the HEADSMESS thread :o

THE WORLDS FIRST EXCLUSIVE EXPOSE! water cooling :)

firstly, i started up, idled for a few minutes, and didnt stop to check the excessive noise from the gears.

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suddenly bits went flying!


anyway. my exclusive. my piece de resistance :)

(brace yourselves)


THE WORLDS FIRST WATER COOLED MOTORISED BICYCLE :)

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note the use of the ngk b6Es cus i needed the 19mm thread and it was handy :)

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yep. thats a radiator :)


so. initial tests, at idle was, easy starting, and currently its thermosyphoning for circulation. a pump is in the works as we speak!

the blip up the road showed excellent bottom end power, with only a slight raspiness due to a slightly rich mixture still. still revs out nice but :)

the thermosyphon effect cant quite keep up with the demands of flow required at over half throttle. steam pressure popped my hose off. someone had to pedal 2km home :(

ive just clamped the hoses, so ill give it another go in a minute. if it lasts 5km i might keep riding to the radiator shop and try finding a standard cap fitting so i can fill it, blow off excess pressure, and have an overflow tank... otherwise i give up for a while and do something productive.


chose to avoid any squish band effect, just a hemispherical chamber, about 38 across by 8 deep. havent measured capacity yet. seems to work very well though.
 
lol. i went for an extended blat. clamping the hoses does help circulation. no sign of self ignition at idle until after a good KM at WOT. can see the steam bubbling up to radiator... return hose stays cold in comparison. definitely working.


next. pump and real radiator hoses.

oh, and a clean up. the place is a mess.



i just got a quote back from one laser cutters for my tuned pipes. at 200 for all the sections, 150 if i get 20 sets made, i can see why everyone says those guys are rip off artists. theres plenty others to try but!
 
You may be able to do without a pump if you make the head inlet connection on the low front side of the head, and the outlet on the high rear side of the head (although more ideal would be to turn the cylinder around so that the high end is also the hot exhaust side).
Years ago I made a solar water heater out of a salvaged water heater tank (inclined 20 degrees) with its inlet and outlet going to a homemade solar heat collector. no pump and it worked perfectly. hot water rises so that you can establish a natural circulation w/o a pump.
in your case the water heated in the head will rise to the outlet tube, and the inlet tube will receive cooler water to replace it (from the radiator).
 
yeah, i was contemplating sticking one of the fittings from the top just to sort of assist any convection, but obviously didnt. getting too close to the head bolts. just stuck the hoses to the back for now cus theres a small bridge between the hoses. meaning thats potentially the hottest spot. more than likely its less than a degree difference, so ill spin it around later on when i go to see how the chamber/pistons looking.


also contemplated hoses on either side but ensuring complete circulation made me go for being on the same side. one port, with two channels back into one port, you cant be positive water is flowing through both sides. and if one side ever gets a steam bubble, it will "lock". that side will get hotter and hotter, head will warp, etc etc etc.


nah, a pump isnt terribly hard. use a magnet, mount it down in the magneto case, and the magneto should drive it. saves needing seals then. doesnt need much flow/pressure, just a little bit more than the thermosiphon can achieve.


or get really dodgy for five minutes and use a fuel pump tapped into the crankscase... saves machining anything :) be fine with water.

the more height difference the more effective a thermosiphon is. this is almost on level :(
 
the thermo siphon idea has got to go.

i fiddled today. popped head off.

combustion chamber was nice. not black, not sooty. the oil wiped off leaving a minor stain.

so hooked up some 100psi hose. not heat rated so i expected failure before that...

once again, nice long idle, just checking.

oh, also fitted an elbow to the "hot" hose so it points up.

first signs were promising. went for a ride. 14km later, perfect. the hoses were nice and firm with pressure, and there was no sign of leaking, or the steam bubbles from the outlet on extended blats.

heat transfer from the radiator is stunning. the water is lukewarm coming out the bottom. need a thermometer. but head remains touchable for ten seconds...i got thick skin.

now the strange thing, this is what popped the lousy low pressure line.

i stopped at the shops for a coffee. 10-15 mins.

you would assume the thermosiphon to still be circulating when its cooling down, yes?

start up, go easy for the first km.

full throttle, and a few km later, pop. there goes the "cold" hose, in exactly the same place as the last one.

the head seems to get a lock in it. cant explain why. it just does, and once the steam pocket forms, it just blows the water back both ways.


conclusion? i need a pump. theres no way around it.

otherwise, running superb. the fairly high compression is giving it a nice kick, and taken most of the mid end nasties out of this pipe. and when it really starts winding out, oh my...

i didnt like this pipe too much. now its growing on me.

oh well! drawing board.
 
gaming computer. suits a standard pc fan.

visited a mate today. guy that first got me on a lathe and welding and stuff.

called me an idiot :giggle:

"a thermo siphon needs to be vented."


so its now simplicity itself.


a T piece has sorted it.

and soon, just a lil overflow tank.

take it for a 5 litre ride tomsa :)
 
filthy muck!

it rained today. there was little riding time.


so i put my latest pipe together.

firstly, whilst making the header connection, i just HAD TO take it for an unmuffled run, see how it goes with no exhaust at all.

i was pretty impressed :) this head is doing a lot more for increasing power than the dodgy standard one. then again, it may have been an inconclusive test cus the header is slightly tapered too. not a true straight parallel stub exhaust. but, wow. it pulled up the local hill almost as well as when piped. almost. it did tend to fourstroke at certain points then, weee, off it went again :)

i also had to take a few pics...


:giggle:

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a view inside the exhaust port...whilst idling :) not too good for the lens, apparently. all oily now :( it maynt be too clear, but notice that i port match my headers and shape the pipe to suit. pedantic fellas may like to use a dremel and take out the slight differences due to casting...


um, a pipe on a bench...

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a pipe on a bike...

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and, lastly...nice narrow profile. while they dont get hot enough to burn legs anyway, the tighter the better, me thinks :)
vertically, its in line with the clutch cover (when the things held in place and not just sitting like it is here...)

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just attach a stinger and some header springs, and off she goes :)


this one still is not perfect.

the shapes JUST about right, but i accidently based it on 24mm header pipe instead of the true 22mm. meaning that its not QUITE right still.

i definitely have the basic layout sorted now. i can make a paper template up in an hour or two, the metal takes a day still cus im hand cutting still.


anyway, two stage taper, fairly low taper, spread the band out a bit and reduce the peakiness at the designed rpm.


8000 rpm.


think it worked in at around 760mm total, from 24 to 56mm over 470mm back to 12mm on the sting.


testers tomsa!
 
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