Corrected intake flow for reed valve

Discussion in 'Performance Mods' started by jaguar, Feb 10, 2013.

  1. jaguar

    jaguar Well-Known Member

    I disliked how the tip of the reed petals of the Rock Solid reed valve were "up" from center so that mostly only the lower petal would be able to respond to crank vacuum. So I hacksawed off the intake, redrilled and tapped two mounting holes, and put it back together. Now the reed valve is centered and the cranbkcase compression ratio has been increased. Here is a picture: shortestintake.jpg

  2. geebt48cc

    geebt48cc Member

    That is one of the reasons that I went with the Arrow reed valve set-up. I realize that you can loose a bit of crankcase compression with the Arrow reed to length?! After I drilled into piston with ported intake, it has very much improved the total compression flow/performance!!~.

    PS--I also am getting there with torque pipe fun!~
    Last edited: Feb 11, 2013
  3. Fabian

    Fabian Well-Known Member

    I'm scratching my head at your explanation, because from what i understand the RSE reed valve is a symmetrical design and it sits evenly in the intake port. When the piston is at top dead centre the air/fuel mixture doesn't leave the upper reed petal and travel vertically and hit the intake port roof?

    How does moving the reed valve intake in a vertical fashion (on the intake port mounting face) increase crankcase compression?

    I somehow suspect that those modifications won't make an ounce of difference to performance at any rpm...
  4. Fabian

    Fabian Well-Known Member

    Unless you have hacksawed off the cylinder intake port mounting face; altering the angle of the reed valve in the intake port as well as moving the reed petals closer the axis of the crankshaft?

    and that's a bit of messing around for what will end up as marginal if any improvement with a standard exhaust system, which most people use.
  5. geebt48cc

    geebt48cc Member

    I do understand your point Fabian. Yes, I do like what I hear best of RS reed, but finding that there are pro's with the Arrow reed also. I've not stuffed the crank, but once I opened piston up on intake side (with a closer than not torque pipe) she gains or holds speed up 98.8% of all hills. The only thing I don't have, is a shift kit...........(but not in a big hurry considering streets the bike is used)

    Uno, it is just a bicycle. So sure, as long as I've got to grunt to eat those hills, while keeping 24-33 mph, I'm ok with all. That's pretty darn good enough considering what it's got on its back...........:)

    .............O'yeah, and we are talking about a china engine engineering here. Uno, it's to bad, because the HT's are really a very good idea that has been thrown together in order to make a fast buck?

    Last edited: Feb 12, 2013
  6. Fabian

    Fabian Well-Known Member

    Glen, your life won't be the same once you've fitted your shift kit.

    Be warned that the shift kit will change your life and sometimes a good thing isn't always the best:

    When you come home from a ride (remembering every single gear shift in your head), and your wife/girlfriend has had a hissy fit over something trivial and promptly asks you to "get that smile off your face or i'll remove it myself" there will be huge problems to deal with because that smile isn't going to be removed easily.

    When you come home from a ride, (remembering every single gear shift and the road incline and the exact maximum cylinder head temperature on every hill climb, stored away in your head), and your wife/girlfriend has a trivial hissy fit because you are 20 minutes late and she was worried sick about you, and tersely directs you to remove that smile from your face, there will be huge problems to deal with because the only way that smile is coming off is if it's surgically removed.

    When you come home from a ride (remembering every single gear shift and the road incline and the exact maximum speed on every hill, stored away in your head), and your wife/girlfriend has a trivial hissy fit because you are late and won't be able to make it to her sisters bridal party, there will be huge problems to deal with because she will promptly let you know that divorce is the only option.

    I have gotten myself into so much trouble after fitting my shift kit because i couldn't stop riding my bike and ended up trashing so many personal appointments in my life.
    One lady said to me: is that stupid bike more important to your life than i am - - - my reply was "yes it is". The outcome in the restaurant wasn't a pretty scene...

    Be warned - a shift kit has the ability to give you so much enjoyment that it should come with a surgeon generals health warning :grin5:
  7. geebt48cc

    geebt48cc Member

    I'm sure you are VERY right Fabian. Yes, I'll get one I'm sure, but if I keep on procrastinating, they are going to be big $$ for the bike world?! I stop and think, "Wonder why I'm putting so much time into a darn bicycle?" I mean, no matter what color or new gadget I put on it...........It's still going to be a simple bike?! I'm sure that it even gets to me more considering my past days riding big sport tours............... Anyway, there's just something about the lower cost, and the simplicity of these little toys.

    Fabian, I'm also thinking, that if I just keep the bike in a more limited state without a shift kit, I'll not tempt myself from having to have a full blown out motorcycle?!
  8. jaguar

    jaguar Well-Known Member

    Fabian, your last assessment is correct.
    I just posted this for entertainment purposes. I know hardly anyone other than a serious racer will do the most extreme things I do to mine.
    The piece of intake manifold I cut off measures 7/16" at the top and just a bit under 1/4" at the bottom. So not a lot was cut off, just enough to get the mounting angle for the reed valve in line with the flow.
    ha! JNMotors doesn't want me to share all my secrets with ya'll. I assured him that no one was going to go to all the trouble I have to perfect my engine.
    Last edited: Feb 12, 2013