Homemade reed valve, the search begins

David Bogle

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Jan 11, 2016
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155
Have any of you ever built a homemade reed valve? Know of any good descriptions of the process? Have any pics, videos or links? At best I've been able to find discussions about the best materials to use.
 


butre

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Dec 2, 2013
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2,502
I like using stainless steel shim stock for the petals and mild steel for the reed cage
 

butre

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Dec 2, 2013
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2,502
it's somewhere in my parts bucket, I've been using an RSE valve for the past year. my design was similar to Arrow's valve, just with more steel
 

HeadSmess

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May 17, 2010
Messages
3,049
why the obsession with reed valves?

what propaganda have you been reading?

i recall an estonian posting a thread years ago with a vid of some estonian MB racing, where people where hacking into the crankcases and welding in manifolds for proper reed cages from REAL engines...but havent ever been able to find the thread again...

if it isnt feeding directly into the crankcase...forget about it. half piston port, half reed valve is doing nothing but wasting time and money. all you are doing is placing a restricted passageway onto an engine with an already restrictive intake port.

typical chainsaw/brushcutter easily out performs the HT engines, but still use piston ports 99% of the time.

sheesh, i even figured out a decent way to do drum/disc induction but yeah...why bother? save up and get a denardis.
 

David Bogle

Member
Joined
Jan 11, 2016
Messages
155
why the obsession with reed valves?

what propaganda have you been reading?

i recall an estonian posting a thread years ago with a vid of some estonian MB racing, where people where hacking into the crankcases and welding in manifolds for proper reed cages from REAL engines...but havent ever been able to find the thread again...

if it isnt feeding directly into the crankcase...forget about it. half piston port, half reed valve is doing nothing but wasting time and money. all you are doing is placing a restricted passageway onto an engine with an already restrictive intake port.

typical chainsaw/brushcutter easily out performs the HT engines, but still use piston ports 99% of the time.

sheesh, i even figured out a decent way to do drum/disc induction but yeah...why bother? save up and get a denardis.
Obviously you're not familiar with my postings or as you put it
"My obsession"
 

HeadSmess

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Joined
May 17, 2010
Messages
3,049
true that, i got confused with someone else :)


my bad...

still...they aint worth it...unless you feel like seriously modifying the crankcase.

modified a cylinder at one point to take the reeds from the lil CAG 49cc pocket rocket motors.







i thought they were a good idea at one point myself...

can you tell this project was what made me convert my mill to cnc?

and can you see the minor stuffups that prevented it from ever being finished? :D

the first and biggest one was using the handy chunk of alloy i had lying around rather than get something slightly thicker... 3mm more and it might have worked. i took one cut too deep, broke through.

think its all still in a box somewhere but then again, i probably scrapped most of it.

i have a niggling memory about the reed cage breaking in the final stages that finally had me move on to other things...
 
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David Bogle

Member
Joined
Jan 11, 2016
Messages
155
true that, i got confused with someone else :)


my bad...

still...they aint worth it...unless you feel like seriously modifying the crankcase.

modified a cylinder at one point to take the reeds from the lil CAG 49cc pocket rocket motors.







i thought they were a good idea at one point myself...

can you tell this project was what made me convert my mill to cnc?

and can you see the minor stuffups that prevented it from ever being finished? :D

the first and biggest one was using the handy chunk of alloy i had lying around rather than get something slightly thicker... 3mm more and it might have worked. i took one cut too deep, broke through.

think its all still in a box somewhere but then again, i probably scrapped most of it.

i have a niggling memory about the reed cage breaking in the final stages that finally had me move on to other things...
My obsession is with learning how to make my own parts instead of buying everything, I'm curious about what works or doesn't work for others
 

lazylightning@mail.r

Active Member
Joined
Jun 2, 2011
Messages
320
Have any of you ever built a homemade reed valve? Know of any good descriptions of the process? Have any pics, videos or links? At best I've been able to find discussions about the best materials to use.
Hi! I'm in the process of a build and it will have a homemade reed house. The actual reed (w/reeds) is something I picked up at the scooter shop. A four petal job for $10. I may change the metal petals to some carbon 0.5mm in thickness. I'll send some pictures when it wil be ready. You will have to port the piston or the reed will be of no use. A reed plus a speciafically tuned torque pipe will do alot to boost power, but you will have to increse the flow volume of those transfers and move them towards the intake side without getting too close to the piston ring pins paths. A third port will be needed for sure. The intake diameter should be wider than stock, as should the carb diameter. The maximum carb size is 21 mm for a 66cc engine when using a reed. A 22mm can be used on a piston port 66cc engine. I am using a conrod and bearings from a Yamaha Jog, it is 5mm shorter, so I have to lathe 5mm from the bottom of the cylinder using a special cylinder holder that I made. I also had to remove some metal from the bottom of the piston so it doesnt hit the flywheel when using the shorther Yamaha conrod. Here's some pictures of what I got going so far.
 

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