ESE's works engine tuner

[TZ350]

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Water cool the head, you know you want to. Don't worry about the barrell. The head is where most of the fire happens and the piston and barrell have the benefit of nice cold mixture swirling around and through them.

Water cool the head, yes I want to, but not allowed! 125 2 stroke! maybe a rule change to allow the old school 2 strokes to keep up with the new fangled FXR's!!!

Got to keep it fair you know.

[bucketracer]

My TF100's coming along fine, sounds like a water cooled head could be in order. Sent some money to some Dutch guys and they sent back detailed plans for pipe, cylinder, and head, 14,000rpm 32hp, total loss, programable ignition and hand made gears. These are the guys that convert 50cc Kreidlers to rotary valve and clock over the ton on them.

[speedpro]

Pity about the cranks and clutches

[gav]

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My TF100's coming along fine, sounds like a water cooled head could be in order. Sent some money to some Dutch guys and they sent back detailed plans for pipe, cylinder, and head, 14,000rpm 32hp, total loss, programable ignition and hand made gears. These are the guys that convert 50cc Kreidlers to rotary valve and clock over the ton on them.

So they are competition parts then? Illegal?

[bucketracer]

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Pity about the cranks and clutches

What!!!! Bugger. do you know something?

[bucketracer]

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So they are competition parts then? Illegal?

No No they just work out a plan based on their experiance, you have to hand make the bits yourself. The final result depends on your own efforts.

[diesel pig]

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The final result depends on your own efforts

F@&king A brother!

[Buckets4Me]

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So they are competition parts then? Illegal?

everything is a dam competitive part
you race your's dont you

but these are hand made
dont you like that cool

so we have the Dutch entering this now
and some Asian dude building engines
next we will hear that you guys are sending your engines off to be built by others

[TZ350]

.

Striped the engine, everything looks in great condition. Right sort of color on the top and underside of the piston. Perfect wash marks in the combustion chamber showing the transfer streams are evenly matched. Good plug color and dry exhaust. Clutch in good condition in spite of the hiding I gave it. Dam those GP125's are good.

Wrote up the log book and made plans for next year.

Performance wise, the lack of effective cooling of the Cylinder and Head is the limiting issue with air cooled motors.

Some Temperatures

Exhaust Gas Temperature:- 1000F, 540C to 1200F, 650C

Air Cooled Head:- 350F, 175C to 375F, 190C

Water Cooled Head:- 180 to 200F, 80C to 95C

Water cooled heads/motors run 100C cooler more or less than air cooled.

The big performance enhancement this year will be to try and find more effective ways of controlling the head temperature.

It's all about cooling fin surface area, thermal transfer to the air, air flow and heat input into the cylinder/head.

Some options I can think off:-

Ducting of air flow.
Detonation control.
Ignition control.
Ceramic coatings
Water injection.
Increased cooling fin area.
Variable forced air cooling.

I can see the real issue is getting the heat away from the immediate combustion chamber area. Which is what, water cooling is so good at. Air cooled motors have a long thermal path from the combustion chamber roof to the cooling fin tips.

I would love to hear of other options and what others have done/tried.

.

[speedpro]

I have done myself or helped someone else to:
Add fin extensions on a AC50 head, they helped a bit.
Watercooled an AC50 barrell, helped a lot.
Added fin extensions on the head and barrell and ducted air around the engine on a Honda XL125S, possibly some help.
Big air scoop /shroud on a AC50, helped a fair bit but not as much as watercooling.
Built a 100cc engine using a watercooled barrell, disappointing but very consistent. It didn't fade with heat.
Had a sidecar with a MB100 with a watercooled barrell, Had problems with pistons but power was consistent. Added watrcooling to head and piston problems went away.(when I remembered to turn on the electric water pump)

[TZ350]

Thanks speedpro for the background. My problem is power fade, from your information it looks like I need to find a way to improve cooling the head. I am looking at using some CPU heat sinks and cooling fans.

I have done some research (of course) and that increasing the velocity of the cooling medium, increases the scrubbing action and transfers heat better. With low velocity's boundary layers build up blanketing the radiating surface from the cooling medium. Pretty easy to imagine/see how this could happen to an air cooled motor at low speed.

All this pretty much fits with what you have told me before. I am hoping the controlled airflow/scrubbing action of the CPU heat sink/fans will help. Good thing is that the energy needed for the extra cooling can be stored in battery's before a race.

[speedpro]

As you have said earlier, the problem is the heat getting into the fins. I've thought about a waterspray system but that "might" be considered watercooling though not in the typical sense. I don't think you'd need too much water as long as it was atomised before getting to the fins. Bit like the intercooler sprays on Subarus though even they don't atomise efficiently I think. You need to effectively wet the fins with the minimum amount of water.
A possibility would be an electric fuel pump for a bit of pressure and some very small jets to atomise the spray. You could always spray methanol which would be fantastic, till it caught fire

[k14]

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As you have said earlier, the problem is the heat getting into the fins. I've thought about a waterspray system but that "might" be considered watercooling though not in the typical sense. I don't think you'd need too much water as long as it was atomised before getting to the fins. Bit like the intercooler sprays on Subarus though even they don't atomise efficiently I think. You need to effectively wet the fins with the minimum amount of water.
A possibility would be an electric fuel pump for a bit of pressure and some very small jets to atomise the spray. You could always spray methanol which would be fantastic, till it caught fire

And if you used methanol it wouldn't be water cooling would it

[TonyB]

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As you have said earlier, the problem is the heat getting into the fins. I've thought about a waterspray system but that "might" be considered watercooling though not in the typical sense. I don't think you'd need too much water as long as it was atomised before getting to the fins. Bit like the intercooler sprays on Subarus though even they don't atomise efficiently I think. You need to effectively wet the fins with the minimum amount of water.
A possibility would be an electric fuel pump for a bit of pressure and some very small jets to atomise the spray. You could always spray methanol which would be fantastic, till it caught fire

Sounds like what you need is a small fogging unit. They use high pressure and special nozzles to create fog- you can get ultrasonic versions as well which use sound to do the same job. They are very effective at dropping air temperature (so long as the relative humidity isn't too high). Not sure if you could get a fogging unit small enough to run on a bucket though!

[speedpro]

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And if you used methanol it wouldn't be water cooling would it

It could end up being a pretty spectacular barbeque though.