Making third intake on 66cc.......................

Yes, but a piston ramp made at a very shallow angle (close to horizontal) has no affect on powerband. It is only done because pistons are more expendable than cylinders. You change the port timing by making a ramp in the piston and that way you can experience the effects of the porting change before raising the port the same amount and replacing the test piston.
If you make the ramps for the transfers at 40 degrees or more then it broadens the powerband by restricting the flow at low rpm, thus making like the transfer duration is smaller. At high rpm its like there's no restriction and the transfer duration is larger. I had a different theory of operation before which you can read on my web site but I found a flaw in its logic that only the new explanation corrects. I need to update that page and add graphics to fully explain. Number 101 on my list of gazillion things to do. But its really hard to explain although its clear in my head. Really a video is needed but I hate being photographed.
 
Jag, a video would be most appreciated. If you don't want to be photographed, you can video it from your prospective only using your hands and voice demonstrating how & what you are trying to show..
 
Well, got Arrow reed valve on...............Might be a bit smoother, but not as much torque as the extention!! It's pretty much the same as it was?!~ DARN.:(

Hey, but it looks like it would do something.......................?? Question is.............WHAT?

(I tried Jag, with extention mounted after reed........nothing, Speed carb ........nothing,CNS carb......nothing.


So, in order to get anything out of this reed, I do believe I'll need to port inside jug + drill out piston?!

IDEAS for immediate fix?

TY, Glen
 

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Reed valves work hand in hand with expansion chambers. Buy one and cut the baffle in half and weld in a 50mm (2") long metal cylinder to convert it from a pocket bile race pipe to a Grubee street pipe.
 
The Arrow reed valve is going to work well on a full tilt, heavily modified, high performance 2-stroke China Girl engine - perfect for racing, but not optimal for the street with conservative cylinder port timing and a non optimal exhaust system.

That's where the Rock Solid Reed valve is a better option, for many reasons as i have previously described.

I guess we all live and learn, sometimes going against advise and experience, but we still learn!
 
Thanks guys.....

Yeah, I was told so, but you have to start somewhere. Fabian, I just thought that the Arrow would be more compatible with the Grubee 66cc. See, like the 7.5" extention I've had on bike intake, vs a more compact reed like RS. Uno, thinking that the bigger area of the Arrow, would act better to enhance torque. WRONG huh..............

Well, this little venture cost me! (At this point)
 
The Arrow reed valve intake will still be useful if you decide to go motor bicycle racing and heavily modify the China Girl engine and exhaust system and option it with a different carburettor.
 
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