Hi Yow Ling, I had a look at the video and ran a Goggle. It seems that the exhaust ejector is a noisy beast, not as quiet as I had expected. It was good to actually see one, thanks for the link.Originally Posted by Yow Ling
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Forum whore
Hi Yow Ling, I had a look at the video and ran a Goggle. It seems that the exhaust ejector is a noisy beast, not as quiet as I had expected. It was good to actually see one, thanks for the link.
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No8 Wire Extraordinaire
Great! - so every time you pass him or are passed by him it will be like skipping rope with the extension cord.
Don't you look at my accountant.
He's the only one I've got.
Forum whore
"Instructions are just the manufacturers opinion on how to install it" Tim Taylor of "Tool Time"
Saying what we think gives us a wider conversational range than saying what we know. - Cullen Hightower
Forum whore
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Thanks for the links to those fans. I am most taken with the $90 one, ouch.
Here's a pic of my head and a CPU fan/heat sink that I thought had possibilities. Was thinking of using 4 of these on the head with the idea that they switch on and off as the head heats or cools.
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Bucket Racer/Crasher
The more I think about it the more I think fans aren't the go, unless you have a LOT more surface area than a stock fin sort of setup. Of course then you wouldn't need a fan. The idea of using a stack of sheet copper to make fins seems the way to go, you'd just have to watch the weight.
In fact it appeals so much I might have a good look at it myself for the 100.
Forum whore
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Yes I am very taken with your idea of a stack of copper sheets bent into fins.
My original idea was to add fin area and thermostatically switched fans by attaching several CPU heat sinks but there is a problem with getting them close enough to the combustion chamber itself on an original head.
My next idea was to have a fan blow down through a duct directly onto the head. The duct would allow natural air flow over the head from the front and direct the fan down and slightly to the rear so it arguments the natural air flow.
I like your stack idea a lot and can see myself building several different versions to try incorporating all these ideas.
Not only do I want to improve the total cooling capability of the head I want to control the cooling so the system can maintain a steady combustion chamber temperature like you get with water cooling.
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Forum whore
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Thomas with the F4 GP 3rd place cup and other Team ESE trophies. He was very pleased that his tuning work has performed so well.
Thomas is back onto the ignition. He has set the flywheel at the standard ignition point and is marking the position for the new ignition trigger button.
He has glued (Devcon) and screwed a metal trigger button on the flywheel.
Here he has the pickup that he salvaged from a cars distributor. Its like a Suzuki RGV pickup, it has a coil around some magnetic (nuts and screws stick to it) laminations.
The pickup is mounted on a sloted base so it has some adjustment.
Its adjusted so there is a 10-12 thou gap between the pickup laminations and the trigger button.
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No8 Wire Extraordinaire
Don't even begin to worry yourself with over cooling the head or barrel. Depending on how & where you measure water temp is best for power at ~ 55 deg C, although probably best for wear, fuel economy & anti-seizing at 70 deg. Pointless trying to overcomplicate the matter with cctry that will only be used first time through the gears.
Hmm, unbalanced weight on the outside of a hot vibrating piece of metal at 11,000 rpm. That might stay on.
Don't you look at my accountant.
He's the only one I've got.
Obey the hosebeast
Peltier modules can be found in some of the small 12V fridges sold at hardware shops, the 6 pack sized models: http://www.trademe.co.nz/Trade-Me-Mo...-197443299.htm
Forum whore
It was screwed and glued, but a part of me shares your doubts. If it cuts loose it could be like a ferrite up me trousers.
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Forum whore
It looks like the mish is going to be to build the biggest fatist head possible.
Standard GP125's have an asbestos? like head gasket, is this deliberate? are they trying to keep the heat of the barrel away from the head?
My current air cooled head has metal to metal contact with the barrel.
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No8 Wire Extraordinaire
It isn't asbestos it will be normal suzi composite gasket. Never had probs with metal to Metal with MB. Actually encouraged it as I had a thermosyphon head on my 50. Whether you want to get the cases any hotter is a question.
Don't you look at my accountant.
He's the only one I've got.
Forum whore
F5 is the main source of heat from the combustion chamber or the exhaust port tract?
Not had to realy think about this before but:-
Does heat flow from the cylinder into the head or the head to cylinder?
The head is the main heat source right?
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Forum whore
Not really fair to blame dave for that !
No8 Wire Extraordinaire
Story of my life.
The combustion chamber is as you say is the source of heat. As Boyle's law implies (indirectly) the volume is decreased as the temperature is raised substantially, both increasing pressure (there is no 'explosion' of gas as common myth, it is burnt to increase temperature). Which forces the piston down reducing pressure, but that increased temperature still has to go somewhere.
That corresponds to the head & piston, followed then by the barrel & the gas escapes somewhat cooler out the exhaust port. If it was a 4 stroke the valves cop it. Fourstroke exhausts run hotter than 2 strokes & I always believed that this is because the gasses escape more directly from the head rather than half way down the barrel (at lower pressure through a bigger hole). This probably accounts for some of the higher BMEP of a 4 stroke (aside from purity of charge of course) & why 2 strokes really favour being water cooled. Ideally the cases which are a pump would be cool to make for a denser mixture.
Erm where was I?
Oh yeah so I think all the parts are trying to shed heat, head especially of most benefit, but the piston is shedding heat on the bore through the rings & contact & proximity to the head in squish area, but if it heats too much it has to affect that charge in the cases. Also piston life seems much happier with a controlled barrel.
Don't you look at my accountant.
He's the only one I've got.
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