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Date: Wed, 31 Mar 2010 01:09:18 -0400
Message-ID: <w2h1ab24f411003302209o53ab4f7dodfd0e6d32618b084@mail.gmail.com>
Subject: Tuned lengths?
From: Lynn Hanover <lehanover@gmail.com>
To: flyrotary@lancaironline.net
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A "tuned" intake covers a wide Varity of techniques ranging for Hermholtz,
RAM, Dynamic Intake, Inertia, etc,.  There are basically three conceptually
different approaches although they tend to merge under certain conditions.
You have the resonant tuning, the pulse tuning and the inertia turning
concepts.  However, truth be known all three phenomena occur in most intake
systems - it's a matter of emphasis.

The thing that really complicates it is the fact that within any induction
or exhaust system you have Finite Amplitude Waves - the power of these pulse
makes a 135 db sound wave very puny - these pulses can actually pound metal
apart.  They do not interact linearly as do "sound waves" - in fact they can
respond in what at first seems to be weird ways.  For instance they may
reverse there "polarity" depending on whether they encounter an open or
closed termination.

It has only been with the advent of digital computers has it been practical
to even try and model the effects of these waves in an induction system.  I
find them fascinating.

Here are a few references that some of you might find interesting.

http://home.earthlink.net/~redcat/pulse_ram/theory.html

http://www.motionsoftware.com/simtech.htm

http://www.proracingsim.com/dynomationmainpage.htm

http://www.audietech.com/DMfeaturetable.htm


Ed Anderson
Side intake port engines produce different tuned effects than do Periphery
ported intake engines.

Side exhaust ported engines produce different tuned effects than do
periphery ported exhaust engines.

The most powerfull engine would be the Periphery intake and exhaust ported
engines.

Although the intake and exhaust open and close events are reported in
degrees of crankshaft rotation
just like a side port engine, the periphery ports never actually close. So,
tuned lengths produce bigger changes than in the side ported engine. So, one
end of the tune length is virtually open all of the time, and worse one end
is exposed to changeing pressures all of the time.

The overlap (Intake and exhaust open at the same time) is huge. So exhaust
back pressure can poison the intake quite badly.

In the side intake ported engine one end of the column is closed solid by
the side of the rotor. Intake and exhaust overlap may be minimal or
extensive. Column lengths produce crisp tuning. Overlap with peripheral
exhaust ports may have less effect. Exhaust back pressure can remove much
power.

Side intake and exhaust Renesis) may have no overlap at all. The center
exhaust ports share an exit that is too large right at the port face. Even
with no overlap, the intake can be poisoned by exhaust gasses being held in
the chamber by a poor exhaust system. Exhaust system has three outlets

Possibly less sensitive to back pressure than other designs When converted
to a Periphery intake port, may still have low overlap.

Lynn E. Hanover.

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<div>A &quot;tuned&quot; intake covers a wide Varity of techniques ranging =
for Hermholtz,<br>RAM, Dynamic Intake, Inertia, etc,.=A0 There are basicall=
y three conceptually<br>different approaches although they tend to merge un=
der certain conditions.<br>
You have the resonant tuning, the pulse tuning and the inertia turning<br>c=
oncepts.=A0 However, truth be known all three phenomena occur in most intak=
e<br>systems - it&#39;s a matter of emphasis.<br><br>The thing that really =
complicates it is the fact that within any induction<br>
or exhaust system you have Finite Amplitude Waves - the power of these puls=
e<br>makes a 135 db sound wave very puny - these pulses can actually pound =
metal<br>apart.=A0 They do not interact linearly as do &quot;sound waves&qu=
ot; - in fact they can<br>
respond in what at first seems to be weird ways.=A0 For instance they may<b=
r>reverse there &quot;polarity&quot; depending on whether they encounter an=
 open or<br>closed termination.<br><br>It has only been with the advent of =
digital computers has it been practical<br>
to even try and model the effects of these waves in an induction system.=A0=
 I<br>find them fascinating.<br><br>Here are a few references that some of =
you might find interesting.<br><br><a href=3D"http://home.earthlink.net/~re=
dcat/pulse_ram/theory.html">http://home.earthlink.net/~redcat/pulse_ram/the=
ory.html</a><br>
<br><a href=3D"http://www.motionsoftware.com/simtech.htm">http://www.motion=
software.com/simtech.htm</a><br><br><a href=3D"http://www.proracingsim.com/=
dynomationmainpage.htm">http://www.proracingsim.com/dynomationmainpage.htm<=
/a><br>
<br><a href=3D"http://www.audietech.com/DMfeaturetable.htm">http://www.audi=
etech.com/DMfeaturetable.htm</a><br><br><br>Ed Anderson<br></div>
<div>Side intake port engines produce different tuned effects than do Perip=
hery ported intake engines. </div>
<div>=A0</div>
<div>Side exhaust ported engines produce different tuned effects than do pe=
riphery ported exhaust engines.</div>
<div>=A0</div>
<div>The most powerfull engine would be the Periphery intake and exhaust po=
rted engines. </div>
<div>=A0</div>
<div>Although the intake and exhaust open and close events are reported in =
degrees of crankshaft rotation</div>
<div>just like a side port engine, the periphery ports never actually close=
. So, tuned lengths produce bigger changes than in the side ported engine. =
So, one end of the tune length is virtually open all of the time, and worse=
 one end is exposed to changeing pressures all of the time. </div>

<div>=A0</div>
<div>The overlap (Intake and exhaust open at the same time) is huge. So exh=
aust back pressure can poison the intake quite badly. </div>
<div>=A0</div>
<div>In the side intake ported engine one end of the column is closed solid=
 by the side of the rotor. Intake and exhaust overlap may be minimal or ext=
ensive. Column lengths produce crisp tuning. Overlap with peripheral exhaus=
t ports may have less effect. Exhaust back pressure can remove much power.<=
/div>

<div>=A0</div>
<div>Side intake and exhaust Renesis) may have no overlap at all. The cente=
r exhaust ports share an exit that is too large right at the port face. Eve=
n with no overlap, the intake can be poisoned by exhaust gasses being held =
in the chamber by a poor exhaust system.=A0Exhaust system has three outlets=
</div>

<div>=A0</div>
<div>Possibly less sensitive to back pressure than other designs When conve=
rted to a Periphery intake port, may still have low overlap. </div>
<div>=A0</div>
<div>Lynn E. Hanover. </div>
<div>=A0</div>
<div>=A0</div>
<div><br>=A0</div>

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