Converting air cooled to water cooled...maybe
 

I just joined this group and have a dilema to present:

My boat has a large engine room and I want to add a genset to it. BUT
it must be diesel as I dont want any gasoline aboard. I can buy a new
marine diesel gen set with warer cooling for $7,000 or so. I dont have
that kind of money to spend. But I can buy a new diesel, AIR COOLED,
getset for under $1000. With the gen set in the engine room I will
either have to supply a MINIMUM (probably more) of 1000 CFM of cool air
and exhaust it as well. This is not altogether too dificult, BUT that
air I am supplying will be SALT air and will promote corrosion in the
new gen set, I am sure.

So I am wondering about the possibility of converting the air cooled
diesel to a water cooled diesel with a salt to fresh water heat
exchanger. I read somewhere once that someone did this by coiling
copper pipe around the head of the engine for the fresh water part and
used a wet exhaust to cool the exhaust. But with no details of how the
fresh water cooling was actually constructed on the engine, and my
limited imagination in this area, I dont see how it could work. I
think it would take more than cooling the head alone.

Does anyone have any ideas along these lines??

Converting air cooled to water cooled...maybe
 

jim.isbell wrote:
I just joined this group and have a dilema to present:

My boat has a large engine room and I want to add a genset to it. BUT
it must be diesel as I dont want any gasoline aboard. I can buy a new
marine diesel gen set with warer cooling for $7,000 or so. I dont have
that kind of money to spend. But I can buy a new diesel, AIR COOLED,
getset for under $1000. With the gen set in the engine room I will
either have to supply a MINIMUM (probably more) of 1000 CFM of cool air
and exhaust it as well. This is not altogether too dificult, BUT that
air I am supplying will be SALT air and will promote corrosion in the
new gen set, I am sure.

So I am wondering about the possibility of converting the air cooled
diesel to a water cooled diesel with a salt to fresh water heat
exchanger. I read somewhere once that someone did this by coiling
copper pipe around the head of the engine for the fresh water part and
used a wet exhaust to cool the exhaust. But with no details of how the
fresh water cooling was actually constructed on the engine, and my
limited imagination in this area, I dont see how it could work. I
think it would take more than cooling the head alone.

Does anyone have any ideas along these lines??

I wouldn't waste my time on this, it's not worth it, your just looking
for trouble and the gen set will not be CG approved. If you have a
problem, fire, CO gas, ect, your in trouble, your insurance won't cover
it. And the boat will never pass a survey.

Converting air cooled to water cooled...maybe
 

On 27 Jul 2006 09:20:50 -0700, "Capt John"
wrote:

I wouldn't waste my time on this, it's not worth it, your just looking
for trouble and the gen set will not be CG approved. If you have a
problem, fire, CO gas, ect, your in trouble, your insurance won't cover
it. And the boat will never pass a survey.

I agree. Probably your best bet is to find a good used "takeout".
Check with one of your local Kohler or Onan dealers, they may have
some laying around. Also check on EBAY.

Converting air cooled to water cooled...maybe
 

You don't want gasoline because it is too dangerous....and you want to jury
rig cooling of a stay ashore generator???? Must be a troll.
"jim.isbell" wrote in message
oups.com...
I just joined this group and have a dilema to present:

My boat has a large engine room and I want to add a genset to it. BUT
it must be diesel as I dont want any gasoline aboard. I can buy a new
marine diesel gen set with warer cooling for $7,000 or so. I dont have
that kind of money to spend. But I can buy a new diesel, AIR COOLED,
getset for under $1000. With the gen set in the engine room I will
either have to supply a MINIMUM (probably more) of 1000 CFM of cool air
and exhaust it as well. This is not altogether too dificult, BUT that
air I am supplying will be SALT air and will promote corrosion in the
new gen set, I am sure.

So I am wondering about the possibility of converting the air cooled
diesel to a water cooled diesel with a salt to fresh water heat
exchanger. I read somewhere once that someone did this by coiling
copper pipe around the head of the engine for the fresh water part and
used a wet exhaust to cool the exhaust. But with no details of how the
fresh water cooling was actually constructed on the engine, and my
limited imagination in this area, I dont see how it could work. I
think it would take more than cooling the head alone.

Does anyone have any ideas along these lines??

Converting air cooled to water cooled...maybe
 

No, not a troll. And NO, I dont want to "jurry rig."

I want to do it right the first time. I see no reason why ducting air
to an air cooled device is jurry rigging. After all we duct sea water
to a fresh water cooled engine to cool the fresh water and we dont call
that "jurry rigged". If any thing is a Rube Goldperg design, fresh
water cooled engines are!!!

Sure, if one does not prepare for all the challanges, it would be jurry
rigged. With propper sensing on engines we prevent destructive
failures. Why cant we assume the same for an air cooled system? I
would use temperature sensing to make sure there was no fire hazard
etc.

Dave W wrote:
You don't want gasoline because it is too dangerous....and you want to jury
rig cooling of a stay ashore generator???? Must be a troll.
"jim.isbell" wrote in message
oups.com...
I just joined this group and have a dilema to present:

My boat has a large engine room and I want to add a genset to it. BUT
it must be diesel as I dont want any gasoline aboard. I can buy a new
marine diesel gen set with warer cooling for $7,000 or so. I dont have
that kind of money to spend. But I can buy a new diesel, AIR COOLED,
getset for under $1000. With the gen set in the engine room I will
either have to supply a MINIMUM (probably more) of 1000 CFM of cool air
and exhaust it as well. This is not altogether too dificult, BUT that
air I am supplying will be SALT air and will promote corrosion in the
new gen set, I am sure.

So I am wondering about the possibility of converting the air cooled
diesel to a water cooled diesel with a salt to fresh water heat
exchanger. I read somewhere once that someone did this by coiling
copper pipe around the head of the engine for the fresh water part and
used a wet exhaust to cool the exhaust. But with no details of how the
fresh water cooling was actually constructed on the engine, and my
limited imagination in this area, I dont see how it could work. I
think it would take more than cooling the head alone.

Does anyone have any ideas along these lines??

Converting air cooled to water cooled...maybe
 

Jim,

Sorry, but changing the mode of cooling for an engine without proper
engineering *is* jury rigging. Not at all the same as just using a
water-to-water heat exchanger. If you're worried about "salt" air, and
you're running in cold water, put a de-mister coil in the air duct and
pipe sea water through it chill it and pull the moisture out of the air.
Now that's a Rube'd device that would actually work. Bear in mind
though that by the time you buy all the required equipment to make the
aircooled unit functional and long-lived, you'll have a bunch more into
it than the $1K, and you'll have a less fuel-efficient unit.

Keith Hughes

jim.isbell wrote:
No, not a troll. And NO, I dont want to "jurry rig."

I want to do it right the first time. I see no reason why ducting air
to an air cooled device is jurry rigging. After all we duct sea water
to a fresh water cooled engine to cool the fresh water and we dont call
that "jurry rigged". If any thing is a Rube Goldperg design, fresh
water cooled engines are!!!

Sure, if one does not prepare for all the challanges, it would be jurry
rigged. With propper sensing on engines we prevent destructive
failures. Why cant we assume the same for an air cooled system? I
would use temperature sensing to make sure there was no fire hazard
etc.

Dave W wrote:

You don't want gasoline because it is too dangerous....and you want to jury
rig cooling of a stay ashore generator???? Must be a troll.
"jim.isbell" wrote in message
groups.com...

I just joined this group and have a dilema to present:

My boat has a large engine room and I want to add a genset to it. BUT
it must be diesel as I dont want any gasoline aboard. I can buy a new
marine diesel gen set with warer cooling for $7,000 or so. I dont have
that kind of money to spend. But I can buy a new diesel, AIR COOLED,
getset for under $1000. With the gen set in the engine room I will
either have to supply a MINIMUM (probably more) of 1000 CFM of cool air
and exhaust it as well. This is not altogether too dificult, BUT that
air I am supplying will be SALT air and will promote corrosion in the
new gen set, I am sure.

So I am wondering about the possibility of converting the air cooled
diesel to a water cooled diesel with a salt to fresh water heat
exchanger. I read somewhere once that someone did this by coiling
copper pipe around the head of the engine for the fresh water part and
used a wet exhaust to cool the exhaust. But with no details of how the
fresh water cooling was actually constructed on the engine, and my
limited imagination in this area, I dont see how it could work. I
think it would take more than cooling the head alone.

Does anyone have any ideas along these lines??

Converting air cooled to water cooled...maybe
 

"jim.isbell" wrote in message
ups.com...
No, not a troll. And NO, I dont want to "jurry rig."

No, but you want to "warer cool".

Judge not, lest ye be judged.
Sounds like a troll to me.

Converting air cooled to water cooled...maybe
 

You could try this. A fan sucking from a long duct inside the hull.
If the hull is steel or aluminum, it would be quite effectively cooled
air from the sea water. The duct plays over the cylinder then exhaust
manifold.

Brian Whatcott.


On 28 Jul 2006 07:43:15 -0700, "jim.isbell"
wrote:

No, not a troll. And NO, I dont want to "jurry rig."

I want to do it right the first time. I see no reason why ducting air
to an air cooled device is jurry rigging. After all we duct sea water
to a fresh water cooled engine to cool the fresh water and we dont call
that "jurry rigged". If any thing is a Rube Goldperg design, fresh
water cooled engines are!!!

Sure, if one does not prepare for all the challanges, it would be jurry
rigged. With propper sensing on engines we prevent destructive
failures. Why cant we assume the same for an air cooled system? I
would use temperature sensing to make sure there was no fire hazard
etc.

Dave W wrote:
You don't want gasoline because it is too dangerous....and you want to jury
rig cooling of a stay ashore generator???? Must be a troll.
"jim.isbell" wrote in message
oups.com...
I just joined this group and have a dilema to present:

My boat has a large engine room and I want to add a genset to it. BUT
it must be diesel as I dont want any gasoline aboard. I can buy a new
marine diesel gen set with warer cooling for $7,000 or so. I dont have
that kind of money to spend. But I can buy a new diesel, AIR COOLED,
getset for under $1000. With the gen set in the engine room I will
either have to supply a MINIMUM (probably more) of 1000 CFM of cool air
and exhaust it as well. This is not altogether too dificult, BUT that
air I am supplying will be SALT air and will promote corrosion in the
new gen set, I am sure.

So I am wondering about the possibility of converting the air cooled
diesel to a water cooled diesel with a salt to fresh water heat
exchanger. I read somewhere once that someone did this by coiling
copper pipe around the head of the engine for the fresh water part and
used a wet exhaust to cool the exhaust. But with no details of how the
fresh water cooling was actually constructed on the engine, and my
limited imagination in this area, I dont see how it could work. I
think it would take more than cooling the head alone.

Does anyone have any ideas along these lines??

Converting air cooled to water cooled...maybe
 

Keith Hughes wrote:
Jim,

Sorry, but changing the mode of cooling for an engine without proper
engineering *is* jury rigging.

I didnt say I wanted to do it "without proper engineering."

That is why I am here, to get information on how to properly engineer
it. I am an engineer so with proper input I think this can be done.

As you say, it may not be economical, but to reject it out of hand is
shortsighted.

I always like to point out to young engineers that if we didnt try what
couldnt be done, nothing would ever be accomplished. Almost any
engineering project has never been done before or it wouldnt be in the
engineering department, the technicians in the lab would have looked it
up and done it by now.

Converting air cooled to water cooled...maybe
 

jim.isbell wrote:
Keith Hughes wrote:

Jim,

Sorry, but changing the mode of cooling for an engine without proper
engineering *is* jury rigging.


I didnt say I wanted to do it "without proper engineering."

OK, but 'wrapping copper tubing around the cylinders' doesn't sound like
an approach resulting from much engineering analysis.

That is why I am here, to get information on how to properly engineer
it. I am an engineer so with proper input I think this can be done.

Well then, surely you must know that you first need the designed
combustion chamber temperature range and the thermal conduction profile
for the cylinder sleeve (top to bottom), to properly size the multiple,
vertically segmented, cooling loops you'll require. You could estimate
the vertical temperature cline by analyzing the relative fin surface
areas, air flow rates, and standard thermal conduction value (F sub r, U
sub L as ASHRAE defines it) and the emissivity of the fin material. And
that just gets you the info you need to design the heat exchange
process. You need to go through the same exercise with the copper
tubing with the bonding method, heat transfer characteristics, mass flow
requirements, baffling to ensure turbulent flow, etc., etc. Not a
trivial exercise.


As you say, it may not be economical, but to reject it out of hand is
shortsighted.

As you seem to have rejected, out of hand as you say, the most simple
way of achieving your stated goal? I.e., not air cooling with "salt"
air. Properly trapped (i.e. collection drain) demisters are the
standard method for achieving these results. Used all the time to pull
moisture from ductwork.

I always like to point out to young engineers that if we didnt try what
couldnt be done, nothing would ever be accomplished.

You might also want to point out that trying to create novel designs and
implementations when existing designs *meet all customer requirements*
results in nothing but higher development costs and, typically,
unnecessary process complexity. This, IME, is the biggest failing of
most engineers (excepting R&D of course).

And, I might point out, this thread epitomizes that situation; trying to
redesign the end point of the process (i.e. the engine) instead of
addressing the problem earlier in the process (i.e. the cooling air
supply) where it can be solved easier, cheaper, and with less complexity.

Almost any
engineering project has never been done before or it wouldnt be in the
engineering department, the technicians in the lab would have looked it
up and done it by now.

Well, sorry but that's just ridiculous. Virtually all day to day
engineering projects are varying implementations of basic
systems/processes that are done all the time. The vast majority of
engineers are not involved in R&D work; they're doing practical process
applications using basic engineering principles. I'm not trivializing
the Engineering process. The most difficult engineering exercise, IME,
is taking an existing process or piece of equipment and implementing
that process or equipment into a specific/unique application and
achieving a result that is timely rugged, efficient, cost-effective, and
meets the specific needs of the end user. If you can do all of those
five, you're a damn fine engineer.

Keith Hughes

Converting air cooled to water cooled...maybe
 

This has degenerated from a discussion of possibilities into what I
would expect in a board meeting, not in an engineering lab. So I am
bailing out to look elsewhere.

By the way, I didnt reject air cooling, only expressed my concern that
it could cause corosion. BTW, thanks for those comments, they WERE
valuable.

Keith Hughes wrote:
jim.isbell wrote:
Keith Hughes wrote:

Jim,

Sorry, but changing the mode of cooling for an engine without proper
engineering *is* jury rigging.


I didnt say I wanted to do it "without proper engineering."

OK, but 'wrapping copper tubing around the cylinders' doesn't sound like
an approach resulting from much engineering analysis.

That is why I am here, to get information on how to properly engineer
it. I am an engineer so with proper input I think this can be done.

Well then, surely you must know that you first need the designed
combustion chamber temperature range and the thermal conduction profile
for the cylinder sleeve (top to bottom), to properly size the multiple,
vertically segmented, cooling loops you'll require. You could estimate
the vertical temperature cline by analyzing the relative fin surface
areas, air flow rates, and standard thermal conduction value (F sub r, U
sub L as ASHRAE defines it) and the emissivity of the fin material. And
that just gets you the info you need to design the heat exchange
process. You need to go through the same exercise with the copper
tubing with the bonding method, heat transfer characteristics, mass flow
requirements, baffling to ensure turbulent flow, etc., etc. Not a
trivial exercise.


As you say, it may not be economical, but to reject it out of hand is
shortsighted.

As you seem to have rejected, out of hand as you say, the most simple
way of achieving your stated goal? I.e., not air cooling with "salt"
air. Properly trapped (i.e. collection drain) demisters are the
standard method for achieving these results. Used all the time to pull
moisture from ductwork.

I always like to point out to young engineers that if we didnt try what
couldnt be done, nothing would ever be accomplished.

You might also want to point out that trying to create novel designs and
implementations when existing designs *meet all customer requirements*
results in nothing but higher development costs and, typically,
unnecessary process complexity. This, IME, is the biggest failing of
most engineers (excepting R&D of course).

And, I might point out, this thread epitomizes that situation; trying to
redesign the end point of the process (i.e. the engine) instead of
addressing the problem earlier in the process (i.e. the cooling air
supply) where it can be solved easier, cheaper, and with less complexity.

Almost any
engineering project has never been done before or it wouldnt be in the
engineering department, the technicians in the lab would have looked it
up and done it by now.

Well, sorry but that's just ridiculous. Virtually all day to day
engineering projects are varying implementations of basic
systems/processes that are done all the time. The vast majority of
engineers are not involved in R&D work; they're doing practical process
applications using basic engineering principles. I'm not trivializing
the Engineering process. The most difficult engineering exercise, IME,
is taking an existing process or piece of equipment and implementing
that process or equipment into a specific/unique application and
achieving a result that is timely rugged, efficient, cost-effective, and
meets the specific needs of the end user. If you can do all of those
five, you're a damn fine engineer.

Keith Hughes

Converting air cooled to water cooled...maybe
 

On Sat, 29 Jul 2006 09:20:49 -0700, Keith Hughes
wrote:

That is why I am here, to get information on how to properly engineer
it. I am an engineer so with proper input I think this can be done.

Well then, surely you must know that you first need the designed
combustion chamber temperature range and the thermal conduction profile
for the cylinder sleeve (top to bottom), to properly size the multiple,
vertically segmented, cooling loops you'll require. You could estimate
the vertical temperature cline by analyzing the relative fin surface
areas, air flow rates, and standard thermal conduction value (F sub r, U
sub L as ASHRAE defines it) and the emissivity of the fin material. And
that just gets you the info you need to design the heat exchange
process. You need to go through the same exercise with the copper
tubing with the bonding method, heat transfer characteristics, mass flow
requirements, baffling to ensure turbulent flow, etc., etc. Not a
trivial exercise.

You could always just measure the temp of the head and block in
different locations and under different loads. Knowing the difference
in block temp at idle and full load would be very useful.

Using a thermocouple(s) to measure the block temp between the fins
would be a good start. It may be the fins are designed to give a
fairly even temp throughout the block itself.

Some slightly oversized copper tube that's squashed to give an
interference fit between the fins should give good conduction, if not
enough then use more than one layer.

In testing the thermocouple could be used to monitor the block temp
under water cooling, to ensure it's within the same values as for air
cooling.

One issue with copper is that it may fracture through vibration if not
supported properly, so stainless may be better for some parts.

A tank, manifold, thermostat, pressure relief, and raw water heat
exchanger would also be needed. Also a thermal cutout if the cooling
fails. Different temps at top and bottom of block could be accomodated
by different thermostats.

Doing some practice on an old engine might give some useful lessons.

cheers,
Pete.

Converting air cooled to water cooled...maybe
 

"Brian Whatcott" wrote in message
...
You could try this. A fan sucking from a long duct inside the hull.
If the hull is steel or aluminum, it would be quite effectively cooled
air from the sea water. The duct plays over the cylinder then exhaust
manifold.

Brian Whatcott.



I have actually done this with excellent results.

Basically, I contained the diesel generator in a soundproofed box and sucked
air out of the box. The air inlet sucked air that was first passed over a
large area of the steel hull. The incoming air being specifically directed
at the cylinder head area.

As a finishing touch I installed a fire detector and two heat sensors both
of which can independently cut the engine and fuel in the event of the
compartment overheating.

Hope this helps.

Adrian Smith.

Converting air cooled to water cooled...maybe
 

"jim.isbell" wrote in message
oups.com...
This has degenerated from a discussion of possibilities into what I
would expect in a board meeting, not in an engineering lab. So I am
bailing out to look elsewhere.

By the way, I didnt reject air cooling, only expressed my concern that
it could cause corosion. BTW, thanks for those comments, they WERE
valuable.


Don't bail out too soon, there will always be more 'you can't do that' types
than 'that sounds interesting, let's have a think around the problem' types.

Adrian Smith.

Converting air cooled to water cooled...maybe
 

Adrian Smith wrote:

Don't bail out too soon, there will always be more 'you can't do that' types
than 'that sounds interesting, let's have a think around the problem' types.

Adrian Smith.

I will continue to look at the problem, not bailing out yet.

I dont have a metal hull anymore. My current boat is Fiberglass. The
last one was steel but I sold it.

However, my research seems to indicate that I need about 1500 cfm and
that shouldnt be too hard to get.

Converting air cooled to water cooled...maybe
 

"jim.isbell" wrote in message
ups.com...
Adrian Smith wrote:

Don't bail out too soon, there will always be more 'you can't do that'
types
than 'that sounds interesting, let's have a think around the problem'
types.

Adrian Smith.

I will continue to look at the problem, not bailing out yet.

I dont have a metal hull anymore. My current boat is Fiberglass. The
last one was steel but I sold it.

However, my research seems to indicate that I need about 1500 cfm and
that shouldnt be too hard to get.


How did you arrive at 1500cfm? (Asking cause I just guessed.)

I used an oversized fan, linked to a temperature controlled speed
controller, with auto shut down should things get too hot.

Even at full tilt, 3 KW, the cooling fan never reaches anywhere near full
speed.

Adrian Smith