Water cooling the Bucket

[Sketchy_Racer]

Thought I would put pics up of the water cooled head I made for my H100 bucket motor.

The reason for the water cooling is to maintain my motors power as at the moment I start the race with good power but slowly lose it as the engine heats up beyond the optimum running temperature. I don't have easy access to ally welding so I decided to try make one out of fabricated alluminum. It worked reasonably well, and it seems to work effectively.

I started by grinding off all the fins off the head, then machining a shoulder for an outer ring to bolt up against and seal.
This posed the problem of exposing a couple of casting imperfections and the resulting holes. Never to fear the JB weld will fill them up.
I then made the outer ring which is what gives me my water capacity, I tried to keep this as a minimum inside the head as to much water capacity in the head will slow down my flow with the thermosyphon. Finally a top cap with water inlets and and outlets and we're ready to bolt together.

Mount the radiator at a level above the head. I was hoping to place the radiator on the frame somewhere but this proved to difficult due to the fact that it has to be above the head for thermosyphon to work. So it got mounted where the front number board would usually go and piping running through the chassis back to the head. It took a little bit of thought to prevent the pipes from binding when the steering turns but it worked out well in the end.

I love thermosyphon, not having a water pump is great as it removes another component that can fail. It's a very simple system, where the water in the head is heated, in which process the water density changes and become less and naturally the cooler water in the radiator wants to fall (much like hot air rises) and occupy the space of the of the less dense water which then creates a self regulating flow in the cooling system. It will take a little bit of time to set the system up to maintain the correct operating temperature of roughly 55 degrees.

It took me three evening in the shed to make this and I am looking forward to testing and setting it up on the track!

Anyway, here's the pics!

Cheers,

-Sketchy

[richban]

Thought I would put pics up of the water cooled head I made for my H100 bucket motor.

The reason for the water cooling is to maintain my motors power as at the moment I start the race with good power but slowly lose it as the engine heats up beyond the optimum running temperature. I don't have easy access to ally welding so I decided to try make one out of fabricated alluminum. It worked reasonably well, and it seems to work effectively.

I started by grinding off all the fins off the head, then machining a shoulder for an outer ring to bolt up against and seal.
This posed the problem of exposing a couple of casting imperfections and the resulting holes. Never to fear the JB weld will fill them up.
I then made the outer ring which is what gives me my water capacity, I tried to keep this as a minimum inside the head as to much water capacity in the head will slow down my flow with the thermosyphon. Finally a top cap with water inlets and and outlets and we're ready to bolt together.

Mount the radiator at a level above the head. I was hoping to place the radiator on the frame somewhere but this proved to difficult due to the fact that it has to be above the head for thermosyphon to work. So it got mounted where the front number board would usually go and piping running through the chassis back to the head. It took a little bit of thought to prevent the pipes from binding when the steering turns but it worked out well in the end.

I love thermosyphon, not having a water pump is great as it removes another component that can fail. It's a very simple system, where the water in the head is heated, in which process the water density changes and become less and naturally the cooler water in the radiator wants to fall (much like hot air rises) and occupy the space of the of the less dense water which then creates a self regulating flow in the cooling system. It will take a little bit of time to set the system up to maintain the correct operating temperature of roughly 55 degrees.

It took me three evening in the shed to make this and I am looking forward to testing and setting it up on the track!

Anyway, here's the pics!

Cheers,

-Sketchy

Nice work mate long time know race. Look forward to seeing you out on the track. Head looks cool.

[Sketchy_Racer]

Nice work mate long time know race. Look forward to seeing you out on the track. Head looks cool.

Tell me about it dude! I'm missin my bucket fix! Kaitoke is shut for two weeks as well which sucks!

[Rick 52]

Good work Will we see it at Taupo?? or Auckland 2hr hope so .

[richban]

Tell me about it dude! I'm missin my bucket fix! Kaitoke is shut for two weeks as well which sucks!

Well you will be pleased to know in an effort to beat your ass another engine is in the making. The stroker is in production. Duf duf wheelie duf duf gone.

[TZ350]

Its really great to see these hombuilt racers and the clever ideas............

[hmurphy]

What!? You don't need anymore power you cock! Oh wait, was supposed to think "he's a cock" and say "wow that's awesome Glen!". Haha Nah it's cool man, your bucket is wicked. I hope to have another squirt sometime soon. I'm a member of Kaitoke with a key now so lemme know when you are heading up there next, I'll come join.

[Henk]

looks cool. Dredges memory, max power 50 degrees, minimum seize 70 degrees, thermosyphon talk to Speedpro.

[Kickaha]

Looks way to tidy a job for a bucket compared to what I've seen in the past

What about doing the barrel as well?

[gatch]

Awesome work man. I'd love to take a closer look at some point..

[SS90]

Looks way to tidy a job for a bucket compared to what I've seen in the past

What about doing the barrel as well?

Na, not needed...causes more problems than it solves.... not the least of which is running too cold....ask Russell Bleach about that one.

[gatch]

Na, not needed...causes more problems than it solves.... not the least of which is running too cold....ask Russell Bleach about that one.

I reckon it's possible, if the water jacket was reasonably thin and you controlled the flow, you could tune it as you would tune any other system..

[SS90]

I reckon it's possible, if the water jacket was reasonably thin and you controlled the flow, you could tune it as you would tune any other system..

Sure, I had a 100cc Yamaha (actually, it was 102cc...shhhhh) that had (by someone else) been converted to a compete water cooled top end.

The guy I brought it off knew the history, and just how much effort had gone into it to make it run at the right temperature, and when I got it, the cooling system worked 100% , but only because others had worked at it.

The problem had been over cooling.... it's easy to see how that would happen.

It ran a mechanical pump, and that makes things a little more "hit and miss" when it comes to setting up the cooling system (particularly operating temperature), nowadays with the easily available electronic pumps, with adjustable flow rates etc, getting the flow right for the temp takes one or two meetings opposed to half a season or more.

I still think the gains are dubious in cooling the whole cylinder when dealing with non bridged ports etc (cooling the exhaust bridge is a massive worthwhile exercise, both in terms of power and reliability for example, and if you made your own cylinder, and where able to do that, then I would say it is worthwhile).

In my tuning circle, the consensus is to "save your self the effort", and just liquid cool the head.

Sketchyracer has outlined the advantages of thermosyphon, and for the sake of simplicity, I agree with his decision.

I believe if he had water cooled the cylinder and the head, perhaps the thermosyphon system would not work so efficiently (due to the higher volume of water), and require not only a bigger radiator , but possibly mounted 40cm higher than it already is to function.

[Kickaha]

Sure, I had a 100cc Yamaha (actually, it was 102cc...shhhhh) that had (by someone else) been converted to a compete water cooled top end.

What happened to that bike ? and I mean after I fucked it:shifty:

Diesel Pig tried thermosyphon on his GP/RG 100 hybrid but couldn't get the temperature down to what it should be, he ended up ditching it for a Davies Craig electric water pump

[SS90]

What happened to that bike ? and I mean after I fucked it:shifty:

Diesel Pig tried thermosyphon on his GP/RG 100 hybrid but couldn't get the temperature down to what it should be, he ended up ditching it for a Davies Craig electric water pump

So it was you! I thought it was Brian Hardaker!

The frame is gone, and I ended up giving the engine (after you mercilessly rung it's neck and ran the big end) to Russell Bleach ( who I got it off), I recon it is a piece of Bucket history, and the best place for it is Russels.

It's a cheater anyway, the wiseco piston made 102cc.

the key with thermosyphon is having a low amount of water, it improves efficiency.

[F5 Dave]

erm, the oversize capacity on 100s is 104cc & has been for as long as I can remember. Wiseco pistons have been legal for over 10 years (pistons free). So it was (is now) legal. Sorry.

I thermosyphoned my MB50 decades ago, was easy in that frame to run a rad above the head but below the steering. Still worked ok.

I made a later one but made the mistake of not using enough material. Too thin means no thermal mass = warp.

[jasonu]

Looks like you made a very nice job. About the only thing I question is the lack of a h2o pump. You can get very nice (and small) inline electric pumps and compact rechargeable batteries that do a good job.

[Kickaha]

Looks like you made a very nice job. About the only thing I question is the lack of a h2o pump.

If thermosyphon works correctly he wont need one

[jasonu]

If thermosyphon works correctly he wont need one

Your statement is correct 'IF' it works...

[Sketchy_Racer]

It will, I will make it! I have a couple of different radiators to try if this one isn't sufficient.

[SS90]

I say go for it, it will work, it just takes a bit of time to set up.

Jasonu is right though, the modern water pumps are great.

[schrodingers cat]

Would it be possible to oil cool the head using engine/GBox oil? No need for a radiator then.
Nice consistent shifting them too

[gatch]

Would it be possible to oil cool the head using engine/GBox oil? No need for a radiator then.
Nice consistent shifting them too

Anything is possible. My guess is you might need a tougher oil pump and probably an oil cooler.

Though you could probably be clever and use a dry sump set up and use the oil tank as a heat exchanger ?

[Sketchy_Racer]

Anything is possible. My guess is you might need a tougher oil pump and probably an oil cooler.

Though you could probably be clever and use a dry sump set up and use the oil tank as a heat exchanger ?

haha how to make a simple job very difficult!

[Kickaha]

haha how to make a simple job very difficult!

He must be an engineer:shifty:

[TZ350]

He must be an engineer:shifty:

Or a Manager...........

[gatch]

haha how to make a simple job very difficult!

Piece of cake !

I'm not going to do it though, because um, I ahh, am too busy..

[SS90]

Would it be possible to oil cool the head using engine/GBox oil? No need for a radiator then.
Nice consistent shifting them too

Worked fine for Sukuki (albeit with an oil cooler) for 2 decades. The reliability of their SACS equipped bikes is still stuff of legends.

On two strokes though, it could be an issue, perhaps overheating the oil?, I know that on some prototype stuff, some gearbox oil cooled KTM kids biks had a problem of over cooling the oil....... unlikely if you didn't run a cooler.

It would be too hard to impliment..... although Suzuki RGV's, Yamaha TZR's and Cagiva Mito's all had pressure fed gear box oil, (all except the mito on cassette gear box's), it would really only be tangeable on a 4 stroke.

[speedpro]

I did a thermosyphon watercooled cylinder AC50 in the early '80s. The radiator was mounted behind the cylinder on top of the cases. It worked so well I had to tape off the whole radiator except for about 10mm. The radiator was a custom built one but only about the size of an RG50 one. When it rained I had to duct tape the whole radiator front and back.
I've just got the MB thermosyphon system working. You don't need any height difference between the radiator and the hot bit. As long as the heated water can flow up and into the radiator where it can cool and flow down and return to the hot bit. They can be mounted at the same height. Check the #6 thread for what I mean.

[Skunk]

They can be mounted at the same height. Check the #6 thread for what I mean.
He's young and didn't believe me... :laugh:

[TZ350]

I know its not Buckets but it is thermosyphon and cooling by latent heat of evaporation.

I remember the thermosyphon water cooled single cylinder engines that ran milking machines, water pumps and shearing sheds on remoter farms. Usually the radiator was just a 44 gal drum fill of water sitting on a stand next to the motor. As the water evaporated away, it was topped up.

Some engines used a different principal and relied on the latent heat of evaporation to directly cool the cylinder and had a water reservoir cast above the cylinder, which was kept topped up.

Two engines with water drums can be seen on the back of the trailer and one with a cast reservoir can be seen at the front right corner of the trailer.

[Sketchy_Racer]

So I fitted a temp gauge to the bike, got a slight problem though, it's obviously getting interference from the ignition because as soon as the bike is turning over, the display goes blank doh! but once the motor has stopped, it shows the temp. I took the bike for a quick test run after warming it up and I may have hit the jack pot as the temp seemed to stabalise at around 50 degrees, which is a little to cool, I will aim for 55 but better to run cold than run hot!

Can't wait to really put it to the test!

[hmurphy]

Wicked! How do you make it run a little hotter with a system like that? So you will make an appearance at the next buckets then?

[quallman1234]

Wicked! How do you make it run a little hotter with a system like that? So you will make an appearance at the next buckets then?

As dave said, you could tape up part of the radiator to reduce the amount of cooling fins exposed.

Pretty cool dude, did it pretty frecken quick too!

[F5 Dave]

That was Mike, but yeah common to tape. Was it a Daytona temp gauge? I had no end of problems with mine getting interference. I was going to run a thin coax wire & maybe some filtering but lost interest.

[quallman1234]

Perhaps reducing the diamater of the piping from the radiator to the head and back, could also reduce the amount of fluid being able to be flowed.

Anywho, doesn't seem too far off. A fair bit of hard riding should bring it up a couple of more degress.

[Ivan]

get a rg50 temp gfauge they were accurate as always at half on the gauge

[SS90]

That was Mike, but yeah common to tape. Was it a Daytona temp gauge? I had no end of problems with mine getting interference. I was going to run a thin coax wire & maybe some filtering but lost interest.

I have had the same problem with all the daytona stuff, (incl ex temp sensors, and rev counters), I wrapped the pick up lead on one with tin foil, then covered it in insulation tape, and it worked, dod the same for another and it made no difference.

Go figure.

[F5 Dave]

yeah a friend had the same gauge mounted on the same type of bike in the same place with the same ignition & the same plugcap & had no problem. I had one 2nd hand one, a new one & a replacement one give trouble. Maybe it knew he worked for the distributor at the time so gave no issue.

[Kickaha]

The Daytona gauges tend to have fairly flimsy wiring into the back of the unit, we always used to replace and resolder it when we ran them in the Karts