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Message
Has anyone ever joined the intermediate housing ports by
removing some of the material between the ports in the housing to make a larger
single port and runner? If so, did it help or adversely affect
operation?
Hi
Cary,
Funny you should ask, as
I've been wondering about the very same thing. You've no doubt heard
me whining about how I believe my 40mm runners and TB barrels (primary and
secondary combine in the cast intake, then one runner and barrel for each rotor)
are likely too restrictive.
In talking to TWM a
while back, they suggested a balance tube from one runner to
the other. This would allow each rotor to draw air from both barrels
of the TB. They didn't know how well it would work, but saw it as the only
way to get more effective TB area with my current intake. In thinking
about this, I came across the idea of simply milling out the divider between the
primary ports inside the intake flange. Unfortunately, I have the same
question as you do as far as how well it will
work.
On one hand, it would
have to give the engine easier access to air, but there is some
concern about interference between the two rotor pulses. I haven't
really studied the intake and exhaust timing, but if there is any overlap
between the intake of one rotor and the other, then I can see this being very
bad.
Imagine one rotor having
it's intake cycle. The port opens, there's a large rapid surge
of suction pulling air into the rotor housing, but as it nears the end
of the cycle, that suction subsides and the air is just more or less coasting in
as the port starts to close. Now, imagine the second rotor starting it's
large suction portion of it's cycle as the first rotor is coasting.
The second rotor will be perfectly happy to suck some of the air and fuel
out of the first rotor, as it also sucks new air in from the
runners.
I guess I need to study
the timing, but ported engines would be worse. Fortunately,
the primary porting isn't usually quite the same as the secondary, so
perhaps there's a better chance it can work. I'm not quite ready to
mill out that divider yet though.
Cheers,
Rusty (too many
experiments)
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