Frame Induction

Discussion in 'General Questions' started by JemmaUK, Jan 5, 2008.

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  1. JemmaUK

    JemmaUK Guest

    Hi all,

    There have been some discussions regarding induction and exhaust systems being built into the frame..

    I have come across some information that seems to indicate that some of the old cyclemotors and early mopeds used a novel method of minimising 'induction roar' namely using the frame as an intake manifold into the carb..

    I was wondering if anyone had any comments and ideas on this...

    Jemma xx

  2. gone_fishin

    gone_fishin Guest

    beyond noise-control, what effects might that have on performance?
  3. JemmaUK

    JemmaUK Guest

    So far as I can tell it might actually improve power - specially if the inside of the frame tube is prepared properly to provide better air charge swirl..

    So far as I can see the only problem would occur if the intake to the carb were to be larger than the available intake size and area at the free air end or if the pipe itself were narrower...

    Jemma xx
  4. BSA

    BSA Guest

    How the heck is that one done. How is it connected to the frame?

  5. fetor56

    fetor56 Guest

    To my way of thinking any air restriction reduces performance.Intake seems critical for proper engine "breathing" and for the most part is under-rated.
    I posted a thread here about our HT air intake with little response.
    Sometimes i agree with manufacturers setups and sometimes i don't,but i DO believe in experimentation.....try it,see what happens. :smile:
  6. JemmaUK

    JemmaUK Guest

    Properly designed and set up aka the 'Sonoramic' long intakes - this system can provide alot of extra power - however the sonoramic system used a complex intake manifold for the V8 it was fitted to.

    Specifically each cylinder bank was fed by a 4-barrel carb with a separate intake to each cylinder from the carb. These were 30" in length and were twinned from 15" to form a split plenum effect (similar to the tuning effect on the much later Rover Vitesse SD1).

    The idea was like a tuned pipe induction in that the pipes were set to provide their ram effect at a given RPM, for example 2800(for torque/power) although it could probably be tuned to come in higher for a power increase at full throttle..

    With a single cylinder 4 stroke valved engine the same setup should be easily possible - the only requirement is the calculation of the intake lengths for engine boost at given rpms (which would need a rolling road most likely)...

    The idea of frame integration:- this should be fairly simple if a person has the ability to build frames already. Once the required rpm/ram point is decided and the relevant pipe calculated the section of frame can be fabbed and installed

    The problem with two strokes of the reed valve variety is that of timing the inlet pulses and the scavenging exhaust pulse, get it wrong and it will throttle the engine. As to the revolving valve type the problem is probably the same.

    Jemma xx
  7. Klox

    Klox Guest

    Interesting link you supplied.... Mankind and it's search for more and more power. That's why there is so much different ways of achieving the same (ultimate) goal. The more modern approach to ram induction is Bmw's Vanos & Honda's Vtec.

    Years ago Kawasaki had a disc valve 2-stroke engine. It was a 125cc "road scrambler". The kawa's engine had more torque than the equivalent Yamaha (boost bottle & reed valve) at lower rpm, but would run out of steam at the higher end of the rev range. Obviously it's not fair to just compare both designs on just this one point, there are many other factors to take into consideration too!

    Anyway, this was really an interesting point you raised. It could be a lot of fun "exploring" the frame induction idea....