yanmar clone...slow speed water cooled conversion

[focodiesel]

Hello all, I found this site a few months ago and have been hooked ever since, which was natural since I love all things with diesel, power generation, and self sufficiency. Anyways to the point of my first post here...I know that there is a lot of brilliant minds here so I would like to hear feedback, more specifically the challenges that I would face to do the following: (this idea has been in my head for the last couple of weeks)
Take a yanmar L100 or clone (186fe), make a custom liquid cooled cylinder to replace the air cooled jug, which will utilize a yanmar l48 or clone (170f) piston and head. This would create a 70x72 bore and stroke. Next, attach one or two large flywheels, think lister. You would end up with a small liquid cooled, direct injected, slow spinning, under-square engine.
Why I think this would be a good motor if it's possible:
1. Parts availability for these engines is second to none, and cheap
2. Liquid cooled for combined heat and power (I'm thinking a wet sleeve design would be awesome)
3. A slow turning mini engine with big flywheels like a lister would just be too cool, and we all know the benefits to slower operation having far less parts wear.
4. Direct Injection, currently a similar size motor is the r170f/r175f, and maybe those small kubotas I'm not too familiar with, but they are all IDI so less efficient, recently though I have been thinking IDI isn't all bad if you are harvesting the heat, it just means it is more of a heater than an electric generator

Difficulties:
1. Air cooled design, cylinder head is air cooled how will that work with a liquid cooled cylinder? Can I make the air cooled head liquid cooled?
2. My original thoughts are aluminum outer cylinder with a cast iron wet sleeve, so making that all seal up with the aluminum block and head will take some engineering.
3. Will the connecting rod hit the longer cylinder?
4. Can the crank bearings support the large flywheels?
5. Balancing the new rotating assembly and flywheels, will the counterbalancing shaft complicate this?
6. Oiling, a common concern when we load engines at lower rpm's.

Anyways, let me know you thoughts on this so I can get a better idea of the feasibility of this harebrained idea.

[Derb]

Dont know about the restroking of the engine but water cooling is feasible. A mate of mine is into bucket racing (budget motorcycle racing with tight engine controls) and rather than go to a 250cc 4 stroke did a water cooledl conversion on a 125cc 2 stroke. He is failrly clever with small engines and figured that he could stop the huge power drop-off he was getting with his pretty "hot" 2 stroke when it was under long periods of high load by keeping the barrell and head at a more reasonable temperature. He jacketed the barrell and head individually and piped water barrell 1st then through the head and on to radiator. He used a 2nd hand pump off a motorcycle I think. I have seen this bike and the system worked and it went like stink. I think he drilled heaps of holes through the fins before argon welding the jackets on and used off-the-shelf motorcycle hoses and radiator. But it did work. The bike was never going to be asked to run for years driving a generator though.............?

[glort]

First thing I'm thinking is how much power you going to get out of it?

186 does 8.5 hp @ 3600 RPM and thats a fair bit oversize to what you are proposing.
How much do you want to slow this thing down? As RPM is a function of power and I don't think it's linear, You might be looking at 2-2.5 HP @ 1200 Rpm. Someone might correct that but I'm pretty sure that the end is a lot of work for very little power output.

Think about a lister, 1.4L for 6HP.  A medium size chainsaw will do that easily and you can hold that engine in one hand. The slow revs of the lister and the high revs of the chainsaw is what makes them compatible in output but different in every other way pretty much.

If you want slow revs with any decent power output, you are going to have to go up on the capacity to get any worthwhile useable power.
An awful lot of work for a very limited outpu both in heat and power. 
I think you would be better off just leaving the engine as is and reducing revs a bit and taking the heat off the exhaust ( which still won't be much)  or better still, just get a water cooled horizontal Diesel in the first place.

[Henry W]

Those engines run nicely between 2500-3000 rpm's. They are designed to run between 2500-3600 rpm's. They do not run well at lower speeds loaded. The manufactures put lots of time in R&D. I feel your intentions are good but it will be very hard to do better than OEM's. They have the money to stress them out, blow them up, run them under less than ideal conditions, ect, ect. Most of us do not have that privilege. I would look for a used engine that is already designed for your specific application and rebuild it.

Now the Kubota ea300, eb300, el300, ea330 engines are good candidates to look at. I see these engines on craigslist often. They are good engines, parts are available, I would not be to concerned that they are IDI. They are still more fuel efficient than most IDI's of the same size. Another plus is they are very quiet. I posted some info on this forum someplace, the el300 is set up to run at lower speeds at 2000 rpm's. Output is 4 Hp.

Henry

[focodiesel]

First thing I'm thinking is how much power you going to get out of it?

Well I suppose at 1500 rpm it would be about (off the top of my head) 2hp or 1kw

I'm pretty sure that the end is a lot of work for very little power output.

Yes but if my goal is to have that lower amount of output, it would be better than having an oversized engine cycling on and off. I use about 1-2kw on avg and that is including electric heat, once I start using other heat sources...wood, heat from generator, it would probably be more like 500-1000 watts continuous. Also I enjoy doing this sorta stuff, so that whole lotta' work will make it that much more rewarding if it is successful. Also I would not just do it as a one engine deal, I would maybe make them in batches and sell kits to others who wish to the conversion, or even complete engines.

If you want slow revs with any decent power output, you are going to have to go up on the capacity to get any worthwhile useable power.

displacement will be similar to the El300 and 165/170/175 changfas.

An awful lot of work for a very limited outpu both in heat and power. 
I think you would be better off just leaving the engine as is and reducing revs a bit and taking the heat off the exhaust ( which still won't be much)  or better still, just get a water cooled horizontal Diesel in the first place.

I actually just picked up a r170f, pretty awsome little engine, but on this side of the pond, parts are not as easy to get compared to the yanclones, and it's aircooled.

[focodiesel]

Those engines run nicely between 2500-3000 rpm's. They are designed to run between 2500-3600 rpm's. They do not run well at lower speeds loaded. The manufactures put lots of time in R&D. I feel your intentions are good but it will be very hard to do better than OEM's. They have the money to stress them out, blow them up, run them under less than ideal conditions, ect, ect. Most of us do not have that privilege. I would look for a used engine that is already designed for your specific application and rebuild it.

I plan on having a 170f (yanclone) and 186f in front of me and pullng them apart side by side, not a huge investment, < $1000, so I guess my main question is what specifically makes these engines only practical at 2500-3600 rpm?

Now the Kubota ea300, eb300, el300, ea330 engines are good candidates to look at. I see these engines on craigslist often. They are good engines, parts are available, I would not be to concerned that they are IDI. They are still more fuel efficient than most IDI's of the same size. Another plus is they are very quiet. I posted some info on this forum someplace, the el300 is set up to run at lower speeds at 2000 rpm's. Output is 4 Hp.

Henry

I don't know much about those little kubotas, but I'm sure they are high quality as all kubotas are, but I have never seen one locally on craigslist or ebay, are they common in marine applications? If so that would explain why none locally as I'm in Colorado. But also the fact that I'm not seeing any examples and almost no parts on ebay for them doesn't sit well with me. That would be the main advantage of making a slow speed liquid cooled yanmar, cheap parts and engines a plenty.

Thanks for the input so far, please keep it coming.

[Henry W]

Those engines run nicely between 2500-3000 rpm's. They are designed to run between 2500-3600 rpm's. They do not run well at lower speeds loaded. The manufactures put lots of time in R&D. I feel your intentions are good but it will be very hard to do better than OEM's. They have the money to stress them out, blow them up, run them under less than ideal conditions, ect, ect. Most of us do not have that privilege. I would look for a used engine that is already designed for your specific application and rebuild it.

I plan on having a 170f (yanclone) and 186f in front of me and pullng them apart side by side, not a huge investment, < $1000, so I guess my main question is what specifically makes these engines only practical at 2500-3600 rpm?

Now the Kubota ea300, eb300, el300, ea330 engines are good candidates to look at. I see these engines on craigslist often. They are good engines, parts are available, I would not be to concerned that they are IDI. They are still more fuel efficient than most IDI's of the same size. Another plus is they are very quiet. I posted some info on this forum someplace, the el300 is set up to run at lower speeds at 2000 rpm's. Output is 4 Hp.

Henry

I don't know much about those little kubotas, but I'm sure they are high quality as all kubotas are, but I have never seen one locally on craigslist or ebay, are they common in marine applications? If so that would explain why none locally as I'm in Colorado. But also the fact that I'm not seeing any examples and almost no parts on ebay for them doesn't sit well with me. That would be the main advantage of making a slow speed liquid cooled yanmar, cheap parts and engines a plenty.

Thanks for the input so far, please keep it coming.

There are number of reasons why 2500-3000 would be best for these engines.

Critical Engine Speed
The size of the crank and rod bearings
Flywheel mass
Oiling system
And the list goes on.

I been around these engines long enough to understand where they run best. At low speeds these engines exhibit some pretty nasty harmonics and this is called critical engine speed. You want to run these engines out of that rpm range. We ran Yanmar L70 and L100 engines on water pumps and some L70 engines blew up. The cause was running at low speeds. These engines like running where I specified and they will live a long life.

The crank to rod angle is not the best on lots of these small diesels and in turn it puts stress on piston skirts at low speeds. The stress is reduced by running at higher speeds. It is all about R&D.

You say you don't know much about the kubota's. They are a very well built engine. Much stronger built than the Yanmar air cooled engines. Heavier crankshaft, larger bearings, cast iron head, re-sleeve able cylinder, larger flywheel. Parts are available at any Kubota engine and parts distributer. And prices are not out of line. I pretty much buy all parts at a local engine distributer and prices are cheaper than Ebay.

Shipping engines has never been a problem. Look at freightquote.com.

If you want to check out where these engines like to be ran call up Yanmar or Kubota and speak to one of the application engineers.

I understand the  Yanmar clones are very cheap. But what you are thinking of, I cannot justify the time and cost.

There was a Kubota ea330 available not to long ago in Colorado. Just have to keep looking. It took me over a year to find the one I have.

Henry

[Henry W]

Focodiesel,
In your first post you lister flywheels. My guess is your talking about CS flywheels. The crank will not be able to support all that weight by itself safely. And then there is safe rim speed. It is not recommended and unsafe to exceed the safe rim speed.

Henry

[Henry W]

Some engines that are of interest to me are:

Volvo Penta MD1B

Bukh DV10

These engines can run slow.

[glort]

I'm pretty sure that the end is a lot of work for very little power output.

Yes but if my goal is to have that lower amount of output, it would be better than having an oversized engine cycling on and off. I use about 1-2kw on avg and that is including electric heat, once I start using other heat sources...wood, heat from generator, it would probably be more like 500-1000 watts continuous.

I'd suggest that -if- your power requirements are that low ( and I have read of very few people that are) then I would suggest you would be better off forgetting an engine and going with wind and or solar.  No fuel requirement, less maintenance and virtually never wears out.

IF you are grid connected, I'd say an oversize engine is exactly what you want. Couple it up to a 3 phase induction motor and do a run back feeding to the grid. If your power consumption is so low you might only have to run the thing once a week to make back all your power. If you are off grid, a battery bank would be better than having to go start the engine every so often so the fridge and freezer can kick in or having the engine run 24/7. If you have a battery bank, again better to pump it up faster than slower.

Also I enjoy doing this sorta stuff, so that whole lotta' work will make it that much more rewarding if it is successful. Also I would not just do it as a one engine deal, I would maybe make them in batches and sell kits to others who wish to the conversion, or even complete engines. 

I think you will need to be doing it for the enjoyment because I can't possibly see you recouping your investment in time or money trying to sell people 2 Hp engines.
If you look here, the overwhelming theme is getting more power, not less. While your requirements might be very low, thats different to most people.
I would assess your market very carefully if you wish to make any sort of financial return.

If you want slow revs with any decent power output, you are going to have to go up on the capacity to get any worthwhile useable power.

displacement will be similar to the El300 and 165/170/175 changfas.

Exactly. Which is why you will have such low output.  When was the last time you saw a 1KW alternator?

An awful lot of work for a very limited output both in heat and power. 
I think you would be better off just leaving the engine as is and reducing revs a bit and taking the heat off the exhaust ( which still won't be much)  or better still, just get a water cooled horizontal Diesel in the first place.

I actually just picked up a r170f, pretty awsome little engine, but on this side of the pond, parts are not as easy to get compared to the yanclones, and it's aircooled. 

I have an R165 and it's my favourite engine. that thing has more grunt than all my 5-6 HP rated engines and is just a fantastic little unit.
When I got it there were spare rings, bearings, gaskets and filters in the box.  I can get these easily as well and I think it would take a long time to wear them out anyway.


IF this conversion is something you just want to try, fair enough. I don't think you are going to get much help with the tech questions because I think you'll be pioneering such a setup.
I think I'd be doing the water jacket, adding a flywheel and leaving it there. swapping the parts out sounds like there could be a lot of pitfalls. maybe just try the water jacket?flywheels first, run the thing some hours and see what happens before you invest too much in the project.

[SteveU.]

Hello focodiesel
Welcome to the MicroCoGen.
On your projected useage(s) for your converted engines you are approching this 85% from the wrong direction.
Self made power and heat begins with the fuel source.
Self made power and heat ends with just how much of this "fuel" you can afford to supply on a continuing basis.
Example there are two active members here in MarcusB. and RobertB. who thier fuel souce is wastes automotive fluids like engine/transmission and power steering fluids and oils. So thier resonable engine chioce IS the big slow CS 6 hp Lister clone India engines. Big, very  low stressed, readily available cheap few parts allows them then to minimally pre-process their scrounged engine fuels. These are  big, slow, and designed for sub-standard (by todays standards) heavy fuel oils. Even able to lubricate well with very simple engine oils.
The SLOW rpm speed always means longer life is utter bogus B.S.  More important by far than the actual engine rpm is the actual piston speeds, lack of ALL internal abrasives, engine oil loadings and superior metallurgic matching.

Now for vegetable based engine fuels the big slow CS listeriods are kinnda sorta O.K. but the medium speed engine are better useable and many get better service with vegi oil fuels. Henry's recommened Kubota's 300 and 330 series; most of the water cooled ChangFa-iods and many others. This is glorts in use fuel and engines types.

Pump spec grade diesels then the more modern meduim to higher speed diesels will shine through with better fuel use efficiencies. Henry's and I think Derb's and mine and most others actual used fuels. Run these engines with good filtered and cooled spec grade lubricants and you will match and exceed the service hours of the older slower broader fuels tolorant tech engines.
And do this on the absolute least amout of spec grade pump petro fuel.

So man #1 what is your fuel type intent?

This along with later just how much engine fuel CAN YOU afford to purchase. beg, scrounge, grow and produce? on a continuous basis?? WILL drive your engine section.
Not just because container loads of cheap/available clone engines keep coming over from China  . . . . .  for now. Nothing last long. Do not lock your self in.

It is also NOT about how much power you desire. The above factors WILL force you to whittle down your power/heat consumer foot to fit your maintainable/affordable fuel/engine shoe.
Or even also NOT about how much engine waste heat you c-o-u-l-d use. The above factors in some climates some times of the year WILL you to have to supplement source fueling just for additional make up space heat. Same location, same climate some times of the years blowing off engine heats (wasting expensive fuel) from power generation just to get them out of the way from engine overheat damaging.

Always the Practical will rule over the Idealistic.
Regards
Steve Unruh - multi-times the acquirer of the wrong engine at the wrong time for the wrong use.

[focodiesel]

Focodiesel,
In your first post you lister flywheels. My guess is your talking about CS flywheels. The crank will not be able to support all that weight by itself safely. And then there is safe rim speed. It is not recommended and unsafe to exceed the safe rim speed.

Henry

Yes similar to cs flywheels but obviously smaller versions. Thanks for bringing up rim speed, if I do create them I will definitely engineer them and be very
cautious. Also thanks for bringing up critical engine speed, I assume that has to do with harmonics and resonance frequencies?

You also discuss crank rod angle being steep on the yanmars...So a longer connecting rod would be better have less force on the skirt/cylinder wall?

[focodiesel]

I'd suggest that -if- your power requirements are that low ( and I have read of very few people that are) then I would suggest you would be better off forgetting an engine and going with wind and or solar.  No fuel requirement, less maintenance and virtually never wears out.

I do plan on having solar. But why not have an generator too for backup and cloudy snowy days?

IF you are grid connected, I'd say an oversize engine is exactly what you want. Couple it up to a 3 phase induction motor and do a run back feeding to the grid. If your power consumption is so low you might only have to run the thing once a week to make back all your power. If you are off grid, a battery bank would be better than having to go start the engine every so often so the fridge and freezer can kick in or having the engine run 24/7. If you have a battery bank, again better to pump it up faster than slower.

I am grid connected, but the goal is to go off grid, I want nothing to do with back feeding my meter. The regulations are getting harder and harder, to me it is not worth it. Plus they will charge you all of the taxes, usage fees, demand side management... it is not long before a larger portion of the bill will be for things other than the electron work. I work for a power company so I can see all of this first hand. I understand the advantages, especially the near infinite load balancing, but at the end of the day it is an oligopoly and I wish to have off-grid peace of mind knowing I don't have to pay the ever inflating prices.

I think you will need to be doing it for the enjoyment because I can't possibly see you recouping your investment in time or money trying to sell people 2 Hp engines.
If you look here, the overwhelming theme is getting more power, not less. While your requirements might be very low, thats different to most people.
I would assess your market very carefully if you wish to make any sort of financial return.

Yes completely enjoyment, I am not thinking I will get rich quick off of this, more to hobbyists. I don't see why it is hard for you to see why I would spend so much time for a 2hp engine. Many members on board here spend countless hours on their 6hp cs listers, >20hp changfas, and other low power albiet reliable and efficient engines/alternators. Mobil bob has spent hundreds to thousands of hours tinkering with Leece Neville 110-555jho alternators that put out a max of what, 4kw in 48v form? I honestly don't think the overwhelming theme is getting more power, if that were the case people could buy a 200kw genset from military surplus for probably less than 20k. To me this stuff is about having fun, spending all of that time engineering and building and doing the poor mans r&d in the garage. A lot of what we do can't be justified financially if you start adding up labor costs. It's for the enjoyment factor.

If you want slow revs with any decent power output, you are going to have to go up on the capacity to get any worthwhile useable power.

displacement will be similar to the El300 and 165/170/175 changfas.

Exactly. Which is why you will have such low output.  When was the last time you saw a 1KW alternator?

Thousands of them on cars and trucks.

I have an R165 and it's my favourite engine. that thing has more grunt than all my 5-6 HP rated engines and is just a fantastic little unit.
When I got it there were spare rings, bearings, gaskets and filters in the box.  I can get these easily as well and I think it would take a long time to wear them out anyway.

yes mine came with rings, bearings, a filter, spare valves, honing compounds, and a whole slew of other cool stuff, and a great manual. 

IF this conversion is something you just want to try, fair enough. I don't think you are going to get much help with the tech questions because I think you'll be pioneering such a setup.
I think I'd be doing the water jacket, adding a flywheel and leaving it there. swapping the parts out sounds like there could be a lot of pitfalls. maybe just try the water jacket?flywheels first, run the thing some hours and see what happens before you invest too much in the project.

I will appreciate any and all help I can get. Thanks for you're comments.

-focodiesel

[focodiesel]

Hello focodiesel
Welcome to the MicroCoGen.
On your projected useage(s) for your converted engines you are approching this 85% from the wrong direction.
Self made power and heat begins with the fuel source.
Self made power and heat ends with just how much of this "fuel" you can afford to supply on a continuing basis.
Example there are two active members here in MarcusB. and RobertB. who thier fuel souce is wastes automotive fluids like engine/transmission and power steering fluids and oils. So thier resonable engine chioce IS the big slow CS 6 hp Lister clone India engines. Big, very  low stressed, readily available cheap few parts allows them then to minimally pre-process their scrounged engine fuels. These are  big, slow, and designed for sub-standard (by todays standards) heavy fuel oils. Even able to lubricate well with very simple engine oils.

yes a large portion of my fuel is wmo type fuels, I have had success with 50/50 in warm weather, and am working on fuel heating for cold weather and to try to run higher ratios, I currently have more wmo coming in than I can use. I would also like to experiment with adding woodgas to the intake, but that is far down the road.

The SLOW rpm speed always means longer life is utter bogus B.S.  More important by far than the actual engine rpm is the actual piston speeds, lack of ALL internal abrasives, engine oil loadings and superior metallurgic matching.

Utter bogus? the piston speeds are slower at lower rpm's, is this not one in the same? and wear increases with the square of the speed, I don't think that's bogus. 

[uber39]

Hello foco,
        Don't let everyones coments put you off, just pointing out the pitfalls , and there are many!!! As a suggestion read veggie's thread on a slow speed changfa , a very good read indeed if all you need is a modist output. All I'm after is about the same 1 - 1.5kw but constant and I'm curently trying a 165 same as glort.
        If you continue on this path you have my vote, as long as you keep us  updated with the good, bad and ugly.
        Lastly you are right, if we took our time into account $$$$$ just goto work and pay the power bill.
       Ian