Reed valve on the cheap

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sharkcruiser

sharkcruiser

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Jul 14, 2008
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charleston sc
DanielMaia said:
I didn't get some of what you said..

I can make a reed valve and sell for cheap? where i can get one? it's a specific valve that only mechanics have? the plates are only to hold the reed, right?

thanks reg



This is the valve, right? you made it?
Click to expand...
The reed in the picture I removed from a chainsaw that is probably as old as I am. I found it in the trash. I just knew what I was looking for is all. I made the body of metal that is holding this piece out of another piece of scrap that I found in the trash. The same process could be repeated many different ways. This was just what I had.
 
sharkcruiser

sharkcruiser

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I want to try the Walbro carb that belongs on the reed soon. there will be no need for the intake manifold with that. I do agree with your suggestion. I may refine it into a product eventually. I also kind of dig making knowledge of my experience available so anybody with the motivation can benefit. This bike "Hobby"/"obsession" is just so d@*n fun! Check out the link below. If I find some plastic blanks it might be game over. That is my little helper there

YouTube - shopbot
 
sharkcruiser

sharkcruiser

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Daniel,

you see the little metal "trap door" that is the one way only for the fuel/air coming from the carburetor. The other is a piece of discarded metal that I used for the plates. Hope this helps
 
S

Scotchmo

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Jun 23, 2009
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Another modification that should complement the reed valve is to trim the piston skirt on the intake side. The reed valve allows you to have the intake port open longer while still restricting backflow into the carburetor. You can get the high rpm power boost provided by trimming the skrt while still retaining the midrange power.
 
sharkcruiser

sharkcruiser

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Yes I agree. I had already trimmed it up when i got the motor. The things that are going to have improvement now are to do a proper port job on the transfer ports as well as adding boost ports, horizontal tapering of the exhaust port and properly beveling the piston crown. This will all probably lead to R I P for my tired little engine but its good practice for the next one!
 
DanielMaia

DanielMaia

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Jun 24, 2009
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Opening that "port", will raise the consumptions, right?

Certainly i'm wrong, but i take the exhaust off, and see inside the piston, and the exhaust port is almost covered by piston (when this is fully in top).

Hope that you understand, but i put a picture if you didn't :)
 
sharkcruiser

sharkcruiser

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DanielMaia said:
Opening that "port", will raise the consumptions, right?

Certainly i'm wrong, but i take the exhaust off, and see inside the piston, and the exhaust port is almost covered by piston (when this is fully in top).

Hope that you understand, but i put a picture if you didn't :)
Click to expand...
Daniel, I did not see a picture but you are correct with the consumption. The idea is more air, more fuel, equals more power. In the states there is a saying " there's no substitute for more cubic inches." CC's in our case. In porting the motor you actually increase the volume of the the engine and how much air/fuel it can hold. Even though it is on a very small scale it ultimately increases the power produced. It also helps to get the air/fuel into the cylinder to combust which is essentially consuming more.

If I understand correctly what you are saying about the piston in the exhaust port, it should be covering the hole up completely. If its not then there is something wrong there.
 
sharkcruiser

sharkcruiser

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Update:

So far everything is still running. Chased down a few painfully annoying air leaks. Runs great now. Everything has turned out better than I had expected.

I think it performs really well with the stock carb and manifold so I will be trying the Walbro HDA carb soon.

I will tinker with that one for a while and post about the comparison.
 
Pitchfork311

Pitchfork311

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Apr 29, 2009
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Hey sharkcruiser, you have inspire me to do my own reed valve mod. I picked up a chainsaw reed valve and am currently attempting to make a single piece bracket to mount it to the engine.'

Here is a pic, I will just be bolting it up through the bolt holes, it is a perfect size and fit. Only problem will be the header. I will either costume one, or cut one of jim's headers short to make it fit. Hope it turns out like yours has!
 

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sharkcruiser

sharkcruiser

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Jul 14, 2008
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charleston sc
Awesome! Looks like an even easier reed to mount than the one I have. What kind of chainsaw did your valve come from? Mine was from a Homelite 33cc super2. I am glad to see that someone else is benefiting from my experiment. I think that ABSplastic or Polyethyline plastic would be way easier to fabracate a mount from. Like a piece of an old cutting board or something. Keep us posted!
 
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Pitchfork311

Pitchfork311

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Apr 29, 2009
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It cam off of an Echo CS-280EP 30 cc chainsaw. The inlet hole and the bolt holes line up perfectly with the stock intake. It basically will bolt right up. I'm in the process of making a bracket that basically will just be a gasket that will provide the clearance between the reed valve and the engine. I'm pretty excited. I cut the piece yesterday. Just laying out the outline for the cut depth and when I get home I got to measure the intake port on the engine. Hopefully if will be done sometime next week. I picked up a CNS carb that I am going to start using once I get this reed valve sealed and ready.
 
V

vicsvw

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May 12, 2009
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Any old Go Cart shops would have a verity of read set-up's. Some have a funnel look with the reads around the out side so the air does not have to make a 90 degree bend. We have found cutting ports in the piston work better then shortening the intake skirt. I will try to find a How to article that Hodaka came out with. It was in detail putting a reed on there 100cc motor. The reed set up was used for more low end torque. Vic
 
sharkcruiser

sharkcruiser

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Jul 14, 2008
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charleston sc
Yes, I did get most of the performance in the low end torque. The top end suffered, only slightly, until I rejetted the carb. Now the midrange has blown me away. The motor wants to wind up so many rpm's at part throttle that I don't even open it up to WOT.

I really wanted to try the other carb but the bolt spacing is 1.5mm too narrow. I have another engine coming in the mail and once that gets here I will do the boost porting.

I have a suspicion that the clutch is so "seasoned" that the new, quicker, acceleration is really wearing it out.

Pitchfork, I am out of town this week but I have tons of pics of the process I went through in making the whole setup. If you have any questions I'll do my best to help out. I think this is such an exciting project and literally cannot wait to hear how yours turns out.
 
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gberry50

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Jun 16, 2009
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snowflake,az
.duh.Found pocket bike reed valves on ebaythey look like two stage . I ordered two will update with results and pics of mod with the tuned pipe I am hoping for 50 mph oh s@#t hang on hope the wheels
are still on this walmart pos when I get to wot
cost 11.95 + shipping
 
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