Vance W Jaqua wrote:

The Lemans engine had to run on automotive pump fuel and not

nitromethane,

alcohol or any other kind of racing fuel. Those are the rules.

Name another 2.6 L  N.A. street engine generating 250 HP like the

RX8.

I do not think even the Le Mans engine makes 120bhp
per rotor at 6000 rpm, and 13B's are a lot further from that
engine than reworked ports.
Vance

It sure does make 120 HP per rotor at 6000 RPM. There is no

fundamental

difference

in the Lemans engine from your typical 13B engine that would limit
the power at 6000 RPM. Larger P ports are available from Racing

Beat

than

even

the Lemans engine P ports. The main difference was rotor weight

and

that would only affect top RPM. The RX8 probably has the same

weight

rotor

as the Lemans engine.

Yes - the Le Mans is on the pipe by 6000 rpm and is seeing at least

3

psi

resonant boost
and slightly exceeds 120 per rotor.

 Now for Combustion engine 101

I did not use any "bogus displacement for the bmep calculations. The

purest

way to
compute BMEP is to establish the number of power expansions in one

minute

for
the selected operating point and multiply this by the swept volume

of

each

of
those power "strokes". using cubic inches since we are seeking a

psi.

Then

compute the total work during this minute using either torque or

horsepower.

Convert that work into pound inches for dimensional consitancy, and

divied

that
work by the total volume. (does not matter if it is rotors, pistons,

4

stroke, or two
stroke). BMEP is one of the most accepted measure of engine

efficiency

being

a measure primarily of volumetric efficiency and compression ratio.

BMEP is maximum at peak torque since that represents the best

filling of

the

chambers
and of course, it is modified by "boost -  super charging".Some

values

at

peak torque
for familiar engines
RX8                150.2
Chevy truck     157.3   pushrod 2 valves low comp ratio
Cont IO-360     171     pushrod 2 valves low comp ratio - but some

resonant

boost
Hyundia            163
NissanMX         180
Le Mans           211    full race engine - over 3 psi resonant

boost

Ferrari             200    advanced street engine
And you do not want to even see what a stock 13B does. Vance

Your right! I give up! The engine is a shitty 4 liter engine. No more

use

in aircraft. The BMEP is not up to piston engine standards. Besides

all

that

it is missing a bunch of essential parts like pistons, crankshafts and

poppet valves.

No way will the FAA ever certify a rotary.

I only ask one thing Vance. I want you to send me a messages stating
unequivocally, without if ands or buts,  that the 13B is an 80 cubic

inch

displacement engine.

Paul Lamar

Sorry - While I will gladly state that the Wankel is a fine, inovative
engine with
amazing packaging size for the swept volume, and will make a very
satisfactury
aircraft power plant (especially with it's robust construction and

reduced

catastrophic failure modes) - you will see an evil looking fellow with

horns

and tail
lining up to buy long johns and down jackets - before I agree that it is

an

1.3 liter
engine. Although I am a firm advocate of truth and honesty in

engineering, I

have
to admit the fact that Mazda is continuing to screw the Japanese tax man
does not upset me. Vance Jaqua

You must have read my mind. I was about to get on your case. Then you
must also admit your bogus (your word) BMEP calculations are based on your
over estimated bogus displacement :)

You also failed to answer 50% of the exam so you get an F. I will up your
grade to a C - and give you another chance to answer the last question.
Name another 2.6 L street engine that gets 250 HP like the RX8 engine
does?

BTW H. Heisler in his book Advanced Engine Tech also disagrees
with you. He states it is equivalent to a two cylinder four cycle
engine of twice the displacement. Just like a two cycle is equivalent to
a four cycle of twice the displacement. You are out of sync with the world
on this point alone Vance :)


Paul Lamar

Paul - Bogus was your word - NOT BOGUS was my description of computing BMEP
which is
totally valid. The 13B and the RX8 contain 6 chambers, each with a charge of
roughly 750cc.
When the next firing comes up in a rotor, it is NOT that SAME previous
chamber, arriving
magically (your word) recharged and ready to go again. It is the
NEXTchamber, which has
been busily going around the housing doing it's four stroke cycle thing, and
yet the third chamber
 is also coming around, getting it's intake charge, and waiting for it's
turn for firing and power
stroke. Just because it is using one plug does not make it one cylinder.

As to a bogus 2.6 liter engine making 250 horsepower, there are a lot of
engines on the
market for street use that are honestly making over 100HP per liter with old
fashion
poppet valves and connecting rods. The Honda 2000 cc roadster is a
relatively low
cost example, with high end versions of Ferrari and Maseretti exceeding that
value, as well as virtually all of the crotch rocket bikes.

I readily agree that displacement is a "who cares" for aircraft conversions,
and the Mazda
conversion is one of the few auto conversions that comes close to matching
the firewall
foward weight of the Lycosauris. As for Mr. Heisler, you have probably saved
me
the price of a disapointing book - I will stick with Harry Potter - they
admit that it
is fiction - Vance

Better not buy any books on the rotary then as they all disagree
with you on the displacement issue.

You are fixated on the three faces of the rotor when you should be
considering the upper and lower chambers as analogous to the
two cylinders of an equivalent piston engine.


Paul Lamar
 
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