern boats, it seems 1hp per foot, regardless of displacement, is the prevailing rule of thumb.
Knowing the conditions in your cruising ground would help a lot to guesstimate your needs. Strong currents, river or tidal? Think higher hp. Do you find yourself motoring into strong headwinds often? Think big, again. Are you on a "schedule?" (Gotta be in the slip by 6, or I'll miss Happy Hour) Big motor.
On the other hand, do you like to sail, and only start the stinker to get in or out of the slip? 10hp Yanmars are light, efficient and reliable, (I've been told)and would fill those needs admirably.
Of course, no matter what you decide you need, (and bigger becomes geometrically more expensive) you'll need the right prop, and that's like, y'know, magic, and stuff.
All these opinions come, of course, from an engineless sailor, so a grain of salt is recommended.
Good luck.
Roy

noquiklos
09-09-2000, 03:33 AM
My 32', 7.34 tonne cruising sloop came with a 30HP Atomic 4, which immediately became a passable mooring anchor. Before the start of the rebuild, we used a 10' Zodiac, with an 8hp outboard as a yawlboat, and she was much easier to control, when no wind, or extremely tight quarters made sailing into the slip impractical. (Think directional thrust, forward and reverse) It also would push her at 5 knots in a calm.
Now, for a little history.
In the days of large, heavy engines, a good rule of thumb (I've read) was 1hp per tonne. On modern boats, it seems 1hp per foot, regardless of displacement, is the prevailing rule of thumb.
Knowing the conditions in your cruising ground would help a lot to guesstimate your needs. Strong currents, river or tidal? Think higher hp. Do you find yourself motoring into strong headwinds often? Think big, again. Are you on a "schedule?" (Gotta be in the slip by 6, or I'll miss Happy Hour) Big motor.
On the other hand, do you like to sail, and only start the stinker to get in or out of the slip? 10hp Yanmars are light, efficient and reliable, (I've been told)and would fill those needs admirably.
Of course, no matter what you decide you need, (and bigger becomes geometrically more expensive) you'll need the right prop, and that's like, y'know, magic, and stuff.
All these opinions come, of course, from an engineless sailor, so a grain of salt is recommended.
Good luck.
Roy

noquiklos
09-09-2000, 03:33 AM
My 32', 7.34 tonne cruising sloop came with a 30HP Atomic 4, which immediately became a passable mooring anchor. Before the start of the rebuild, we used a 10' Zodiac, with an 8hp outboard as a yawlboat, and she was much easier to control, when no wind, or extremely tight quarters made sailing into the slip impractical. (Think directional thrust, forward and reverse) It also would push her at 5 knots in a calm.
Now, for a little history.
In the days of large, heavy engines, a good rule of thumb (I've read) was 1hp per tonne. On modern boats, it seems 1hp per foot, regardless of displacement, is the prevailing rule of thumb.
Knowing the conditions in your cruising ground would help a lot to guesstimate your needs. Strong currents, river or tidal? Think higher hp. Do you find yourself motoring into strong headwinds often? Think big, again. Are you on a "schedule?" (Gotta be in the slip by 6, or I'll miss Happy Hour) Big motor.
On the other hand, do you like to sail, and only start the stinker to get in or out of the slip? 10hp Yanmars are light, efficient and reliable, (I've been told)and would fill those needs admirably.
Of course, no matter what you decide you need, (and bigger becomes geometrically more expensive) you'll need the right prop, and that's like, y'know, magic, and stuff.
All these opinions come, of course, from an engineless sailor, so a grain of salt is recommended.
Good luck.
Roy

Carlos
09-09-2000, 10:56 AM
Many thanks to TomRobb and noquiklos for their advise.
Just to let you know, my sailing is done at sea off the Callao port in Lima, PERU, where winds are mostly from the south at max 16 knots and no real heavy currents. My use of the engine is mainly for in/out of port, but sometimes will need it to get down south faster (avoid tacking).

Carlos
09-09-2000, 10:56 AM
Many thanks to TomRobb and noquiklos for their advise.
Just to let you know, my sailing is done at sea off the Callao port in Lima, PERU, where winds are mostly from the south at max 16 knots and no real heavy currents. My use of the engine is mainly for in/out of port, but sometimes will need it to get down south faster (avoid tacking).

Carlos
09-09-2000, 10:56 AM
Many thanks to TomRobb and noquiklos for their advise.
Just to let you know, my sailing is done at sea off the Callao port in Lima, PERU, where winds are mostly from the south at max 16 knots and no real heavy currents. My use of the engine is mainly for in/out of port, but sometimes will need it to get down south faster (avoid tacking).

Mike Hofgren
09-09-2000, 10:14 PM
I serviced/sold/area marketed & managed diesel (auto/industrial/marine) sales a while Carlos, . . and, doublessly you have info on new products availabilty; esp. with backup in Peru.

I thought 'what would I put if I wanted to get that job done reliably, at lowest cost?'

Here's what I'd do Carlos, need a common engine there are lots of, that you could get a good rebuilt example of. In that horsepower size (diesel) . . a Volkswagen Golf engine (for up to 30-35 hp, . . if the price is right, it'll do 15 hp in a heartbeat, and run forever) . . from what I understand, a good engine when applied right.

Then, you need conversion for marine application:
1. Heat exchanger system
2. Raw Water Pump
3. Reversing gear
4. Instruments

A heat exchanger could be a package, designed for the VW or sold by a reputable heat exchanger firm (not done this for a couple decades, so Thomas Register will tell who's doing that now), and this would be a good item to see if there's an effective source in Peru, (maybe there isn't) - they should reccomend a raw water pump . . could be one off an existing marine engine in the same (or even larger) size range. Need anti-corrosion cathodes in the raw water side. Heat exchangers are likely made in Peru. I think.

With this piped and sound, need a reversing gear. You could spend a lot of money, maybe not, if not, - DO buy a reverse gear adaptable to the VW engine. If not, don't worry. You've got lots of space in a vessel that size, so you can mount separately with a short jack shaft a suitable reversing gear. Where I'd look for the heat exchanger, raw water pump and reverse gear, is another conversion package that may be disused or recuperable, - like used on the zillions of American car V-8 marine engine conversions everywhere.

Now, the ideal is with an engine like that you'd get the horsepower you need at somewhere 2,500 - 3,000 RPM, get a deep reduction gear, (here's the sales engineer saying) "at least 3:1 (3 to 1)". So you have about 800 - 1000 prop RPM. Will really maneuver well. Don't loose sleep Carlos, if you can arrive at a 2:1, a 1-1/2 to 1, even direct drive . . if you get the right best prop, it'll do the job, just don't expect to stop on a dime.

Intruments: esp. engine lube oil pressure, engine temp, a Tachometer (saves time and expense on the engine), -- and you're in business, Carlos!

(you don't need a torsional analysis of the driveline Carlos, but if it's a tug boat - different matter)

iron Mike http://media4.hypernet.com/~dick/ubb/smile.gif

[This message has been edited by Mike Hofgren (edited 09-09-2000).]

Mike Hofgren
09-09-2000, 10:14 PM
I serviced/sold/area marketed & managed diesel (auto/industrial/marine) sales a while Carlos, . . and, doublessly you have info on new products availabilty; esp. with backup in Peru.

I thought 'what would I put if I wanted to get that job done reliably, at lowest cost?'

Here's what I'd do Carlos, need a common engine there are lots of, that you could get a good rebuilt example of. In that horsepower size (diesel) . . a Volkswagen Golf engine (for up to 30-35 hp, . . if the price is right, it'll do 15 hp in a heartbeat, and run forever) . . from what I understand, a good engine when applied right.

Then, you need conversion for marine application:
1. Heat exchanger system
2. Raw Water Pump
3. Reversing gear
4. Instruments

A heat exchanger could be a package, designed for the VW or sold by a reputable heat exchanger firm (not done this for a couple decades, so Thomas Register will tell who's doing that now), and this would be a good item to see if there's an effective source in Peru, (maybe there isn't) - they should reccomend a raw water pump . . could be one off an existing marine engine in the same (or even larger) size range. Need anti-corrosion cathodes in the raw water side. Heat exchangers are likely made in Peru. I think.

With this piped and sound, need a reversing gear. You could spend a lot of money, maybe not, if not, - DO buy a reverse gear adaptable to the VW engine. If not, don't worry. You've got lots of space in a vessel that size, so you can mount separately with a short jack shaft a suitable reversing gear. Where I'd look for the heat exchanger, raw water pump and reverse gear, is another conversion package that may be disused or recuperable, - like used on the zillions of American car V-8 marine engine conversions everywhere.

Now, the ideal is with an engine like that you'd get the horsepower you need at somewhere 2,500 - 3,000 RPM, get a deep reduction gear, (here's the sales engineer saying) "at least 3:1 (3 to 1)". So you have about 800 - 1000 prop RPM. Will really maneuver well. Don't loose sleep Carlos, if you can arrive at a 2:1, a 1-1/2 to 1, even direct drive . . if you get the right best prop, it'll do the job, just don't expect to stop on a dime.

Intruments: esp. engine lube oil pressure, engine temp, a Tachometer (saves time and expense on the engine), -- and you're in business, Carlos!

(you don't need a torsional analysis of the driveline Carlos, but if it's a tug boat - different matter)

iron Mike http://media4.hypernet.com/~dick/ubb/smile.gif

[This message has been edited by Mike Hofgren (edited 09-09-2000).]

Mike Hofgren
09-09-2000, 10:14 PM
I serviced/sold/area marketed & managed diesel (auto/industrial/marine) sales a while Carlos, . . and, doublessly you have info on new products availabilty; esp. with backup in Peru.

I thought 'what would I put if I wanted to get that job done reliably, at lowest cost?'

Here's what I'd do Carlos, need a common engine there are lots of, that you could get a good rebuilt example of. In that horsepower size (diesel) . . a Volkswagen Golf engine (for up to 30-35 hp, . . if the price is right, it'll do 15 hp in a heartbeat, and run forever) . . from what I understand, a good engine when applied right.

Then, you need conversion for marine application:
1. Heat exchanger system
2. Raw Water Pump
3. Reversing gear
4. Instruments

A heat exchanger could be a package, designed for the VW or sold by a reputable heat exchanger firm (not done this for a couple decades, so Thomas Register will tell who's doing that now), and this would be a good item to see if there's an effective source in Peru, (maybe there isn't) - they should reccomend a raw water pump . . could be one off an existing marine engine in the same (or even larger) size range. Need anti-corrosion cathodes in the raw water side. Heat exchangers are likely made in Peru. I think.

With this piped and sound, need a reversing gear. You could spend a lot of money, maybe not, if not, - DO buy a reverse gear adaptable to the VW engine. If not, don't worry. You've got lots of space in a vessel that size, so you can mount separately with a short jack shaft a suitable reversing gear. Where I'd look for the heat exchanger, raw water pump and reverse gear, is another conversion package that may be disused or recuperable, - like used on the zillions of American car V-8 marine engine conversions everywhere.

Now, the ideal is with an engine like that you'd get the horsepower you need at somewhere 2,500 - 3,000 RPM, get a deep reduction gear, (here's the sales engineer saying) "at least 3:1 (3 to 1)". So you have about 800 - 1000 prop RPM. Will really maneuver well. Don't loose sleep Carlos, if you can arrive at a 2:1, a 1-1/2 to 1, even direct drive . . if you get the right best prop, it'll do the job, just don't expect to stop on a dime.

Intruments: esp. engine lube oil pressure, engine temp, a Tachometer (saves time and expense on the engine), -- and you're in business, Carlos!

(you don't need a torsional analysis of the driveline Carlos, but if it's a tug boat - different matter)

iron Mike http://media4.hypernet.com/~dick/ubb/smile.gif

[This message has been edited by Mike Hofgren (edited 09-09-2000).]