Intake length with reed valve

Spare_Parts

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#1
On the case reed engine I have to change the rubber hose for one with a 45 degree angle. The silicone hose is longer which would allow me to move the carb farther back from the seat tube. I just don't know how this will effect the engine. Will it make more torque like a non reed engine or do nothing? Would be adding about 1 1/2 inch to the tube.
 


FurryOnTheInside

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#2
You have to make it level and make it fit your bike anyway, so I guess you're just asking out of curiosity..
I have only tried one intake length (longgg!) and haven't even fitted the RSE reed yet, but..
Previous threads have indicated that an extended intake should give better low end power, improved hill climbing, presumably improved acceleration too.
It has been said that a long intake harmed top speed in at least one instance.


There's also this page on Jaguar's site:
http://www.dragonfly75.com/motorbike/EIntake.html
 

Spare_Parts

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#3
It can be made the same length it is now but leveled off. I want to move the carb farther back past the seat tube however. The silicone hose is $27 a pop because it is an adapter as well as a 45 angle. Would rather not experiment with hose size. Basically does the reed valve change the theory of the longer intake?
 

FurryOnTheInside

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#4
It can be made the same length it is now but leveled off. I want to move the carb farther back past the seat tube however. The silicone hose is $27 a pop because it is an adapter as well as a 45 angle. Would rather not experiment with hose size. Basically does the reed valve change the theory of the longer intake?
I would expect so. As we would measure intake tract length from slide to piston normally, I would measure from the slide to the reed. It still has to fit your bike though so I wouldn't be too bothered about the theoretical optimum! :)

Your hose sounds interesting. How is it an adapter?
 

gary55

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#5
I'm gona take a stab at it and guess it's a adapter by being a reducing hose that has different sizes on each end?
 

FurryOnTheInside

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#7
Can't save a picture but here is a link.
http://www.hps-siliconehoses.com/hps-32mm-35mm-45-degree-elbow-reducer-silicone-hose.html

Going to look for another option but so far this is the best I came up with. I know it's says not for gas or oil but others are using them.
5mm wall thickness and plenty of nylon reinforcement, looks great actually! :)

Silicone hose is reasonably tolerant of the fuel/air fog, I believe. Just wouldn't be good to have liquid gasoline flowing through it and sitting in there constantly, underneath a car or whatever where you couldn't keep an eye on it. :)

It does seem expensive, although I haven't been looking at hoses in that diameter, only 19mm ID for the stock intake.

The "T bar clamps" shown below it are very nice too. You can screw them down much tighter than the Jubilee® style clamps without the threads stripping or slipping.

I would check eBay before committing, as you might find a better price, but this hose looks like the right item. :)
 

gary55

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#8
Can't save a picture but here is a link.
http://www.hps-siliconehoses.com/hps-32mm-35mm-45-degree-elbow-reducer-silicone-hose.html

Going to look for another option but so far this is the best I came up with. I know it's says not for gas or oil but others are using them.
They are commonly used for reed intakes and work quite well. Good quality is the ticket here. This is a pretty good price for a 4 ply silicone reducing elbow. I would be skeptical of one that was much cheaper. Like Furry said the T clamps are awesome.
 

Spare_Parts

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#9
T clamps are a must with silicone hose for me. I found cheaper on Amazon but haven't found any reviews, have to check other listings after work.

I don't deal with ebay any more. Got burnt buying and selling.
 

gary55

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#10
T clamps are a must with silicone hose for me. I found cheaper on Amazon but haven't found any reviews, have to check other listings after work.

I don't deal with ebay any more. Got burnt buying and selling.
A little different application but with all the oil, fuel, and heat at the head pipe it has held up well for 8 months now. The extra length on the T clamp bolts shows you what a lazy bastard I am.:rolleyes: It seems to isolate the vibration of the engine from the hard mounted pipe keeping the flange from loosening.View media item 61220
 

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