ESE's works engine tuner

[husaberg]

One of the issues with fans is the problem with power going up exponentially with rev's. You don't need that much increase in airflow so the fan drive represents a loss up around max HP rev's.

The trick is to involve a torque limiting feature in the fan drive. Like a V belt that begins to slip over a certain torque.

I am pretty sure the electro and viscous coupling fan on the mazda/ford couriers do that.....


http://en.wikipedia.org/wiki/Electromagnetic_clutch

[WilDun]

Ducted fans soak up a lot of power and on a chainsaw it doesn't really matter but when trying to wring out a couple of horsepower on a bucket ......
I always thought (till now) that the original purpose of bucket racing was to keep things cheap and simple and give everyone a chance, but it's now gone way past that and we are into the realms of hi tech and expense.
Air cooling was used because all the little road bikes used for bucket racing were air cooled way back then, so these original barrels were kept on in the interest of simplicity in converting to a racer, but now, even that is obviously becoming increasingly more complicated to achieve comfortably than water cooling!
Ask anyone (who is able to manufacture a cylinder barrel) which is easier to do! - air or water cooled.
Guess all I'm saying is when you look at the lengths people will go to just to prove that it can be done, eg the posted photo of the bike - (think it might have been Frits who posted it) - the one with all those strange appendages sticking out of it. as opposed to a simple water jacket, radiator and tiny water pump which makes most sense?
- and no, I am actually very interested in all this experimental stuff, but an experimental design made simply to find a way past rules and restrictions? - no way!!
That just becomes a hobby on it's own, but I guess that's just how the (competitive) human brain works.

[Ocean1]

I am pretty sure the electro and viscous coupling fan on the mazda/ford couriers do that.....

Viscous clutches were common on a lot of American stuff, probably still are, but I don't think they were ever a particularly accurate torque control mechanism. I think most EM clutches are thermostatically switched, may be a useful secondary or control mechanism for a bucket but I'm not sure you'd want the fan kicking in just as you pulled out to pass that arsehole that'd been diligently blocking you for 5 laps coming onto the main straight.

I've seen two versions of flexible bladed fan, one where the cup on the blades simply flattened out as the pressure differential across them increased, which effectively produced a flatter flow curve, and another where centrifugal force did essentially the same thing, depowering the blades as rev's increased. I suspect either, or a mixture of both could map required air flow across the rev range quite accurately.

So could an electric fan with a variable speed drive, a few thermocouples and a basic PLC. A couple of standard bike radiator fans, one either side of the head/barrel and a bit of careful ducting might be enough.

[Ocean1]

- and no, I am actually very interested in all this experimental stuff, but an experimental design made simply to find a way past rules and restrictions? - no way!!

How many classes are there designed for technicians to excel, as opposed to riders?

[Yow Ling]

Viscous clutches were common on a lot of American stuff, probably still are, but I don't think they were ever a particularly accurate torque control mechanism. I think most EM clutches are thermostatically switched, may be a useful secondary or control mechanism for a bucket but I'm not sure you'd want the fan kicking in just as you pulled out to pass that arsehole that'd been diligently blocking you for 5 laps coming onto the main straight.

I've seen two versions of flexible bladed fan, one where the cup on the blades simply flattened out as the pressure differential across them increased, which effectively produced a flatter flow curve, and another where centrifugal force did essentially the same thing, depowering the blades as rev's increased. I suspect either, or a mixture of both could map required air flow across the rev range quite accurately.

So could an electric fan with a variable speed drive, a few thermocouples and a basic PLC. A couple of standard bike radiator fans, one either side of the head/barrel and a bit of careful ducting might be enough.

Strange really, a couple of the worlds authorities on small 2t engines categorically say , don't waste your time with air-cooled, thermally unstable blabla bla , the Aussies think they are a safety hazard , and you guys think by adding a fan you are going to come up with the next best thing. Its not like water cooled cylinders are made of gold or uranium or something rare.

[husaberg]

Strange really, a couple of the worlds authorities on small 2t engines categorically say , don't waste your time with air-cooled, thermally unstable blabla bla , the Aussies think they are a safety hazard , and you guys think by adding a fan you are going to come up with the next best thing. Its not like water cooled cylinders are made of gold or uranium or something rare.

I never said I was bright Mike...
20% leg up's in capacity are rare.........My own sudden interest in AC125's was from something Wob actually mentioned

[WilDun]

How many classes are there designed for technicians to excel, as opposed to riders?

Do you mean technicians or avid experimenters? I'm talking about the latter who are often self taught with maybe a trade background, but on the other hand there are the professionally trained people too like Dr. Gordon Blair etc. who made a huge contribution but didn't actually ever take part in the racing themselves.
The home experimenters are above being restricted by rules and regulations, classes etc. so long as they are working in their own environment, but sometimes they need to find someone to try out their creations on the track, I guess that's where they can become disillusioned ie. when they have to be hemmed in by restrictions and rules!
These are necessary of course. - Age old problem I guess and as you say, they don't have a class designed for them - but how can you design a class for pioneers?

This forum seems to work well without many restrictions, - sort of self moderates!

[Drew]

Viscous clutches were common on a lot of American stuff, probably still are, but I don't think they were ever a particularly accurate torque control mechanism. I think most EM clutches are thermostatically switched, may be a useful secondary or control mechanism for a bucket but I'm not sure you'd want the fan kicking in just as you pulled out to pass that arsehole that'd been diligently blocking you for 5 laps coming onto the main straight.

I've seen two versions of flexible bladed fan, one where the cup on the blades simply flattened out as the pressure differential across them increased, which effectively produced a flatter flow curve, and another where centrifugal force did essentially the same thing, depowering the blades as rev's increased. I suspect either, or a mixture of both could map required air flow across the rev range quite accurately.

So could an electric fan with a variable speed drive, a few thermocouples and a basic PLC. A couple of standard bike radiator fans, one either side of the head/barrel and a bit of careful ducting might be enough.

Fuck all that shit bro!

Lithium batteries weighing what they do, and electric motors driving the fans. Shit, in race terms that's free power!

[Yow Ling]

I never said I was bright Mike...
20% leg up's in capacity are rare.........My own sudden interest in AC125's was from something Wob actually mentioned

So it not just so you not need to destroke ?

[Drew]

So it not just so you not need to destroke ?

I figured that didn't get done much, do to the case volume not being that easy to reduce. Was I wrong?

[Ocean1]

Strange really, a couple of the worlds authorities on small 2t engines categorically say , don't waste your time with air-cooled, thermally unstable blabla bla , the Aussies think they are a safety hazard , and you guys think by adding a fan you are going to come up with the next best thing. Its not like water cooled cylinders are made of gold or uranium or something rare.

If I was going to waste some time it probably wouldn't be on a 125. I mean as much as I admire Smokey Unick's sentiment: "There's no substitute for cubic inches" he is demonstrably wrong. I was simply curious as to why the class seems to have ignored the whole fan cooled thing. If you're going to attempt to make a 25% capacity advantage work best it seems to me to be essential to minimise the disadvantage of the cooling system, no?

[husaberg]

So it not just so you not need to destroke ?

No (but it is part of the reason) I tried to find it Wob may not even know himself.......
if the new 107 rule goes through it is possible to do the 54.5. stroke by 50mm bore
Square would be better (I guess) under square does have a few pluses as well, according to some............

[Ocean1]

Fuck all that shit bro!

Lithium batteries weighing what they do, and electric motors driving the fans. Shit, in race terms that's free power!

It is. But it feels like cheating. And for the reason you've given I can't see stored energy remaining legal for long.

Besides, with less storage I could use regenerated brake energy to cool the engine.

In fact there's distinct possibilities in using a very large alternator and an even larger starter motor...

[TZ350]

One of the issues with fans is the problem with power going up exponentially with rev's. You don't need that much increase in airflow.

Electric fan, supplemented by natural air flow as the bike gets up to speed.

Lithium batteries weighing what they do, and electric motors driving the fans. Shit, in race terms that's free power!

Yep..... and they could be backed up by an on board generator, a generator does not draw any power from the engine until its required to produce current for the fan.

Could an electric fan with a variable speed drive, a few thermocouples and a basic PLC. A couple of standard bike radiator fans, one either side of the head/barrel and a bit of careful ducting might be enough.

Small DC motor speed control kits are cheap from Jaycar and you could use a range of thermal switches (also cheap) to turn the fan on and control its speed in switched steps.

Ducted fans soak up a lot of power.

True, but the power required can be pre stored in an accumulator.

I am actually very interested in all this experimental stuff, but an experimental design made simply to find a way past rules and restrictions? - no way!!

Making power makes heat, to make more power you have to get rid of more heat, finding ways past inherent restrictions is part of the challenge, if thats not your thing, then there is always the standard production classes like Super Bikes and F1, F2 etc.

I like riding my bike to see how the ideas work out but sometimes its nice to see how it could go with someone really good at riding on it.

Strange really, a couple of the worlds authorities on small 2t engines categorically say , don't waste your time with air-cooled, thermally unstable blabla bla,

World authorities say that about drinking and sin too, but it still has a fascination for me.

Its not like water cooled cylinders are made of gold or uranium or something rare.

But they are only a 100cc and this is a game where size can matter.

destroke ?

I figured that didn't get done much, due to the case volume not being that easy to reduce.

As the crankcase volume is a great place to store fresh mixture before its sucked up into the cylinder by the wave action of the pipe, the relative increase in volume by de stroking a 125-150 to a 100 could be beneficial.

[WilDun]

finding ways past inherent restrictions is part of the challenge, if thats not your thing, then there is always the standard production classes like Super Bikes and F1, F2 etc.

I like riding my bike to see how the ideas work out but sometimes its nice to see how it could go with someone really good at riding on it.

World authorities say that about drinking and sin too, but it still has a fascination for me.

I don't think I'll be riding any bike in the foreseeable future unless miracles do happen

Like I said humans often do things more for the challenge than for any practical reason and taking on that challenge really becomes the actual hobby, but that's ok.

Sin is probably a bit of a bitch to define - much like the restrictions we get imposed over fuels etc.etc. - nobody can decide exactly what should or what shouldn't be done and the fascination is really only to see how far we can go!