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Ok, Bill, I think we agreed that a stock Renesis could be
cheaper than a PP (all depending on price paid for either, of
course).
However, I'm not certain I fully understood whether my
comment about the Renesis betting a better specific Fuel consumption than a PP
was an area of disagreement. It appears it was.
I must admit some degree of ignorance in this area ,
however, I always thought that getting better SFC was due (at least in part)
better use of each unit of fuel to produce useful mechanical work. So, if
I understood you correctly, you are saying that the PP which has all this
overlap gets a better SFC than the Renesis which can better contain the
combustion process (no overlap). I must admit that surprises me.
But, always willing to learn.
ED
----- Original Message -----
Sent: Tuesday, June 19, 2007 1:19
AM
Subject: [FlyRotary] Re: Fw: Different
Rotary Port configurations
Renesis will undoubtedly get a better specific fuel consumption than
a PP.
So for those that want the utmost in power, it sounds
like the PP is the
way to go. For other cheap old chaps the
Renesis would appear to offer a
cost effective power
increase.
Ed
Here Ed I have to totally DISagree. The side ported engine is used
to provide more power, and has bigger side ports only workable with the
Renesis, but must also pass smog regulations and provide low-end
torque for car use. The need for the higher redline is the total giveaway. For
ANY i.c.e. the key to higher bmep is higher RPM. Spin your 13B to 9k and
provide it with an adaquate intake and exhaust I would bet money you will be
within a few HP. While I don't want to sound like a broken record, and
certainly not trying to be contentious, Mazda built the 26B for use in a race
using an economy formula. If side ports were more efficient they would have
used them! P-ports make more power, but in the low to midrange so
critical in a car they are much dirtier on HC. I really believe that the
Renesis came from Mazda's hydrogen experiments. The ability to produce large
ports WITH NO OVERLAP was critical to the success of that project. Much talk
has been made of the fact that p-port rotaries have considerable overlap in
the exhaust to intake phase. So does every high performance piston engine ever
built. Tuners have even found the overlap phase to be beneficial to
performance when the engine is properly tuned. The reason for the renesis is
IMHO the need to pass smog and provide competitive power, Not that the Renesis
is the "best" configuration. I'm glad they're building it since it is the key
to Rotary survival. I simply harbor no delusions that Mazda wouldn't run a
p-port with variable length intake tract if smog and noise would allow it. The
advent of truly functional Direct injection may make the return of p-ports
possible, but there is now a lot of inertia against them.
As for cheaper I agree. Anything over-the-counter is a less
expensive solution!
Bill Jepson
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