Pseudo Water Cooled Blaster

[deeeebeeeeee]

There has been more than once that i wished I could have a little extra cooling, at the top of a long and technical (if not particularly steep) hill, or when trail conditions or following a group cause you to spend alot of time under load at that one throttle position you know isn't quite as rich as everywhere else or maybe even after that wide open hail Mary run across the field, then immediately back onto a slow downhill section. Etc, etc, etc. It is just the nature of an air cooled 2-stroke, even when jetted properly it will get heat soaked, in some conditions. Even though if you are jetted properly there is little to no chance of burning it down under most riding conditions.
But you can quite easily get it hot enough to heat the incoming air charge enough to loose a good bit of power up to 20% maybe.
.
One solution I have pondered would be to use the oil tank, a windshield washer pump, and nozzle or two, as well as a small button to activate it.
The hardest part would be getting 12v DC to run the Ww pump. The simplest fix would be to get a hobby grade lipo battert to power the ww pump.
The washer nozzles could be mounted on the front fender bracket and aimed to fan out and hit from top to bottom halfway between the center line of the engine and the tips of the fins on either side.
The reservoir would initially be filled with ice water, and should hold about the same as a normal ww tank, at full power you should be able to get 50 or more 10 to 15 second bursts, a potentiometer (volume knob) could be used to adjust the flow and to an extent the pattern of the nozzles.
It might be better to point the nozzles up a little and lower the power enough to where it lobs the water at the front of the motor, that way when you are at speed the airflow won't cause the coolant to overshoot.
In addition to the manual button, you could also install a throttle switch that would activate a low power spray at WOT.

My greatest concern would be the effects of spraying, cool or cold water on a hot motor, but plenty of people hit water holes with a really hot motor and never think twice, I don't really think it will hurt anything. It will mostly just cool down the fins and possibly the front of the case and around the exhaust header.
The cooler fins, lower temp around the exhaust outlet, and slightly reduced crankcase temp. should all work to reduce excessive power robbing heating of the fuel charge.

Needed
Winshield washer pump (preferably one that has a barbed inlet)
Washer fluid hose and nozzles
3s lipo (1800-3000mah)
14-18 guage wire and intermittent switch ( preferably on that can be mounted in kill swit h housing or nearby
2 hose clamps and some thin stiff steel (a brace for the back of a car stereo works) to mount nozzlss.
Various wiring tools.

I will need to male a trip to the wreckers and get a Winshield washer system off of if. Wire and hose isn't a problem, I am not sure on the switch might use a small micro switch mounted under the kill/light switch with a tang that i can press with my left thumb. It would have to be at least as effective as the aluminum air deflectors and no heavier.

Might need refilled if used to often, the real deal would be rwo high pressure mist bars fogging the entire top/front of the engine based on cylinder head temp possibly even the temp measured at one of the base studs, delayed reaction maybe but with an manual switch as well.

 

[jvb]

There has been more than once that i wished I could have a little extra cooling, at the top of a long and technical (if not particularly steep) hill, or when trail conditions or following a group cause you to spend alot of time under load at that one throttle position you know isn't quite as rich as everywhere else or maybe even after that wide open hail Mary run across the field, then immediately back onto a slow downhill section. Etc, etc, etc. It is just the nature of an air cooled 2-stroke, even when jetted properly it will get heat soaked, in some conditions. Even though if you are jetted properly there is little to no chance of burning it down under most riding conditions.
But you can quite easily get it hot enough to heat the incoming air charge enough to loose a good bit of power up to 20% maybe.
.
One solution I have pondered would be to use the oil tank, a windshield washer pump, and nozzle or two, as well as a small button to activate it.
The hardest part would be getting 12v DC to run the Ww pump. The simplest fix would be to get a hobby grade lipo battert to power the ww pump.
The washer nozzles could be mounted on the front fender bracket and aimed to fan out and hit from top to bottom halfway between the center line of the engine and the tips of the fins on either side.
The reservoir would initially be filled with ice water, and should hold about the same as a normal ww tank, at full power you should be able to get 50 or more 10 to 15 second bursts, a potentiometer (volume knob) could be used to adjust the flow and to an extent the pattern of the nozzles.
It might be better to point the nozzles up a little and lower the power enough to where it lobs the water at the front of the motor, that way when you are at speed the airflow won't cause the coolant to overshoot.
In addition to the manual button, you could also install a throttle switch that would activate a low power spray at WOT.

My greatest concern would be the effects of spraying, cool or cold water on a hot motor, but plenty of people hit water holes with a really hot motor and never think twice, I don't really think it will hurt anything. It will mostly just cool down the fins and possibly the front of the case and around the exhaust header.
The cooler fins, lower temp around the exhaust outlet, and slightly reduced crankcase temp. should all work to reduce excessive power robbing heating of the fuel charge.

Needed
Winshield washer pump (preferably one that has a barbed inlet)
Washer fluid hose and nozzles
3s lipo (1800-3000mah)
14-18 guage wire and intermittent switch ( preferably on that can be mounted in kill swit h housing or nearby
2 hose clamps and some thin stiff steel (a brace for the back of a car stereo works) to mount nozzlss.
Various wiring tools.

I will need to male a trip to the wreckers and get a Winshield washer system off of if. Wire and hose isn't a problem, I am not sure on the switch might use a small micro switch mounted under the kill/light switch with a tang that i can press with my left thumb. It would have to be at least as effective as the aluminum air deflectors and no heavier.

Might need refilled if used to often, the real deal would be rwo high pressure mist bars fogging the entire top/front of the engine based on cylinder head temp possibly even the temp measured at one of the base studs, delayed reaction maybe but with an manual switch as well.

Just a thought,Why not use a Nos (or other brand) intercooler fogger system
mount the spray bar in front of the cylinder, and you have instant arctic conditions. lol
I would insulate the header section of the pipe! (Or else, there's a significant power loss)

Sneaky pete system above, nice small bottle...

 

[Blaaster]

Mmmmmm, the reason that I use a 25:1 mix of Castor oil.

 

[Jeff Bennett]

I thought I read somewhere that they did or could make the blaster watercooled with banshee parts or something like that. I wouldn't know how but seems like I read that, somewhere

 

[jvb]

I thought I read somewhere that they did or could make the blaster watercooled with banshee parts or something like that. I wouldn't know how but seems like I read that, somewhere

To make a Blaster water cooled isn't a problem, because the engine casings are based on a watercooled model: Dt200r so waterpump , jug are interchangeable

 

[deeeebeeeeee]

That would certainly work, there Is a ton of ways to do it. Even in near stock form I can notice a difference from riding my test path when the motor has just got good and warm, and 20-30 mins of low speed wheelie practice later when the from of the case has gotten a little hot to the touch. I guess this is normal as I didn't see any signs of blow by when I pulled the piston.

Anyhow if you were able to protect the air intake from the cooling charge, then you could use CO2 which is less expensive than N2O.
On the other hand if you fog with NOS the the motor will be gulping up, super cooled NOS laden air. Which would be a good excuse to add an adjustable power jet.

But back to the water cooling, it would cost little to nothing (I already have the battery, wire, switches,hose etc) as I only need to get a the pump and jet nozzles.
I think it might be better to make a custom bent spray bar of sorts with a hole or two drilled to spray across each fin on both sides.

Anyhow I got a motor to build before I can worry about not loosing a couple horse when it's hot, it would make more sense to cut a little more power into the cylinder while it's apart.

 

[pudvah]

Seems unnecessary though no?? I mean I've ridden my blaster for hours straight in upper 80 degree weather and if you were to touch the motor you for sure would get a serious burn but I never noticed a loss in power. I believe as long as you're leak free and jetted properly with a quality oil you shouldn't have to worry about over heating at all.

 

[deeeebeeeeee]

To make a Blaster water cooled isn't a problem, because the engine casings are based on a watercooled model: Dt200r so waterpump , jug are interchangeable

The problem with the DT200 setup is you have to order the oem parts new from canada, where there was a very limited release and hardly any to be had, Or you have to ship a donor motor or bike from overseas, where some countries still have quite a few laying around.
The go dt200 water cooled, you need from a donor bike jug, head, waterpump, radiator, cdi/control box, power valve servo, stator and regulator/rectifier (to get enough DC power.) , a spare wire or two.

Is it worth it, we it makes 30 reliable cool smooth power valve controlled hosres, is comparably immune to heat soak.

Would I go DT200 versus a rechambered, bored and ported stocker with bolt-ons? Probably not, for around $300 or so dollars over a standard top end job I can get a rechambered head, and port job, designed for whatever purpose, rpm range, and personality I desire. If you already have a pipe and carb to at least somewhat match the desired range.

Would I go DT200 versus a full Big bore build, with ported cylinder or re-sleeve and porting, carb and pipe, etc.,etc.
I don't race I ride for fun and the power valve is going to give me power and efficiency from bottom to top that is unmatched by anything without a power valve.
For me the attraction of the DT200 is nearly double the horsepower with the same or better reliability.
With high power porting and especially in air cooled engines, maintenance costs go up with the power. 20 hours on $100 piston, $30 in gaskets and materials and a bore job every other piston is what it takes to keep a high hp Blaster motor together.

Some claim with a forged piston rings at 20hrs. and piston at 40 hrs is the way to go
With a moderate trail port, a forged piston, and proper care (gentle warm up cycles, no lean spots in jetting, etc), it is said you can go like around 30-35 hours re-ring and go another 30-30-35 hours, before boring and getting a new piston.
Can it be done SAFELY? Only the specs at the 30-35 hour teardown can indicate the sanity of pushing further, but if there is no signs of scuffing and wear is at or below halfway between new and service, chances are you can get by with it. But you will be on your own. No engine builder on the planet is likely to reccomend or allow a piston with 30+hrs go back in for another round.

I have seen first hand what a cast piston will do if slapped around enough, a forge piston on the other hand fails in a much less catsstrophic, might even limp it home manner (so I am told).
Cylinder damage is still a concern, but a forged piston is not going to shatter and blow chunks of aluminum throughout the motor to be ground up by the crankshaft, piston ports, and bearings, and basically destroy top and bottom.

 

[Blaaster]

Forged Pistons do drop skirts and when they do they usually punch a much bigger hole in the crankcase than a cast one.

The solution to keep a hot engine from destroying itself is to use an oil with the greatest film strength that you can, and do not skimp on it.

 

[deeeebeeeeee]

That is interesting it was my undrstanding that a forged piston tended to flex and bend when over stressed mostly leading to hitting against the cylinder wall or the rod, and even when bend and slammed up against the rod wasn't likely to shatter kinda like an aluminum can, it will bend and flex many times before it starts to tear. Whereas a cast piston is more brittle and will shatter, more like glass, then continue to break into smaller bits as it gets smashed inbetween parts.

I can see where a seperated skirt of a forged piston would blow a huge hole in the case, but was under the impression that a forged piston is much more likely to show signs of damage and probable failure, unlike a cast piston which runs great, and give good compression right up until it suddenly shatters and slings chunks everywhere.

What would cause the skirt to break off of a forged piston, without first deforming noticably.