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#21
posted to rec.boats.building
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Air cooled two stroke as inboard?
On Mon, 24 Aug 2009 12:08:53 +0000, Richard Casady wrote:
On Fri, 21 Aug 2009 21:11:56 GMT, "Tim W" wrote: Isn't an old Vetus an air cooled two stroke marine engine, or am I imagining some of that? And didn't they do something strange like run backwards and forwards? Not strange. Steam is nearly dead, for large merchant ships, replaced by direct drive Diesel. You stop and reset the valve gear, and then restart turning the other direction. If you are inept at manuvering, you can run out of the compressed air used to start the engine. Vintage Washington, Atlas and Enterprise (and others) diesel engines did this also. They were frequently used in tugs and other medium sized boats. Not sure if there are any modern midsize diesels which work this way. |
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#22
posted to rec.boats.building
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Air cooled two stroke as inboard?
In article d07591e1-4de8-4e4a-9dca-
, says... I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin Two strokes want to run at one speed... It would be very inefficient in that situation. Not to mention, unless it was a race boat, the sound would probably draw gunfire on the local lakes  -- Wafa free since 2009 |
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#24
posted to rec.boats.building
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Air cooled two stroke as inboard?
In article ,
says... On Sat, 22 Aug 2009 10:36:47 -0400, wrote: On Sat, 22 Aug 2009 09:32:43 -0400, "mmc" wrote: "Andrew Erickson" wrote in message ... In article , wrote: On Fri, 21 Aug 2009 11:16:09 -0400, Andrew Erickson wrote: In article , wrote: On Thu, 20 Aug 2009 20:21:25 -0700 (PDT), Robin wrote: I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin How are you going to cool it adequately? I would assume, for an air-cooled engine, that's where the "adequate air circulation" comes in to play. One would probably have to be a bit careful not to push the engine too hard too long, as well, since many applications for these engines are not at steady high output. (There are exceptions--ultralight aircraft engines for one example.) I don't see any inherent insurmountable objections to doing this. A speed reduction of some sort would be nearly essential, of course, or else using a jet drive. Small two stroke engines in general tend to be inefficient and noisy and smelly and a bit temperamental, although the newer ones are vastly improved over older designs. On the other hand, they are lightweight and generally unaffected by being off level (limited mostly by the particular carburetor design), which can be advantages for use in a small boat. It's not as though there aren't a great many jet skis and boats with older outboards zipping around just fine with two stroke engines every day. Granted, most of these are water cooled, but still... There is a world of difference between a water cooled two-stroke, and an aircooled two-stroke, especially in a confined space. When I ask about cooling, it's because there will be a need for BIG fans to make this work. Air cooled motorcycles tend to overheat sitting in traffic. They need to keep moving to maintain reasonable temps. "Police Special" Harleys have a detuned and lower compression engine for this reason. Just being outside in open air is not enough. Put an engine like that as an inboard on a boat and you are in for trouble. It really needs to be addressed. I'm not sure it can be done practically. Snowmobile engines traditionally were air cooled two stroke engines (although more recently four stroke engines and liquid cooling have become common), and generally inside cowlings, and they generally manage to avoid overheating just fine. Likewise, chainsaw engines don't tend to overheat all the time, despite often being run rather hard. It's a question of the specific engine design (presumably based on the intended application), not a problem common to all two strokes. You are quite correct, though, that the original poster (should they attempt the conversion) should give some careful consideration to cooling. I don't think the end result would ever be an ideal boat motor, but I also think it could be perfectly adequate and probably a lot of fun if you're into that sort of thing. -- Andrew Erickson "He is no fool who gives what he cannot keep to gain that which he cannot lose." -- Jim Elliot Some small outboards were/are air cooled as well like the Sears Game Fishers, I think up to 5hp. Not even remotely the same thing as mounting an air cooled engine as an inboard. Err - the Honda 2 H.P. is an air cooled engine. Apparently has no problems with its cooling system. I had, and several friends presently have, air cooled 2-stroke, portable generators. Millions of lawn mowers are air cooled. I could go on but why bother. the O.P. already mentioned that he could foresee the problem of adequate air supply. What in the world is going to be a problem? Cheers, Bruce (bruceinbangkokatgmaildotcom) Man, if I were ever camped next to someone with a 2 smoke genset, they better also have a good supply of ammunition -- Wafa free since 2009 |
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#25
posted to rec.boats.building
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Air cooled two stroke as inboard?
In article ,
says... On Sat, 22 Aug 2009 09:32:43 -0400, "mmc" wrote: "Andrew Erickson" wrote in message ... In article , wrote: On Fri, 21 Aug 2009 11:16:09 -0400, Andrew Erickson wrote: In article , wrote: On Thu, 20 Aug 2009 20:21:25 -0700 (PDT), Robin wrote: I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin How are you going to cool it adequately? I would assume, for an air-cooled engine, that's where the "adequate air circulation" comes in to play. One would probably have to be a bit careful not to push the engine too hard too long, as well, since many applications for these engines are not at steady high output. (There are exceptions--ultralight aircraft engines for one example.) I don't see any inherent insurmountable objections to doing this. A speed reduction of some sort would be nearly essential, of course, or else using a jet drive. Small two stroke engines in general tend to be inefficient and noisy and smelly and a bit temperamental, although the newer ones are vastly improved over older designs. On the other hand, they are lightweight and generally unaffected by being off level (limited mostly by the particular carburetor design), which can be advantages for use in a small boat. It's not as though there aren't a great many jet skis and boats with older outboards zipping around just fine with two stroke engines every day. Granted, most of these are water cooled, but still... There is a world of difference between a water cooled two-stroke, and an aircooled two-stroke, especially in a confined space. When I ask about cooling, it's because there will be a need for BIG fans to make this work. Air cooled motorcycles tend to overheat sitting in traffic. They need to keep moving to maintain reasonable temps. "Police Special" Harleys have a detuned and lower compression engine for this reason. Just being outside in open air is not enough. Put an engine like that as an inboard on a boat and you are in for trouble. It really needs to be addressed. I'm not sure it can be done practically. Snowmobile engines traditionally were air cooled two stroke engines (although more recently four stroke engines and liquid cooling have become common), and generally inside cowlings, and they generally manage to avoid overheating just fine. Likewise, chainsaw engines don't tend to overheat all the time, despite often being run rather hard. It's a question of the specific engine design (presumably based on the intended application), not a problem common to all two strokes. You are quite correct, though, that the original poster (should they attempt the conversion) should give some careful consideration to cooling. I don't think the end result would ever be an ideal boat motor, but I also think it could be perfectly adequate and probably a lot of fun if you're into that sort of thing. -- Andrew Erickson "He is no fool who gives what he cannot keep to gain that which he cannot lose." -- Jim Elliot Some small outboards were/are air cooled as well like the Sears Game Fishers, I think up to 5hp. As well as the current Honda 2 H.P., which as far as I know has never had a problem with its cooling system. In fact Honda brags considerably about how well it works and how light it is. Given that literally millions of air cooled lawn mowers have operated successfully with little (probably no) maintenance all over the world it is doubtful that air cooling is going to be a problem. Cheers, Bruce (bruceinbangkokatgmaildotcom) I just don't remember ever seeing a two smoke lawnmower... Not doubting you, just started thinking about it and I was like... hummmmm, nope, just never saw one that I can remember.. -- Wafa free since 2009 |
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#26
posted to rec.boats.building
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Air cooled two stroke as inboard?
On Mon, 24 Aug 2009 12:01:01 -0400, JustWait
wrote: In article , says... On Sat, 22 Aug 2009 10:36:47 -0400, wrote: On Sat, 22 Aug 2009 09:32:43 -0400, "mmc" wrote: "Andrew Erickson" wrote in message ... In article , wrote: On Fri, 21 Aug 2009 11:16:09 -0400, Andrew Erickson wrote: In article , wrote: On Thu, 20 Aug 2009 20:21:25 -0700 (PDT), Robin wrote: I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin How are you going to cool it adequately? I would assume, for an air-cooled engine, that's where the "adequate air circulation" comes in to play. One would probably have to be a bit careful not to push the engine too hard too long, as well, since many applications for these engines are not at steady high output. (There are exceptions--ultralight aircraft engines for one example.) I don't see any inherent insurmountable objections to doing this. A speed reduction of some sort would be nearly essential, of course, or else using a jet drive. Small two stroke engines in general tend to be inefficient and noisy and smelly and a bit temperamental, although the newer ones are vastly improved over older designs. On the other hand, they are lightweight and generally unaffected by being off level (limited mostly by the particular carburetor design), which can be advantages for use in a small boat. It's not as though there aren't a great many jet skis and boats with older outboards zipping around just fine with two stroke engines every day. Granted, most of these are water cooled, but still... There is a world of difference between a water cooled two-stroke, and an aircooled two-stroke, especially in a confined space. When I ask about cooling, it's because there will be a need for BIG fans to make this work. Air cooled motorcycles tend to overheat sitting in traffic. They need to keep moving to maintain reasonable temps. "Police Special" Harleys have a detuned and lower compression engine for this reason. Just being outside in open air is not enough. Put an engine like that as an inboard on a boat and you are in for trouble. It really needs to be addressed. I'm not sure it can be done practically. Snowmobile engines traditionally were air cooled two stroke engines (although more recently four stroke engines and liquid cooling have become common), and generally inside cowlings, and they generally manage to avoid overheating just fine. Likewise, chainsaw engines don't tend to overheat all the time, despite often being run rather hard. It's a question of the specific engine design (presumably based on the intended application), not a problem common to all two strokes. You are quite correct, though, that the original poster (should they attempt the conversion) should give some careful consideration to cooling. I don't think the end result would ever be an ideal boat motor, but I also think it could be perfectly adequate and probably a lot of fun if you're into that sort of thing. -- Andrew Erickson "He is no fool who gives what he cannot keep to gain that which he cannot lose." -- Jim Elliot Some small outboards were/are air cooled as well like the Sears Game Fishers, I think up to 5hp. Not even remotely the same thing as mounting an air cooled engine as an inboard. Err - the Honda 2 H.P. is an air cooled engine. Apparently has no problems with its cooling system. I had, and several friends presently have, air cooled 2-stroke, portable generators. Millions of lawn mowers are air cooled. I could go on but why bother. the O.P. already mentioned that he could foresee the problem of adequate air supply. What in the world is going to be a problem? Cheers, Bruce (bruceinbangkokatgmaildotcom) Man, if I were ever camped next to someone with a 2 smoke genset, they better also have a good supply of ammunition Why? The little 1 KW (actually 900-something watts) 2 stroke units, made in India by the way, run as quite as a 4-stroke. Not all 2-strokes have tunes exhaust. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
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#27
posted to rec.boats.building
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Air cooled two stroke as inboard?
On Mon, 24 Aug 2009 11:41:40 -0400, JustWait
wrote: In article d07591e1-4de8-4e4a-9dca- , says... I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin Two strokes want to run at one speed... It would be very inefficient in that situation. Not to mention, unless it was a race boat, the sound would probably draw gunfire on the local lakes Err - like the Yamaha 250? The one that used to trounce 500 cc 4-strokes in the old days? Even with its tuned pipes it has usable over several thousand RPM. Actually it is the tuned exhaust that wants to run at one speed. The old 2-stroke motorcycles - Famous James, et al, were happy to run over a fairly broad range. (So is my 2-stroke outboard :-) Cheers, Bruce (bruceinbangkokatgmaildotcom) |
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#28
posted to rec.boats.building
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Air cooled two stroke as inboard?
Bruce In Bangkok wrote:
On Mon, 24 Aug 2009 12:01:01 -0400, JustWait wrote: In article , says... On Sat, 22 Aug 2009 10:36:47 -0400, wrote: On Sat, 22 Aug 2009 09:32:43 -0400, "mmc" wrote: "Andrew Erickson" wrote in message ... In article , wrote: On Fri, 21 Aug 2009 11:16:09 -0400, Andrew Erickson wrote: In article , wrote: On Thu, 20 Aug 2009 20:21:25 -0700 (PDT), Robin wrote: I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin How are you going to cool it adequately? I would assume, for an air-cooled engine, that's where the "adequate air circulation" comes in to play. One would probably have to be a bit careful not to push the engine too hard too long, as well, since many applications for these engines are not at steady high output. (There are exceptions--ultralight aircraft engines for one example.) I don't see any inherent insurmountable objections to doing this. A speed reduction of some sort would be nearly essential, of course, or else using a jet drive. Small two stroke engines in general tend to be inefficient and noisy and smelly and a bit temperamental, although the newer ones are vastly improved over older designs. On the other hand, they are lightweight and generally unaffected by being off level (limited mostly by the particular carburetor design), which can be advantages for use in a small boat. It's not as though there aren't a great many jet skis and boats with older outboards zipping around just fine with two stroke engines every day. Granted, most of these are water cooled, but still... There is a world of difference between a water cooled two-stroke, and an aircooled two-stroke, especially in a confined space. When I ask about cooling, it's because there will be a need for BIG fans to make this work. Air cooled motorcycles tend to overheat sitting in traffic. They need to keep moving to maintain reasonable temps. "Police Special" Harleys have a detuned and lower compression engine for this reason. Just being outside in open air is not enough. Put an engine like that as an inboard on a boat and you are in for trouble. It really needs to be addressed. I'm not sure it can be done practically. Snowmobile engines traditionally were air cooled two stroke engines (although more recently four stroke engines and liquid cooling have become common), and generally inside cowlings, and they generally manage to avoid overheating just fine. Likewise, chainsaw engines don't tend to overheat all the time, despite often being run rather hard. It's a question of the specific engine design (presumably based on the intended application), not a problem common to all two strokes. You are quite correct, though, that the original poster (should they attempt the conversion) should give some careful consideration to cooling. I don't think the end result would ever be an ideal boat motor, but I also think it could be perfectly adequate and probably a lot of fun if you're into that sort of thing. -- Andrew Erickson "He is no fool who gives what he cannot keep to gain that which he cannot lose." -- Jim Elliot Some small outboards were/are air cooled as well like the Sears Game Fishers, I think up to 5hp. Not even remotely the same thing as mounting an air cooled engine as an inboard. Err - the Honda 2 H.P. is an air cooled engine. Apparently has no problems with its cooling system. I had, and several friends presently have, air cooled 2-stroke, portable generators. Millions of lawn mowers are air cooled. I could go on but why bother. the O.P. already mentioned that he could foresee the problem of adequate air supply. What in the world is going to be a problem? Cheers, Bruce (bruceinbangkokatgmaildotcom) Man, if I were ever camped next to someone with a 2 smoke genset, they better also have a good supply of ammunition Why? The little 1 KW (actually 900-something watts) 2 stroke units, made in India by the way, run as quite as a 4-stroke. Not all 2-strokes have tunes exhaust. Uhm, Bruce, that turns out not to be the case. Think of the exhaust pipe as part of the intake system. These India units may be quieter than others, but the pipe is still tuned. I promise. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
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#29
posted to rec.boats.building
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Air cooled two stroke as inboard?
On Tue, 25 Aug 2009 07:00:46 +0700, Bruce In Bangkok
wrote: On Mon, 24 Aug 2009 12:01:01 -0400, JustWait wrote: In article , says... On Sat, 22 Aug 2009 10:36:47 -0400, wrote: On Sat, 22 Aug 2009 09:32:43 -0400, "mmc" wrote: "Andrew Erickson" wrote in message ... In article , wrote: On Fri, 21 Aug 2009 11:16:09 -0400, Andrew Erickson wrote: In article , wrote: On Thu, 20 Aug 2009 20:21:25 -0700 (PDT), Robin wrote: I had a brainwave the other day about putting a small (300cc) aircooled two stroke as an inboard in a small wooden boat. With adequate air circulation can anyone see any potential issues here? I would build the boat with this purpose in mind so adapting something to fit would not be a problem. Robin How are you going to cool it adequately? I would assume, for an air-cooled engine, that's where the "adequate air circulation" comes in to play. One would probably have to be a bit careful not to push the engine too hard too long, as well, since many applications for these engines are not at steady high output. (There are exceptions--ultralight aircraft engines for one example.) I don't see any inherent insurmountable objections to doing this. A speed reduction of some sort would be nearly essential, of course, or else using a jet drive. Small two stroke engines in general tend to be inefficient and noisy and smelly and a bit temperamental, although the newer ones are vastly improved over older designs. On the other hand, they are lightweight and generally unaffected by being off level (limited mostly by the particular carburetor design), which can be advantages for use in a small boat. It's not as though there aren't a great many jet skis and boats with older outboards zipping around just fine with two stroke engines every day. Granted, most of these are water cooled, but still... There is a world of difference between a water cooled two-stroke, and an aircooled two-stroke, especially in a confined space. When I ask about cooling, it's because there will be a need for BIG fans to make this work. Air cooled motorcycles tend to overheat sitting in traffic. They need to keep moving to maintain reasonable temps. "Police Special" Harleys have a detuned and lower compression engine for this reason. Just being outside in open air is not enough. Put an engine like that as an inboard on a boat and you are in for trouble. It really needs to be addressed. I'm not sure it can be done practically. Snowmobile engines traditionally were air cooled two stroke engines (although more recently four stroke engines and liquid cooling have become common), and generally inside cowlings, and they generally manage to avoid overheating just fine. Likewise, chainsaw engines don't tend to overheat all the time, despite often being run rather hard. It's a question of the specific engine design (presumably based on the intended application), not a problem common to all two strokes. You are quite correct, though, that the original poster (should they attempt the conversion) should give some careful consideration to cooling. I don't think the end result would ever be an ideal boat motor, but I also think it could be perfectly adequate and probably a lot of fun if you're into that sort of thing. -- Andrew Erickson "He is no fool who gives what he cannot keep to gain that which he cannot lose." -- Jim Elliot Some small outboards were/are air cooled as well like the Sears Game Fishers, I think up to 5hp. Not even remotely the same thing as mounting an air cooled engine as an inboard. Err - the Honda 2 H.P. is an air cooled engine. Apparently has no problems with its cooling system. I had, and several friends presently have, air cooled 2-stroke, portable generators. Millions of lawn mowers are air cooled. I could go on but why bother. the O.P. already mentioned that he could foresee the problem of adequate air supply. What in the world is going to be a problem? Cheers, Bruce (bruceinbangkokatgmaildotcom) Man, if I were ever camped next to someone with a 2 smoke genset, they better also have a good supply of ammunition Why? The little 1 KW (actually 900-something watts) 2 stroke units, made in India by the way, run as quite as a 4-stroke. Not all 2-strokes have tunes exhaust. Cheers, Bruce (bruceinbangkokatgmaildotcom) Correction: run as quiet as... Cheers, Bruce (bruceinbangkokatgmaildotcom) |
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#30
posted to rec.boats.building
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Air cooled two stroke as inboard?
I just don't remember ever seeing a two smoke lawnmower... Not doubting you, just started thinking about it and I was like... hummmmm, nope, just never saw one that I can remember.. Oooo weeeee! A buddy had one years ago. Smelly and smoky! |
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