Yeah I was thinking great I’ve never actually seen a head block milling machine I’m in for a treat. Then the disc grinder shows up. Got me good stu. Lol
Great to see you exploring a better cooling solution!! Just got back from Brupeg to remove the old engine. That was quite a job!! All the best from Surrey BC Canada
The mulitple camera angles and pov shots are great. I know it's time consuming when editing, but it's well worth it.👍 Looking forward to see more of these kinds of videos in the future.
Educational and entertaining. Laughed easily as much as I learnt. The concept of an adapter plate to return to normal makes me think of all the effort put into other adapters and kits on the market, particularly with engine conversions etc. With all your engineering knowledge and skill you should be up for an Engineering Doctorate at Sydney Uni. Thanks for the effort for filming, editing, teaching and entertaining us all.
So glad you're doing this, especially adding the heater I've been thinking on for so long. Means I can relax, lean back and not having to experiment with my own engine.. Too bad there are no Coopers here in northern Europe 🙂
Stu, Treat it as if it were a motorcycle, using the motorcycle radiator, you could mount it on the lower outside of the transom, a couple inches separating the tramsom from the radiator will insure adequate cooling.,just a thought! Love the idea.... Keep up the great work. I wait in anticipation for the the next great video.
Yes, have been considering that, not totally sold on the keel cooling idea yet. I actually have a wrecked motorcycle that I could pinch the radiator off too so that may well be the way to go!
Hi Stu, I hope you don’t mind, I referred you to a friend who has built a coaxial helicopter with an outboard engine as a power plant. He is suffering some cooling issues and this episode is just what the doctor ordered. Hope you don’t mind, but I think you are the best person with all the knowledge that I certainly am not up to date with this subject. Thanks
I've thought about doing this. 1 no more impeller changes and 2 I can run a cabin heater off it so many cheap 12v water pumps available now makes the idea very tempting
Several of my boats had "BUSS HEATERS" in them running of the v-8 I/O. We had year round fishing here on Canadian Westcoast and once hands got wet and cold it was game over.The heater was a great hand warmer! CHEERS from HERE!
I never thought about doing it on a smaller scale like you are presenting but it would definitely make your engines have a long service life when you are able to control the cooling medium. When I was still working in the Merchant Marine 20 years ago we used huge Shell and Tube heat exchangers and we used sacrificial zinc anodes on the saltwater side for our large EMD 645 20 cylinder and Sulzer 6 cylinder diesels. Periodically we would have to take down the heat exchangers and punch the tubes out due to the buildup on the saltwater side, but it kept the engines salt free and temperature controlled.
For what it's worth there's a guy in my area who's been experimenting with PEX tubing run in straight lines along the hull ever since that stuff came state-side. He swears by it since salt and water can't hurt it and holds up to insane amounts of heat. A single loop below the water line (a straight shot towards the bow, and a straight shot back towards the stern along the other side) seems to do the trick for all the 4cyl 4-strokers he's played with, up to about 80-100hp it's been pretty bulletproof
@@DangarMarine He did suggest anything 40ish horse or less, a whole motorcycle radiator, fan, inline filler & cap etc was the way to go if you have the space on your transom. Since the fan & shroud are already there already in a "puller" config and they're pretty robust and the fans off Honda bikes are surprisingly powerful and quiet. Just a nice pre-made ultra compact little setup that works well, a lot easier to rig up than bigger power keel cooling.. Over 80 horse won't work without a bigger radiator if you have the real estate, otherwise run your heat exchanger underwater. For tapping into the engine cooling circuit you're pretty on your own as they're all the same yet they're all completely different. He's got an older Evinrude he drilled & tapped for bungs.
this is basically how my friends boat air conditioner works, dosen't get "ice-cold" in the cabin and sleeping berths but keeps it all at a constant low temp (compared to the tropical temp outside) and use's very little power to achieve it (very low noise too :)
Drill and tap the intake and output. Plug extra outputs . Drill two hole in the lower cowling for the two hoses. You can test with a electric pump in a pail of water . Making it possible to check for flow and temperature. Will you be able to use copper pipe on a aluminum boat. With the inner action between the two metals. This looks like a great idea. Yes beer helps in planning.
Yes a step into the future, just a thought in to your idea of making a mid adapter slab: shaft length and exhaust cooling must be maintained, saying that - you will be using the original pump to cool the exhaust perhaps.
A block emd's 12/ 16 turbo and blown. Detroit 3/6/8/12/16 the stay clear! Done all this Fun stuff if I can pass knowledge I will smile! And my fun one was a cat 3512 a very fun learning experience. If we can think? We can!!
This project is brilliant. If the goal is to keep the characteristics of an outboard at the core of your solution, then my money says, it’s doomed to fail. Why? Because there are some major challenges that lie ahead. (Especially with a retrofit) The existing outboard cooling method is too efficient to improve upon. An enclosed system, by design, Introduces inefficiencies that will transform its tiny footprint into a donkey and cart. A current outboard is self contained, compact, almost portable (4 bolts); reliable, lightweight, efficient, and very cheap to manufacture, maintain, and operate. Flushing and impeller maintenance is all that is required to keep it functional. Fresh water use is best of course. May I be so bold as to say, there is no real problem to solve. ( or at least none to solve when operated correctly) The following features afforded by a raw water system, give us the outboard motor as we know it. An enclosed system cannot utilise them. 1- tiny coolant capillaries and low surface area requirements of coolant/.material tho be cooked. (This is only possible because of a low pressure, fast coolant flow, and a low coolant temperature environment) This environment is the plat opposite of an enclosed system. 2. Raw water cooling in an outboard has a coolant lifecycle that is way more efficient than enclosed. It uses the unlimited raw water efficiently. If fact, it is too efficient and needs to continually uses thermostats, and poppet valves throughout the engines run cycle to raise the temperature of the cylinders to maintain optimal combustion conditions. (Cars do this type of temp management on startup only). The raw water coolant lifecycle is as follows… Cold water in, water gets warmer through the power head, water becomes hot over the exhaust manifold then is expelled. The last stage of the coolant lifecycle (exhaust manifold )is where the outboard temperature is predominately managed. The coolant needs to be hot enough to not damage the manifold, therefore when it has passed through the manifold cooling stage, the coolant is too hot and the flow is now slow, free and lush. Then bye bye into the sea or lake it goes. Good luck managing the coolant from here to cool it efficiently enough to pass back through to the first stage of an enclosed recirculated system. Here comes the next stage of complexity and cost.
Brilliant concept. I wonder if there exists some data on btu created for a given horsepower from which we could make an educated guess on the size of keel cooler needed. I’m gonna guess that coolant fluid capacity will be key. More capacity may substitute for slower moving coolant.
When I first thought up my heater idea, I had planned to just run some of the spent cooling water through a heater core, leaving the rest of the engine cooling alone. But realistically that water usually isn't hot enough to make use of. Unless you could put hotter thermostats in or something like that, but I like your idea of a fully closed system. Very curious to see what you make of it!
Yes, have been thinking something similar. Just run it up to the top of the leg and let it flow back down. Having said that, I really can't see the exhaust getting that hot on a little outboard like this.
@@DangarMarine it will get hot enough to torch the paint off the leg , that little outboard will be working hard , near hot enough to melt the inner exhaust tube, be interesting to see the egt at the midsection after it exits the cooled manifold
With the 'telltale's lines - I would suggest having 'clear' bulb windows so that you can visually see the water is flowing - pressure sensors may not be reliable at the low pressure. I would then feed them back into the main line back to cooler locally at the engine - this would reduce the chances of springing a leak on those runs, and/or keep the leaks 'ouboard'.
Could you demonstrate how to set up the rollers on a boat trailer. I’ve been towing on gravel roads and mine are out of alignment. Would like to know how to reset. Or servicing a boat trailer?
Hello Stu. Really interesting project and I think you’re on the right tracks. I think the thermostat will direct the passage of water but not change the absolute amount so until the thermostat opens I expect the header tank will suffice (esp as until the engine is at operating temp you’ll be well away from WOT or significant load and it’s load that equals fuel burn and this is what makes heat. On closed cooling I expect the thermostat will open faster than on open. Once the thermostat is open I expect it’s then a balance between heat gain from the engine and heat loss through the keel loop and it’s possible the system might struggle to keep up with the heat dissipation and keep cylinder head temps sensible. Thermostats aren’t binary but are balancing fluid and heat flow. It might be wise to operate without a thermostat for testing as I don’t think heating will be the issue, it’ll be cooling. As you say, it might be hard to cool the coolant as effectively as the somewhat infinite system that is an open one, but I really see the benefit of doing what you are building and I like the plate idea. Be really interesting to see what volume the impeller pump can shift, plus how much water ends up down the exhaust in the open system. I think that would be another significant heat soak. If I had to guess where the heat goes in an open system I’d say 75% cylinder head and via the thermostat, 20% down the exhaust and 5% via the tell-tale. Interesting!
Neat project, Stu do outboard legs need water down the exhaust to prevent overheating damage? If they do perhaps retain original waterpump and divert that water up a pipe and back down in the exhaust gasses.
Your idea for an adapter plate with as many of the connections inside as possible is a good one. A bit of machining, for sure, but neat solution, and it gets to the heart of the problem: It can be done, but is it sensible to do? Too many modifications and external fittings means too many places to fail. An adapter that contains all the various junctions and external fittings limits points of failure, and simplifies installation. Still wondering about the attachment to the heat exchanger- flex hose?
G'Day Stu,,Mate been thinking about this for a while,,any way,,use the motor water pump to cool heat exchanger,,and run seperate pump for coolant, Make small bracket and mount it behind motor leg,?
I've done mechanical engineering on oil and gas equipment. From what I remember of the process engineers (aka wizards) saying (aka greek), heat transfer is increased with higher velocities of both hot and cold streams. It also matters whether fluids are flowing same, opposite or cross directionally, even when separated by a tube wall. Didn't seem right to me but I never passed any classes in the dark arts. Anyway, when optimising a heat transfer system, there's a pretty fine balance between heat transfer capacity, pump size, tube diameter and tube length. I'm hoping for the non-optimal duct tape and WD-40 prototype though. If you've only got one outboard to risk melting, maybe you should start running some experiments with hot water flowing through copper tubes. Take an inlet and outlet temp reading and calculate how many joules of heat energy you can dissipate with different flow rates or velocities. Pump some river water through an esky as the water bath to keep it a steady temperature. Another problem with a single tube heat exchanger is that after some initial length, additional length isn't very efficient because the coolant is cooler so there's less temperature differential driving heat transfer which is why heat exchangers are typically a tube-bundle design - keeps the length to surface area ratio down. All depends on how much heat you have to dissipate and the good news is water on the ambient side will absorb heat faster than air would. Bootleggers don't need too much copper pipe or water flow to condense ethanol vapour into moonshine.
@@DangarMarine the more I think about it, some sort of labrynth milled into a pair of plates would be a reasonable design for the keel cooler. Copper would be anti-fouling but galvanic against an aluminium hull without proper consideration. I like a plate design because it has a large mounting surface if you want to be brave and essentially glue (maybe a phenolic resin) it to the hull, and the leading edge might be shape-able to reduce drag/ eliminate cavitation if you're going faster than 2 kt. The outer plate could be milled with a shallow fin design for surface area to make up for not having all around contact with the cool water like a tube would. Extending the plate aft of the transom could keep any tube connections from the engine and expansion tank out of the turbulent water. The commercial units appear to be a through-hull fitting which I assume you're avoiding as it's an outboard engine so there are no other reasons to have holes in the hull.
Hey Stu, great Project! Looking forward to see the next episode. Instead of outboard cooling pipes did you ever think about installing inboard water pockets? like thin tanks inside the boat that transfer the heat via the big surface of the hull? You‘d have less drag and for those who need a partial „floor heating“ … well sort of😎
@@DangarMarine what about three or four rather small tanks between the Aluminium stringers in the boat? Each with a thermostat output that leads either back or to the engine or to the next tank. might be a new way. at least i’ve never seen it done that way before…wich doesn’t mean anything, at all, by the way…😎🤟🏻
An interesting vlog Stu, I'm puzzled why the outboard manufacturers don't use a sealed cooling system that circulates through the lower unit to dissipate the heat, fins could be added to the lower unit below the water line to achieve the required heat transfer.
M dot X cp X delta t is the formula for a heat exchanger. M dot is mass flow rate of the fluid moving, cp is specific heat of the fluid, and delta t is the temperature difference that can be required. Equal both of these together for each side of the heat exchanger fluid.
Have you thought of just using the original water pump to pump the raw water through the heat exchanger? May be better if you don’t have power on board to run an external pump Love the channel and think Adrian is an asset to!
It might make the plumbing simpler if you don't pass the full flow though the header tank. All you need is a small swirl pot to separate any air and provide a small amount of expansion volume. Small tube from the high point in the cooling system to the top of the pot and one from the bottom of the pot to the pump inlet. Also the leg pump volume can be calculated fairly easily, difference in area between a folded and unfolded vane times speed.
I was shocked you were doing this. Really cool though. Here is why I am shocked. Sharing what I did. I needed an small outboard. I didn't want one with an shifter. An clutch. Problem at idle. The water pump doesn't work. I fish fresh water. I put on into the system an 12v Is submergerable water pump. So no matter water I have water flow. I just put an tee between where the water line comes up into the housing and before it goes into the motor. So I can idle. Works. Yet I am excited to see what you do. Just sharing. 3.5hp motor. 2 cycle. Oh I also put an shut off valve on it as well. It's an fuel shut off but works. It runs with both at the same time. I just leave it on. Yet I see your point perfectly. Where no water from an lake or ocean. Okay. Makes perfect sense.
Adaptor plate method will also require a longer driveshaft to match the extra thickness of the adaptor plate. Also, don't overlook the need for exhaust cooling that would've been done by expelling the original raw water out through the prop👍🇦🇺
exhaust/tail section cooling, I am 5 minuntes in and I am already missing that bit. The tail section of the outboard will get hot as hell caused by the exhaust gasses. Grease and oil in the tail will not like that.
Don't forget that water can flow through the engine too quickly causing the engine to overheat, because the coolant must stay in contact with the metal long enough to exchange it's heat to the coolant. Find a pump that matches the engine's sweet spot, (basically the maximum volume of the original pump at full throttle), then slow down the coolant through the heat exchanger by using a larger tubing such as 13 mil versus the 10 mil of the inlet. I haven't got a clue as to how you will cool the exhaust with the closed system without some very fancy fabricating. Best of luck with it!🍺🍺🍺
Yep, excellent point about changing the diameter to change the speed. I've also been thinking that the pump always pushes 25 deg C water through but we will be circulating water that is around 90 deg C. If will definitely take some experimenting to get it right.
Whatever intake you have for raw water..is a weak point that can be blocked. A static run of copper tubing up to the bow on one side of the keel and back down the other side of the keel....uses "raw" water on the outside of the tubing to cool the engine coolant....but requires no inlet, strainer, grille or hole to plug up...and no pump..... But to cool the exhaust and the gearbox in the leg...that will require a pump or a scoop anyway......
How about cooling the fresh water in the leg with a coiled copper tubing and using the lower unit pump to circulate around the tubing having a closed system on fresh but open on salt ? Maintaining the original look of the outboard . Use 2 impeller pumps , 1 for salt and 1 for fresh ran on the drive shaft of the outboard
could you take the off the shelf coolers used for mercruisers & a davies craig EWP & route to the in/out of the engine? Have you allowed any considerations for some engines using the water flow as cooling for the gearbox? And yes, can get a heat exchanger for Inboard & I/O to use for heating, such as hot water tanks etc :)
I would wonder about the exhaust cooling in the leg. I know some outboards exhaust thru the prop but older 2 strokes up higher on the leg not under water like newer 4 strokes do. I like the idea of using a heater coil, get both heat and help dissipate engine heat.
Oh yeah it is needed, to cool the water pump housing, as the Pump is often used to keep the Upper Bearings in place and is where the Driveshaft Seals, and they too can't be overheated. Also the upper gearcase, and if the motor has Thru the Hub Exhaust, to keep the Rubber Hub from being burnt.
@@Phillv8 I'm surprised Stu missed/overlooked the cooling of the exhaust. Plugging the exiting water tube at the top, and drilling a couple of holes in it up there would provide the coolant needed
Is the water flow at the water pump used to lubricate the shaft? If so could you pipe your coolant down to the raw water intake and use that pump rather than an external pump?
Stu, some older snowmobiles used a very similar cooling system, coolant runs through heat exchangers that are positioned in the track tunnel so that snow is thrown up onto it. P.S. for those Aussies that may be reading this, snow is frozen water that falls from the sky in the form of a fluffy solid and covers the ground. Snowmobiles are what rednecks use to travel over snow, usually very drunk and way faster than is safe to do so. Think jetski minus the hot bikini clad sheila but instead with an obese man wearing a space suit.
Interesting project, and great for all those early 2000's "Asprin" 4 strokes that dissolve in salt water ;) I like the idea of a thick base plate, but would you then need to lengthen the drive shaft?
Hi. I’m trying to figure out what the shaft size and thread type is on my 1991 90HP 2 stroke flywheel is. The Nut is missing and I’m trying to find another. Any idea?
I Have been playing around with this concept for a while, My design will use the standard waterpump to deliver raw water to a expansion tank that has inter coils inside the tank, the sealed coolent from the powerhead would go thru the coils " Heat exchanger to b cooled. Because of thr temperatue differences this should cause the water in the block to flow. kodibass
Stu, any thought as to melting the lower engine crank shaft seal with out water jet cooling? That now dry exhaust is going to burn it all up along with the paint work on the leg , and the pivot grease, under a running heated load. looking forward to the progress. Or are you saving the original internal pump to dedicate towards the exhaust cooling inside the leg?
Love the thinking but wonder on economics. Are well made marine alloys well able to take SW vs closed ID flushed or if not. Flushing difficult in many areas asvFW not available so I'm interested why big commercials haven't researched this for that market. Many use diesel outboard or mini prop . Slow as hell but durable and can run off coconut oil locally made and often sail supplement. Mainly interisland transport and fishing handline bottom or smaller tuna . It would be great if a way to help tens of thousands without FW dock access if they could double internals life. Example my Chevy pickup probably go 300k with reg maintenance but if SW run through it doubt it make it half way . Apply to small boat engine for subsidence fisherman and a huge potential savings . Eg you could run double time sharing a boat at same lifespan but feed two families. Well I enjoy all your work as obviously many do and you inspire more thinking. I often wonder about electric too and some sort ofvenergy recapture if drift fishing and solar. Again thinking of our less fortunate relying on slow but stable power to live in rough environments with more limited resources and a real need for local fuels like coconut oil and sun. A few miles offshore at 5bkts top gets you a boatload of fish in half a day when running. Salt and dry for bad weather. Sweet potato coconut pandanus breadfruit and poultry swine but nothing like fresh fish!
The idea of an aluminum spacer plate could definitely work easily if the engine model come with different length shafts/legs because then you can just make the plate the same thickness to make up the difference of the leg and use the the shaft out of the longer leg. Gonna be interesting for sure.
🤔 A flat-plate counter-flow heat exchanger could take the heat from an outboard and use it to produce heat and/or hot water🤔 A hybrid pair of outboards - one gas, one electric 🤔 Could recharge its own batteries on the run 🤔 Heated handrails are a possibility 🙂 It's all in how you control the exchanges. Good stuff with lots of possibilities.
@@DangarMarine They have them on the fishing boats up north. Everything freezes. We stood on gunny-sacks for traction. Baits froze on the hook. A heated handrail and a warm cabin was a blessing when fishing for cod in January 🙂off Montauk N.Y. which is a fishing mecca, in case you don't know. Now I have a propane heater for my Aluminum drift boat which cannot burn 🙂
I love that hand-held bridgeport milling machine.
Yeah I was thinking great I’ve never actually seen a head block milling machine I’m in for a treat. Then the disc grinder shows up. Got me good stu. Lol
Thanks mate. It wasn't their top-of-the-line model but I'm still very fortunate to have it. ;)
I will never tire of Stu's subtle humor.
Surprised to see just how small the engine water passages are. I can see how easy it would be to plug one. Thanks Stu for showing this.
They aren't big, that's for sure. It isn't hard to see how they get blocked.
Got to admire a man who talks to his birds...
Great to see you exploring a better cooling solution!! Just got back from Brupeg to remove the old engine. That was quite a job!!
All the best from Surrey BC Canada
Thanks Dennis. I’m looking forward to seeing how it turns out!
The mulitple camera angles and pov shots are great. I know it's time consuming when editing, but it's well worth it.👍
Looking forward to see more of these kinds of videos in the future.
Thanks mate, glad you like it!
I’m very interested to see the completed project. It’s an interesting idea. Especially for the salt water bound folks.
Thanks mate. I think it will be a good upgrate for island boats where flushing them isn't really possible.
Educational and entertaining. Laughed easily as much as I learnt. The concept of an adapter plate to return to normal makes me think of all the effort put into other adapters and kits on the market, particularly with engine conversions etc. With all your engineering knowledge and skill you should be up for an Engineering Doctorate at Sydney Uni. Thanks for the effort for filming, editing, teaching and entertaining us all.
Thanks Scott. There are definitely challenges to the plate arrangement but I do like the idea of the installation being non-desctructive.
So glad you're doing this, especially adding the heater I've been thinking on for so long. Means I can relax, lean back and not having to experiment with my own engine.. Too bad there are no Coopers here in northern Europe 🙂
Hope we come up with a solution for you!
@@DangarMarine Might be hard, at least expensive to get the Coopers through customs but I sure appreciate your effort!
Stu, Treat it as if it were a motorcycle, using the motorcycle radiator, you could mount it on the lower outside of the transom, a couple inches separating the tramsom from the radiator will insure adequate cooling.,just a thought! Love the idea.... Keep up the great work. I wait in anticipation for the the next great video.
Yes, have been considering that, not totally sold on the keel cooling idea yet. I actually have a wrecked motorcycle that I could pinch the radiator off too so that may well be the way to go!
Hahaha love your portable milling machine Stu,,, hahaha,,, how many coopers did you find,,, 6 pack????
I like the project. I recommend that you leave the original pump in operation to cool the exhaust gases.
2:00 how very reminiscent of your videos where you used to give us "chalk talks" on the whiteboard at your old shop!
I like what you do mate
I m following you from Tunisia
Great idea
I did learn a lot from Ur videos
Thank u so much
Love your milling machine, Great to see a sense of humour,
What an interesting concept! I look forward to seeing the results
Thanks Pearce.
This is an interesting project. Looking forward to watching it progress.
Thanks!
Also we call them grid coolers. On the side's. I'm a Texas man so ? Think! You are great 👍
Hi Stu, I hope you don’t mind, I referred you to a friend who has built a coaxial helicopter with an outboard engine as a power plant. He is suffering some cooling issues and this episode is just what the doctor ordered. Hope you don’t mind, but I think you are the best person with all the knowledge that I certainly am not up to date with this subject. Thanks
Sounds like an interesting project he's doing!
BTD 1982 ?
@@alan-sk7ky 100% correct! He’s doing well but the nagging overheating is still an issue. Stu is the best one to understand the problem.
I've thought about doing this. 1 no more impeller changes and 2 I can run a cabin heater off it so many cheap 12v water pumps available now makes the idea very tempting
Very interesting project.
This is really interesting! How big to make the water pump and the raw water "keel cooler" pipe loop will be the most interesting issues.
Several of my boats had "BUSS HEATERS" in them running of the v-8 I/O. We had year round fishing here on Canadian Westcoast and once hands got wet and cold it was game over.The heater was a great hand warmer! CHEERS from HERE!
A heater does sound like a good thing to have for a winter fishing trip.
Wanted to do this for years.
Me too!
Looking forward to the results. Nice one Stu. Keel cooled hydrofoil wings?
This is the best episode in a long time! :D
Hey mate
Doesn’t the exhaust need to be cooled by water or the leg would get hot
clever idea
Can't wait to see the completed project.
Thanks Jimmy. :)
I never thought about doing it on a smaller scale like you are presenting but it would definitely make your engines have a long service life when you are able to control the cooling medium. When I was still working in the Merchant Marine 20 years ago we used huge Shell and Tube heat exchangers and we used sacrificial zinc anodes on the saltwater side for our large EMD 645 20 cylinder and Sulzer 6 cylinder diesels. Periodically we would have to take down the heat exchangers and punch the tubes out due to the buildup on the saltwater side, but it kept the engines salt free and temperature controlled.
Great video as always. Love the outro; Stu, the bird whisperer… 🦅
Awesome, thank you!
Really good idea especially the heater.
For what it's worth there's a guy in my area who's been experimenting with PEX tubing run in straight lines along the hull ever since that stuff came state-side. He swears by it since salt and water can't hurt it and holds up to insane amounts of heat. A single loop below the water line (a straight shot towards the bow, and a straight shot back towards the stern along the other side) seems to do the trick for all the 4cyl 4-strokers he's played with, up to about 80-100hp it's been pretty bulletproof
Thanks David, appreciate the info!
@@DangarMarine He did suggest anything 40ish horse or less, a whole motorcycle radiator, fan, inline filler & cap etc was the way to go if you have the space on your transom. Since the fan & shroud are already there already in a "puller" config and they're pretty robust and the fans off Honda bikes are surprisingly powerful and quiet. Just a nice pre-made ultra compact little setup that works well, a lot easier to rig up than bigger power keel cooling.. Over 80 horse won't work without a bigger radiator if you have the real estate, otherwise run your heat exchanger underwater. For tapping into the engine cooling circuit you're pretty on your own as they're all the same yet they're all completely different. He's got an older Evinrude he drilled & tapped for bungs.
this is basically how my friends boat air conditioner works, dosen't get "ice-cold" in the cabin and sleeping berths but keeps it all at a constant low temp (compared to the tropical temp outside) and use's very little power to achieve it (very low noise too :)
Your like the "Vice Grip Garage " of Australia, Love all your video's.
Top start up Stu 👍🏻 we needed that 😅
Thanks Colin!
Love the Emergency 10mm Socket, Stu! LOL
the beard suits you, kind of like a boat motor jesus, i dig it!
Drill and tap the intake and output. Plug extra outputs . Drill two hole in the lower cowling for the two hoses. You can test with a electric pump in a pail of water . Making it possible to check for flow and temperature.
Will you be able to use copper pipe on a aluminum boat. With the inner action between the two metals.
This looks like a great idea. Yes beer helps in planning.
I don’t give you a penny. But I will give you a tummy upp in your show town.❤ fan Sweden 🇸🇪
That milling machine is tops
Yes a step into the future, just a thought in to your idea of making a mid adapter slab: shaft length and exhaust cooling must be maintained, saying that - you will be using the original pump to cool the exhaust perhaps.
LOOKIN' GOOD. KEEP SAFE...
A block emd's 12/ 16 turbo and blown. Detroit 3/6/8/12/16 the stay clear! Done all this Fun stuff if I can pass knowledge I will smile! And my fun one was a cat 3512 a very fun learning experience. If we can think? We can!!
Thanks David!
This project is brilliant. If the goal is to keep the characteristics of an outboard at the core of your solution, then my money says, it’s doomed to fail. Why? Because there are some major challenges that lie ahead. (Especially with a retrofit)
The existing outboard cooling method is too efficient to improve upon. An enclosed system, by design, Introduces inefficiencies that will transform its tiny footprint into a donkey and cart.
A current outboard is self contained, compact, almost portable (4 bolts); reliable, lightweight, efficient, and very cheap to manufacture, maintain, and operate. Flushing and impeller maintenance is all that is required to keep it functional. Fresh water use is best of course. May I be so bold as to say, there is no real problem to solve. ( or at least none to solve when operated correctly)
The following features afforded by a raw water system, give us the outboard motor as we know it. An enclosed system cannot utilise them.
1- tiny coolant capillaries and low surface area requirements of coolant/.material tho be cooked. (This is only possible because of a low pressure, fast coolant flow, and a low coolant temperature environment) This environment is the plat opposite of an enclosed system.
2. Raw water cooling in an outboard has a coolant lifecycle that is way more efficient than enclosed. It uses the unlimited raw water efficiently. If fact, it is too efficient and needs to continually uses thermostats, and poppet valves throughout the engines run cycle to raise the temperature of the cylinders to maintain optimal combustion conditions. (Cars do this type of temp management on startup only).
The raw water coolant lifecycle is as follows… Cold water in, water gets warmer through the power head, water becomes hot over the exhaust manifold then is expelled. The last stage of the coolant lifecycle (exhaust manifold )is where the outboard temperature is predominately managed. The coolant needs to be hot enough to not damage the manifold, therefore when it has passed through the manifold cooling stage, the coolant is too hot and the flow is now slow, free and lush. Then bye bye into the sea or lake it goes.
Good luck managing the coolant from here to cool it efficiently enough to pass back through to the first stage of an enclosed recirculated system. Here comes the next stage of complexity and cost.
They make themselves feel at home, these birds!
They do!
Brilliant concept. I wonder if there exists some data on btu created for a given horsepower from which we could make an educated guess on the size of keel cooler needed. I’m gonna guess that coolant fluid capacity will be key. More capacity may substitute for slower moving coolant.
What about cooling the exhaust in the leg so you don’t burn up the mid section or seals in the top of the gearbox
Very good point
Love the milling machine
When I first thought up my heater idea, I had planned to just run some of the spent cooling water through a heater core, leaving the rest of the engine cooling alone. But realistically that water usually isn't hot enough to make use of. Unless you could put hotter thermostats in or something like that, but I like your idea of a fully closed system. Very curious to see what you make of it!
Thanks for the class.
You are welcome!
Could you use a tunnel heat exchanger from a snowmobile?
How about utilising the raw water pump to inject into the exhaust gasses as high as possible to keep the midsection cool ???
Yes, have been thinking something similar. Just run it up to the top of the leg and let it flow back down. Having said that, I really can't see the exhaust getting that hot on a little outboard like this.
@@DangarMarine it will get hot enough to torch the paint off the leg , that little outboard will be working hard , near hot enough to melt the inner exhaust tube, be interesting to see the egt at the midsection after it exits the cooled manifold
🤣🤣🤣 love that mill Stu. That made my arvo.
So cool i aleays thought about this as well intresting to see how it goes :)
Thank you Stu ;)
No worries!
Funny to see this video pop up, while flushing my motor couple if days ago was thinking of ways to do somethi g like this
With the 'telltale's lines - I would suggest having 'clear' bulb windows so that you can visually see the water is flowing - pressure sensors may not be reliable at the low pressure. I would then feed them back into the main line back to cooler locally at the engine - this would reduce the chances of springing a leak on those runs, and/or keep the leaks 'ouboard'.
Could you demonstrate how to set up the rollers on a boat trailer. I’ve been towing on gravel roads and mine are out of alignment. Would like to know how to reset.
Or servicing a boat trailer?
Hello Stu.
Really interesting project and I think you’re on the right tracks. I think the thermostat will direct the passage of water but not change the absolute amount so until the thermostat opens I expect the header tank will suffice (esp as until the engine is at operating temp you’ll be well away from WOT or significant load and it’s load that equals fuel burn and this is what makes heat.
On closed cooling I expect the thermostat will open faster than on open. Once the thermostat is open I expect it’s then a balance between heat gain from the engine and heat loss through the keel loop and it’s possible the system might struggle to keep up with the heat dissipation and keep cylinder head temps sensible. Thermostats aren’t binary but are balancing fluid and heat flow. It might be wise to operate without a thermostat for testing as I don’t think heating will be the issue, it’ll be cooling.
As you say, it might be hard to cool the coolant as effectively as the somewhat infinite system that is an open one, but I really see the benefit of doing what you are building and I like the plate idea. Be really interesting to see what volume the impeller pump can shift, plus how much water ends up down the exhaust in the open system. I think that would be another significant heat soak.
If I had to guess where the heat goes in an open system I’d say 75% cylinder head and via the thermostat, 20% down the exhaust and 5% via the tell-tale.
Interesting!
Put me down for one of the kits when they come out :)
This is fun!
Neat project, Stu do outboard legs need water down the exhaust to prevent overheating damage? If they do perhaps retain original waterpump and divert that water up a pipe and back down in the exhaust gasses.
Your idea for an adapter plate with as many of the connections inside as possible is a good one. A bit of machining, for sure, but neat solution, and it gets to the heart of the problem: It can be done, but is it sensible to do? Too many modifications and external fittings means too many places to fail. An adapter that contains all the various junctions and external fittings limits points of failure, and simplifies installation. Still wondering about the attachment to the heat exchanger- flex hose?
Yes, flex hose for the attachment to the heat exchanged. Thinking it would be best to group the with the fuel hose as a loom of three.
Very interesting mate!
Power it with Propane-Propane...Propane-Propane...
@@alan-sk7ky hahahah
G'Day Stu,,Mate been thinking about this for a while,,any way,,use the motor water pump to cool heat exchanger,,and run seperate pump for coolant,
Make small bracket and mount it behind motor leg,?
That's definitely one option on the table.
How are you going to cool the exhaust/area with water diverted? Perhaps utilize the regular water pump's output pipe to just flow water there?
Can't wait to see the project! what exactly do you do in IT?
Software development.
I've done mechanical engineering on oil and gas equipment. From what I remember of the process engineers (aka wizards) saying (aka greek), heat transfer is increased with higher velocities of both hot and cold streams. It also matters whether fluids are flowing same, opposite or cross directionally, even when separated by a tube wall. Didn't seem right to me but I never passed any classes in the dark arts.
Anyway, when optimising a heat transfer system, there's a pretty fine balance between heat transfer capacity, pump size, tube diameter and tube length.
I'm hoping for the non-optimal duct tape and WD-40 prototype though.
If you've only got one outboard to risk melting, maybe you should start running some experiments with hot water flowing through copper tubes. Take an inlet and outlet temp reading and calculate how many joules of heat energy you can dissipate with different flow rates or velocities. Pump some river water through an esky as the water bath to keep it a steady temperature.
Another problem with a single tube heat exchanger is that after some initial length, additional length isn't very efficient because the coolant is cooler so there's less temperature differential driving heat transfer which is why heat exchangers are typically a tube-bundle design - keeps the length to surface area ratio down.
All depends on how much heat you have to dissipate and the good news is water on the ambient side will absorb heat faster than air would. Bootleggers don't need too much copper pipe or water flow to condense ethanol vapour into moonshine.
Great point about multiple short pipes being more effective that one long. Makes perfect sense.
@@DangarMarine the more I think about it, some sort of labrynth milled into a pair of plates would be a reasonable design for the keel cooler. Copper would be anti-fouling but galvanic against an aluminium hull without proper consideration. I like a plate design because it has a large mounting surface if you want to be brave and essentially glue (maybe a phenolic resin) it to the hull, and the leading edge might be shape-able to reduce drag/ eliminate cavitation if you're going faster than 2 kt. The outer plate could be milled with a shallow fin design for surface area to make up for not having all around contact with the cool water like a tube would. Extending the plate aft of the transom could keep any tube connections from the engine and expansion tank out of the turbulent water. The commercial units appear to be a through-hull fitting which I assume you're avoiding as it's an outboard engine so there are no other reasons to have holes in the hull.
Hey Stu, great Project!
Looking forward to see the next episode.
Instead of outboard cooling pipes did you ever think about installing inboard water pockets? like thin tanks inside the boat that transfer the heat via the big surface of the hull? You‘d have less drag and for those who need a partial „floor heating“ … well sort of😎
Yes, have definitely been looking into that. Thinking either C channel welded to the inside or a large sink tank. Lots of research to do!
@@DangarMarine what about three or four rather small tanks between the Aluminium stringers in the boat? Each with a thermostat output that leads either back or to the engine or to the next tank. might be a new way. at least i’ve never seen it done that way before…wich doesn’t mean anything, at all, by the way…😎🤟🏻
Bugger the outboards, show us more cute snakes ... 😜 Seriously, you do great videos mate, thanks .. 👍
An interesting vlog Stu, I'm puzzled why the outboard manufacturers don't use a sealed cooling system that circulates through the lower unit to dissipate the heat, fins could be added to the lower unit below the water line to achieve the required heat transfer.
Far too little surface area, I imagine.
Thanks Paul, it will be interesting to see how much cooling is required for this outboard and how compact it can be made.
M dot X cp X delta t is the formula for a heat exchanger. M dot is mass flow rate of the fluid moving, cp is specific heat of the fluid, and delta t is the temperature difference that can be required. Equal both of these together for each side of the heat exchanger fluid.
Sorry mate looks like l am 2 days late 🥵🤧😵☹.....Best of luck on this kind of cooling on an outboard 👀👍
Shoe🇺🇸
Have you thought of just using the original water pump to pump the raw water through the heat exchanger?
May be better if you don’t have power on board to run an external pump
Love the channel and think Adrian is an asset to!
You would still need an external pump to push the coolant through the heat exchanger even if the original pump was pushing the raw water.
It might make the plumbing simpler if you don't pass the full flow though the header tank. All you need is a small swirl pot to separate any air and provide a small amount of expansion volume. Small tube from the high point in the cooling system to the top of the pot and one from the bottom of the pot to the pump inlet. Also the leg pump volume can be calculated fairly easily, difference in area between a folded and unfolded vane times speed.
I was shocked you were doing this. Really cool though. Here is why I am shocked. Sharing what I did. I needed an small outboard. I didn't want one with an shifter. An clutch. Problem at idle. The water pump doesn't work. I fish fresh water. I put on into the system an 12v Is submergerable water pump. So no matter water I have water flow. I just put an tee between where the water line comes up into the housing and before it goes into the motor. So I can idle. Works. Yet I am excited to see what you do. Just sharing. 3.5hp motor. 2 cycle. Oh I also put an shut off valve on it as well. It's an fuel shut off but works. It runs with both at the same time. I just leave it on. Yet I see your point perfectly. Where no water from an lake or ocean. Okay. Makes perfect sense.
Adaptor plate method will also require a longer driveshaft to match the extra thickness of the adaptor plate. Also, don't overlook the need for exhaust cooling that would've been done by expelling the original raw water out through the prop👍🇦🇺
exhaust/tail section cooling, I am 5 minuntes in and I am already missing that bit. The tail section of the outboard will get hot as hell caused by the exhaust gasses. Grease and oil in the tail will not like that.
Good point about the driveshaft (and gear selector) length. Looks like it might be easier just to tap in directly.
Hasn't got an oxy torch there at the moment, but fortunately he has a cylinder block milling machine.
Great vid as usuall!
Don't forget that water can flow through the engine too quickly causing the engine to overheat, because the coolant must stay in contact with the metal long enough to exchange it's heat to the coolant. Find a pump that matches the engine's sweet spot, (basically the maximum volume of the original pump at full throttle), then slow down the coolant through the heat exchanger by using a larger tubing such as 13 mil versus the 10 mil of the inlet. I haven't got a clue as to how you will cool the exhaust with the closed system without some very fancy fabricating. Best of luck with it!🍺🍺🍺
Yep, excellent point about changing the diameter to change the speed. I've also been thinking that the pump always pushes 25 deg C water through but we will be circulating water that is around 90 deg C. If will definitely take some experimenting to get it right.
Could you put a tight multi coil hx inside the leg cavity and use the original pump to pass raw water over it, keep it all self contained
Possibly! That's a nice idea to keep it all very compact and self contained.
Whatever intake you have for raw water..is a weak point that can be blocked.
A static run of copper tubing up to the bow on one side of the keel and back down the other side of the keel....uses "raw" water on the outside of the tubing to cool the engine coolant....but requires no inlet, strainer, grille or hole to plug up...and no pump.....
But to cool the exhaust and the gearbox in the leg...that will require a pump or a scoop anyway......
My thought would be to keep the raw water pump and weld covers over the raw water intakes on the leg. Inlet side and pump handled. Return side ??
Must have been quite a few Coopers on Renko I reckon.
How about cooling the fresh water in the leg with a coiled copper tubing and using the lower unit pump to circulate around the tubing having a closed system on fresh but open on salt ? Maintaining the original look of the outboard . Use 2 impeller pumps , 1 for salt and 1 for fresh ran on the drive shaft of the outboard
Have been thinking about that, definitely still one option that is on the table.
could you take the off the shelf coolers used for mercruisers & a davies craig EWP & route to the in/out of the engine? Have you allowed any considerations for some engines using the water flow as cooling for the gearbox? And yes, can get a heat exchanger for Inboard & I/O to use for heating, such as hot water tanks etc :)
Look up keel or channel or grid cooling on a tow oat in America. It may help in your hypothesis.
I would wonder about the exhaust cooling in the leg. I know some outboards exhaust thru the prop but older 2 strokes up higher on the leg not under water like newer 4 strokes do. I like the idea of using a heater coil, get both heat and help dissipate engine heat.
Could definitely still use the old impeller for exhaust cooling only.
Hi Stu,
Prob covered this somewhere, but wondering where you did you trade, and whether you did marine or light/heavy vehicle
How about the cooling for the exhaust? It normally runs the coolingwater to the exhaust, but is it needed?
Oh yeah it is needed, to cool the water pump housing, as the Pump is often used to keep the Upper Bearings in place and is where the Driveshaft Seals, and they too can't be overheated. Also the upper gearcase, and if the motor has Thru the Hub Exhaust, to keep the Rubber Hub from being burnt.
Seals would burn out in mins!
@@Phillv8
I'm surprised Stu missed/overlooked the cooling of the exhaust. Plugging the exiting water tube at the top, and drilling a couple of holes in it up there would provide the coolant needed
Will the outboard gaskets etc. Be able to handle the added pressure of a closed loop?
I can't see them failing at 5 or 6 psi.
I have started to skip the video and go right to the chickens, very rewarding. cheers
Is the water flow at the water pump used to lubricate the shaft? If so could you pipe your coolant down to the raw water intake and use that pump rather than an external pump?
Stu, some older snowmobiles used a very similar cooling system, coolant runs through heat exchangers that are positioned in the track tunnel so that snow is thrown up onto it.
P.S. for those Aussies that may be reading this, snow is frozen water that falls from the sky in the form of a fluffy solid and covers the ground. Snowmobiles are what rednecks use to travel over snow, usually very drunk and way faster than is safe to do so. Think jetski minus the hot bikini clad sheila but instead with an obese man wearing a space suit.
Interesting project, and great for all those early 2000's "Asprin" 4 strokes that dissolve in salt water ;) I like the idea of a thick base plate, but would you then need to lengthen the drive shaft?
Maybe use a 20 inch lower unit in a 15 inch leg and a 5 inch block? Will need a huge engine cowl though 🤣
Or cut down a long shaft...
Hi.
I’m trying to figure out what the shaft size and thread type is on my 1991 90HP 2 stroke flywheel is. The Nut is missing and I’m trying to find another.
Any idea?
Great vid!!! Thermodynamics = Fun Times!!!
I Have been playing around with this concept for a while, My design will use the standard waterpump to deliver raw water to a expansion tank that has inter coils inside the tank, the sealed coolent from the powerhead would go thru the coils " Heat exchanger to b cooled. Because of thr temperatue differences this should cause the water in the block to flow. kodibass
Stu, any thought as to melting the lower engine crank shaft seal with out water jet cooling? That now dry exhaust is going to burn it all up along with the paint work on the leg , and the pivot grease, under a running heated load. looking forward to the progress. Or are you saving the original internal pump to dedicate towards the exhaust cooling inside the leg?
Yes, thinking coolant through the engine and raw water for the exhaust.
Love the thinking but wonder on economics. Are well made marine alloys well able to take SW vs closed ID flushed or if not. Flushing difficult in many areas asvFW not available so I'm interested why big commercials haven't researched this for that market. Many use diesel outboard or mini prop . Slow as hell but durable and can run off coconut oil locally made and often sail supplement. Mainly interisland transport and fishing handline bottom or smaller tuna .
It would be great if a way to help tens of thousands without FW dock access if they could double internals life.
Example my Chevy pickup probably go 300k with reg maintenance but if SW run through it doubt it make it half way . Apply to small boat engine for subsidence fisherman and a huge potential savings . Eg you could run double time sharing a boat at same lifespan but feed two families.
Well I enjoy all your work as obviously many do and you inspire more thinking. I often wonder about electric too and some sort ofvenergy recapture if drift fishing and solar. Again thinking of our less fortunate relying on slow but stable power to live in rough environments with more limited resources and a real need for local fuels like coconut oil and sun. A few miles offshore at 5bkts top gets you a boatload of fish in half a day when running. Salt and dry for bad weather. Sweet potato coconut pandanus breadfruit and poultry swine but nothing like fresh fish!
The idea of an aluminum spacer plate could definitely work easily if the engine model come with different length shafts/legs because then you can just make the plate the same thickness to make up the difference of the leg and use the the shaft out of the longer leg. Gonna be interesting for sure.
Yes, not sure whether to replace the drive shaft with a longer one or add an extension adapter.
🤔 A flat-plate counter-flow heat exchanger could take the heat from an outboard and use it to produce heat and/or hot water🤔 A hybrid pair of outboards - one gas, one electric 🤔 Could recharge its own batteries on the run 🤔 Heated handrails are a possibility 🙂 It's all in how you control the exchanges. Good stuff with lots of possibilities.
I like the idea of headed hand rails. :)
@@DangarMarine They have them on the fishing boats up north. Everything freezes. We stood on gunny-sacks for traction. Baits froze on the hook. A heated handrail and a warm cabin was a blessing when fishing for cod in January 🙂off Montauk N.Y. which is a fishing mecca, in case you don't know.
Now I have a propane heater for my Aluminum drift boat which cannot burn 🙂