reed valve questions

I'm thinking of doing this myself. Let's keep this thread going and tell how we do what we do. Could be a learning experience.
 
maximillian said:
i just got it and its a shade too small. i would get a bigger on if i was going to buy another one
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Hmmm...Sounds like we need to find out how big the chainsaw is that this reed valve belongs to, then research a bigger chainsaw. I only hope this reed valve isn't the biggest they have.
 
I typed reed valve in their search ,,there are a lot of different designs,I think we need to figure out how to tell the CC's of a saw
 
I looked for 66 cc chainsaw and finaly found 60 if i remember ,it may have been the carb and reed valve at the end of the list that led me to it,I think the saw was huscavara(spelling) Rancher
460 or something and the thing wasn't that big in the pics,and a 20-24 inch bar is all,I've had larger ones
 
Piston port motors are alot different than reed valve motors....I dont think fitting reeds on would help....please correct me if im wrong.....

Case induction is a possibility.......
 
Slowrollers said:
Piston port motors are alot different than reed valve motors....I dont think fitting reeds on would help....please correct me if im wrong.....

Case induction is a possibility.......
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Well, I know the piston port design was meant to use the natural direction of airflow and backpressure to keep the airfuel mix in the area of the cylinder just long enough for the piston to squeeze it and the spark to blast it. What I'm hoping a reed will do (which may be very little) is keep more of the airfuel mix in the cylinder, rather than some of it always blowing back up the intake manifold. On my old bike, it was never very serious, but it was always there. That's wasted power.
And if the reed doesn't work, we can take it off and say we tried.
 
Allen_Wrench said:
Well, I know the piston port design was meant to use the natural direction of airflow and backpressure to keep the airfuel mix in the area of the cylinder just long enough for the piston to squeeze it and the spark to blast it. What I'm hoping a reed will do (which may be very little) is keep more of the airfuel mix in the cylinder, rather than some of it always blowing back up the intake manifold. On my old bike, it was never very serious, but it was always there. That's wasted power.
And if the reed doesn't work, we can take it off and say we tried.
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I'm about to try this, ordered the reed. I've been reading both the other threads and someone listed a port modification from Hodaka to control the case pressure. That tells me a reed could do something when added to an engine built without. :)

I'm guessing any reed from a saw shoule do, but I seriously dont know and will find out.
 
FreeWheeler said:
I'm about to try this, ordered the reed. I've been reading both the other threads and someone listed a port modification from Hodaka to control the case pressure. That tells me a reed could do something when added to an engine built without. :)

I'm guessing any reed from a saw shoule do, but I seriously dont know and will find out.
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I'm still on the mend, so I haven't been able to do much tinkering on my end. But if you manage to get positive results yourself, please post. And let us all know how you did what you did, when you can. There are a few of us who want to try this. What you learn could pave the way. :)
 
we tried using reed valves on the HT. didn't work out very well. the piston port is way different from a reed port or case port engine. you also need a good sized hole cut into the right spot on the piston skirt to use reeds on a jug inlet engine. heres what we came up with. but we gave up on it after finding a much better running engine by just raising the ports and using an expansion chamber exhaust.
manifold.jpg
 
Imagine a Chna Wench on steroids: Kawasaki 750 H2

The 750 H2 stock is a piston ported 2 stroke and this guy fit reeds to it. His cyclinder modification looks alot like that Hodaka modification. Interstingly, somewhere in that link he talks about the loud rattles and slap that these engines had. Sounds familiar.
 
camlifter said:
we tried using reed valves on the HT. didn't work out very well. the piston port is way different from a reed port or case port engine. you also need a good sized hole cut into the right spot on the piston skirt to use reeds on a jug inlet engine. heres what we came up with. but we gave up on it after finding a much better running engine by just raising the ports and using an expansion chamber exhaust.
manifold.jpg
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OK, so did you lower the intake port and cut holes in the piston?

I read in another thread that someone had trimmed their piston skirt AND lowered their port without adding reeds and lost all power. It was suggested that adding reeds to those failed mods would have restored power plus some.
 
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