View Full Version : forced air into carb?!?!

07-03-2002, 08:08 PM
seen a guy with some radio shack fan small enough to fit the diameter of the air filter. the theory was to force cool air into the engine. it seems like a novel idea but since i hardly ever hear of anyone else doing it, there must be some drawback. i asked him about the performance and he said it ran better. but he could be pulling my leg because i didn't see him run it.

07-03-2002, 08:50 PM
More crap that ain't gunna work. Forced induction does NOT work, and will not work on these types of engines. Give it up people, it ain't gunna happen!

07-04-2002, 02:40 AM
Think of how hard and fast your exhaust is working at peak RPM... can his little fan match that?

Unless it can, it is giving him negative airflow compared to before.

The other little problem he might encounter is that unless his little fan can build up a couple of bar, he aint pressurising anything.

And the last, over-pressurising piston-ported 2-strokes is fairly pointless - all you are doing is blowing that charge out of the exhaust port.

07-04-2002, 05:41 PM
First off, the fan is irrelivant. The crank rotation is going to draw air in at a faster rate then the fan could even think of producing. Secondly, in conjuction to the first point, the fan is doing nothing while the crank port is closed, just waisting battery life, weight and cargo space. I'll bet you that that fan is actually restricting the air and causing him to run leaner, giving him the impression that he is increasing performance. The fan, depending on how is is mounted, will restrict the pressure flow that the crank case wants to provide to the piston because it is moving stangnet air, not pressurizing the air. If he claims to be pressurizing the air, how is doing it while the crankcase is shut, he would essentially be pressurizing the area between the crank intake and the fan and slowing the fan down, and/or burning the fan out and/or reciving blow by on the fan and forcing air out of the crank...therefor reducing the pressure and increasing the heat. This dude is full of ****. Increasing the crank pressure any more would throw the fuel into the piston chamber so fast and at such high velocity that the fuel would be forced out of the exhaust port, once again casing him to run leaner and destroying his motor....

Just my though, but what do i know.

07-04-2002, 07:56 PM
your response makes so much sense. cant wait til i see him so he can actually run it.

07-05-2002, 03:09 PM
Originally posted by TyceCCSU@aol.com
Just my though, but what do i know.

You got it covered, pretty much :)

and Thugg, tell him to disconnect the battery - I'lll bet he doesn't see any change in performance... the fan will spin and the leanness will continue to give hime good performance :)

07-05-2002, 05:03 PM
it was told earlier, that it could make your engine stall, cause of high preassure, under piston, which would make it impossible for piston to mov down,

07-05-2002, 10:21 PM
I read many reviews on this topic and this is what I came up with.

The fan would only be a drawback because Of these reasons.

1-At higher RPM the fan could restrict air flow.
2-The extra air would be forced out of the Exhaust.
3-The fan would cause the engine to run cooler and It would not reach the running tempture, you would have to run leaner and damage the engine.
4-The fan would be dead weight and drain the battery power.

I think that's it