Water cooled?
- Thread starter Blasterhart43
- Start date
I did one of these swaps. Will be doing another in the future.....
http://www.blasterforum.com/engine-mods-swaps-129/dt200-motor-swap-pics-43770/
http://www.blasterforum.com/full-rebuilds-128/dt-parts-blaster-build-46409/
http://www.blasterforum.com/engine-mods-swaps-129/dt200-motor-swap-pics-43770/
http://www.blasterforum.com/full-rebuilds-128/dt-parts-blaster-build-46409/
Porting the air cooled blaster cylinder and re-chambering the head will surpass the
DT200's power output.
The Blaster is 17hp and the DT200 about double that at 32hp.
As Joe says, porting the air cooled blaster cylinder and re-chambering the head will surpass the DT200. The stock DT200 is a bit of a screamer and tends to spin more than grab and run. Read the comparison link in my signature.
Once we get the details ironed out with the aircooled cylinder, we will be able to apply the lessons learned to a DT200 cylinder, which has a powervalve and water cooling. So far we are finding the cylinder head and the intake ports have a lot of improvements possible.
As Joe says, porting the air cooled blaster cylinder and re-chambering the head will surpass the DT200. The stock DT200 is a bit of a screamer and tends to spin more than grab and run. Read the comparison link in my signature.
Once we get the details ironed out with the aircooled cylinder, we will be able to apply the lessons learned to a DT200 cylinder, which has a powervalve and water cooling. So far we are finding the cylinder head and the intake ports have a lot of improvements possible.
It really comes down to whether the DT200 top end has enough "meat" in it to improve a lot or not.
Everything else being perfectly equal, you can put out more power (on gasoline) with liquid cooling. The cylinder has a very thin aluminum layer around the iron sleeve with a liquid jacket around that. The heat generated during combustion is passed, either directly or through the piston, into the liquid to be carried off. A SUPER hot blaster engine (think fully built race spec in the desert) can get hot enough to begin disintegration if everything is not absolutely perfect while the liquid cooling gives you margin for error.
HOWEVER, there are limits. A stock blaster engine has enough aluminum around it to go hog wild as far as head design and port design. It MAY actually be that the DT200 top end is more limited in port layout and potential top end power because it's liquid cooled!
Everything else being perfectly equal, you can put out more power (on gasoline) with liquid cooling. The cylinder has a very thin aluminum layer around the iron sleeve with a liquid jacket around that. The heat generated during combustion is passed, either directly or through the piston, into the liquid to be carried off. A SUPER hot blaster engine (think fully built race spec in the desert) can get hot enough to begin disintegration if everything is not absolutely perfect while the liquid cooling gives you margin for error.
HOWEVER, there are limits. A stock blaster engine has enough aluminum around it to go hog wild as far as head design and port design. It MAY actually be that the DT200 top end is more limited in port layout and potential top end power because it's liquid cooled!
lets not forget the Power Valve and boost bottle ( I know I know boost bottles dont do anything8-|). Aswelll as the DT200 CDI which may or may not have a different timing setup (possibally for the PV???).
James brought up another fact i was thinking, Temp. i know the dt setup will take a main jet around 5 sizes smaller then the air cooled motor (with a pipe i ran a 240 main in mine). it would be cool to get our flar pics of the dt motor and see what temps it makes it too. A motor running within a cooler temp may help??
i never thought about the extra material that the aircooled would have but thats a good point aswell.
i plan to do a harness swap to get mine setup with a PV to see the difference. i know withoutt the servo and manually playin with the PV it made a HUGE difference in the output. Neat stuff
James brought up another fact i was thinking, Temp. i know the dt setup will take a main jet around 5 sizes smaller then the air cooled motor (with a pipe i ran a 240 main in mine). it would be cool to get our flar pics of the dt motor and see what temps it makes it too. A motor running within a cooler temp may help??
i never thought about the extra material that the aircooled would have but thats a good point aswell.
i plan to do a harness swap to get mine setup with a PV to see the difference. i know withoutt the servo and manually playin with the PV it made a HUGE difference in the output. Neat stuff
Yeah, playing with the FLIR camera I find the aircooled 2 and 4 stroke engines often max out the FLIR at 150c = 300f (reading over 400f on the plug sensor) where as the liquid cooled never run more than 110c = 230f or so. That alone would account for jetting differences. The aircooled is using fuel to cool the piston whereas the liquid is doing it in the liquid cooled.
The DT200 does have a different curve, we have posted it here before. It has more timing retard at high rpm to extent the peak rpm by pushing heat into the pipe. It also has more advance in the mid-range to fill that in a bit. Both engines have strong retard at kicking speeds to prevent kick-back. Other than that, the Blaster curve is essentially fixed flat.
I think you make a good point about aluminum thickness James, and that ultimately we will likely be drilling boyesen and 3rd exhaust ports, just not there yet. Don't know if the DT200 can handle that. It is certainly thicker than my KTMs are, and weigh more.
What a wonderful learning tool these Blasters are...
Steve
The DT200 does have a different curve, we have posted it here before. It has more timing retard at high rpm to extent the peak rpm by pushing heat into the pipe. It also has more advance in the mid-range to fill that in a bit. Both engines have strong retard at kicking speeds to prevent kick-back. Other than that, the Blaster curve is essentially fixed flat.
I think you make a good point about aluminum thickness James, and that ultimately we will likely be drilling boyesen and 3rd exhaust ports, just not there yet. Don't know if the DT200 can handle that. It is certainly thicker than my KTMs are, and weigh more.
What a wonderful learning tool these Blasters are...
Steve
Is a 92 wr200rd the same as a dt200 cause I
Was looking on Yamaha for dt parts and found the wr200
Was looking on Yamaha for dt parts and found the wr200
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