Forum whore
why not just get a really big aircooled head off say a MZ250 weld up the combustion chamber and machine one that suits your engine. i think you are really going to struggle with the fan thing . I was looking at a fan at work today that would probably do the job but it was 1.1KW 3 phase. Think how big the fan at the dyno is and thats just for short runs.
Forum whore
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Using a head like you suggest is a good idea. It would be interesting to test a fan cooled CPU heat sink. Any ideas how to conduct an experiment?
Thomas has found a piece of 1.2mm copper sheet at work and as I have a 12mm alloy spacer under the barrel he suggested replacing it with one made out of a stack of copper fins and a heat resistant block so that I wind up with some more finning for the barrel and a heat blocking spacer at the bottom so that the crank case runs cooler for a better incoming charge density.
As the clutch gets a real caning he also suggested an oil cooler for the gearbox like they have on auto trans gearboxes.
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Bucket Racer/Crasher
If F5 gets away without one you sure as hell don't need one.Originally Posted by TZ350
Bucket Racer/Crasher
Some sort of constant heat source applied to the combustion chamber or whole base of the cylinder head(s) and a fan blowing over the head. Measure the head temp. The better the fin system is at dissipating heat the lower the head temp will be. It'll be interesting to see what effect varying the air flow will have.
Forum whore
Your right, I can't claim to be making much more HP than him if any and he realy does cane that clutch, thats one real fast 50. How long does that engine last between rebores/overhauls?
bucket blingster
Probably easier just to move down to Christchurch, don't think anyone was too concerned about an overheating head at the last Battle of Buckets?However fitting heated handgrips might be worth considering?
Bucket Racer/Crasher
We could kill two birds with one stone. Convert to 100cc, watercool the motor, route the coolant through the handlebars.
bucket blingster
KA CHING!!!
Brilliant!
Forum whore
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Probably easier just to move down to Christchurch, don't think anyone was too concerned about an overheating head at the last Battle of Buckets?Bucketeers realy are clever people.I like the idea and if I crash will that make me a snow goose? Sorry F5.
Registered User
Has anyone one tried machining small horizontal fins on the sides of the vertical fins. More surface area without greatly increasing the cooling path.
Hardcore Biker
sound like you need a ballast resistor to stabilise voltage Maybe if something was set up to come on a a certain number of revs to burn off excess current
Forum whore
Thats very clever, hadn't thought of that, it's all about surface area, now your got me thinking.
Fair weather rider
I can see that us four strok boys are gonna have to do a lot of work to keep up with the sort of things your talking about on here.
Either that or we're gonna have to do a lot of talking to keep up with you guys........
Forum whore
start talking they are way ahead of you thereI can see that us four strok boys are gonna have to do a lot of work to keep up with the sort of things your talking about on here.
"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
Got the makings together for a new super Head.
Its going to be a very special head made from a large block of alloy, off cut of copper sheet and an extra heavy section of heat sink.
The plan is to sandwich the copper between the alloy block and heat sink for extra rapid heat dispersal to the outer parts of the heat sink.
The finished head will be about 4 times as heavy as the original GP125 head.
With all this alloy and copper, this has got to be the real deal, RIGHT. WRONG! Wrong! wrong! very very wrong as it turns out.
Another counter intuitive thing, bigger should have been better.
When Thomas saw what I was up too he nearly wet himself laughing.
Then he explained to me that Suzuki was not trying to save money by having a relatively small amount of alloy around the combustion chamber.
He said the Suzuki head is made thick enough for strength and for the combustion chamber shell to provide an adequate thermal path for the expected heat load. And thin enough so the thermal path to the root of the cooling fins is as short as possible.
Its for this reason that most air cooled 2 strokes of that era used ½ inch reach plugs and Ύ inch reach plugs were mostly used in the water cooled motors to allow more room for the water jacket.
If I was to make a head out of the block of alloy like I intended it would be able to absorb a terrific amount of heat energy but relatively too slowly to keep the combustion chamber cool.
There might be more fin area but the cooling fin tips would probably run cooler (cooler is less efficient at shedding heat) than the original Suzuki head. And the heat path would be to long and the combustion chamber would over heat (or at least be a lot hotter) even though there was more thermal capacity and fin area in the bigger head.
Its that the cooling bit will be to far away from the fire bit.
He suggested we continue to use ½ inch reach plugs and cut the alloy block down and mill steps in it so that cooling fins of copper (copper conducts heat away twice as fast as alloy) can be fastened to the alloy combustion chamber, shell as close as possible to the source of heat.
Even better would be to make a thin combustion chamber shell out of beryllium copper (for strength) and easy-flow copper cooling fins to it.
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