rse reed valve with or without intake port extending or holes drilled in the piston.

Discussion in 'Performance Mods' started by gamer121ps, Feb 23, 2014.

  1. gamer121ps

    gamer121ps New Member

    do i really have to drill holes in the piston skirt and or elongate the intake port to increase the duration of the intake? cant i just install the reed valve on my specific engine without modifying the engine itself to see a power increase? i know i will have to change to a larger carburetor jet. will that be enough to see a good power increase?
     

  2. jaguar

    jaguar Well-Known Member

    without drilling holes in your piston you will see a power decrease.
    the boost port, after you make it, will also increase engine power.
     
  3. gamer121ps

    gamer121ps New Member

    can i just extend the intake port? or just put holes in the piston skirt? or both?
     
  4. Fabian

    Fabian Well-Known Member

    You do not need to do any modifications to the piston or the intake. The major benefits of the reed valve are improvement of low and midrange torque. This lower usable rpm band has reduced air flow requirements; being less demanding of the porting configuration.
    Having said that, there may be small gains in power or torque by modifing the piston and intake tract.


    Of course you can do that, but the reed valve intake will provide (at best) only marginal improvement in maximum power, but substantial improvement in low and midrange torque, using a standard exhaust system.


    Every engine needs to have the jetting optimised for the fuel in your location as well as the atmospheric conditions in your location. When the engine is correctly jetted, it will provide more power than a stock standard jet, if that particular jet doesn't provide the correct air/fuel requirements for your location.
     
  5. jaguar

    jaguar Well-Known Member

    Opinions are like aszholes, everyone has one.
    I always ignore opinions and refer to scientific testing. That is what I show on my page about reed valves. There are dyno results from a Zundapp and a Bultaco that show that a reed valve (piston holed and boost port) decreases low end power and increases top end power.
    Go there and see for yourself.
     
  6. Fabian

    Fabian Well-Known Member

    The porting size and shape and design specifications as well as the expansion chamber design of the Zundapp and a Bultaco are completely removed from the Chinese 2-stroke bicycle engine.

    I am happy with the low and midrange torque improvement that the Rock Solid engines reed valve produces. If it didn't offer an improvement, it wouldn't be on my bike.
     
  7. jaguar

    jaguar Well-Known Member

    the exception is that a reed valve with torque pipe gives better low end than a piston port intake with extended intake and standard pipe.
    When a reed valve is fitted on an engine with expansion chamber it allows additional fuel mixture to come thru the reed valve when the return vacuum pulse from the pipes diffuser arrives back at the cylinder. This can't happen with a piston port intake.
     
    Last edited: Feb 27, 2014
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