I'm inclinded to agree, Tracy. I believe
PowerSport claimed 215Hp for their P port installation - which appears
realist. In fact, assuming 100% Ve and a best power
A/F ratio of 12.65 it looks like you would need to turn over 7500
rpm to get 240 HP.
You can further enrich the mixture and pick up
some additional HP, and perhaps get a Ve greater than 100% with some
induction/exhaust tunning, but still seems a bit much to get 240HP at
6000rpm without forced induction.
I also found this message fragment regarding
the dyno test, I presume that Mazdrix/Lamar will put this mod into
production given the potential market for it.
"Mazdatrix recently dyno’d a N/A
peripheral-ported 13B for Paul Lamar at 250hp @ 6000rpm, running a
carburetor. That is an easy 125hp/rotor, and 250 hp from a 195#
engine."
In my research, I pulled up the data on the 4
rotor race engine that Mazda was so sucessful with which used a PP and slide
throttle (similar in concept to Paul's) and adjustable telescoping
inlets to tune the inlet to the engine rpm. This engine also had
3 spark plugs per housing and 10:1 compression rotors.
The attached graph (apologize for its
quality - but, best I could do) shows that at 6000 rpm (power oriented
settings rather than fuel efficient settings), the engine produced a total
of around 360KW which equates to around 482 HP. So given 4 rotors are
producing that it would equate to 482/4 = 120.5 HP/
Rotor.
Assuming it scales linearly - then 2
rotors should give 241 HP at 6000 rpm. Interesting that Paul's
engine does better at 250 Hp than produced by the Mazda racing
team without the 3 spark plugs, telescoping inlets or 10:1 compression
rotor. Humm, Perhaps the racing teams should consider
hiring Paul.
That said, unless you have/know the
actually conditions under which the dyno test is being done and the points
the data is taken at, there is simply a lot of room for
"interpretation".
Ed
----- Original Message -----
Sent: Sunday, May 13, 2007 12:02
PM
Subject: [FlyRotary] Re: EC2 smoke
question
Outstanding is right. It's so outstanding that I tend to put it
in the same category as the other info he has dispensed (I.e.,
smoke). I could be wrong though. All things being equal,
the P Port motor should make more power than the sideport engine.
Just not sure it is THAT much more. Everet Hatch was able to make a
little over 210 HP at 6000 with carefully tuned long p-port runners after
much R&D. I do believe those numbers.
Tracy
----- Original Message -----
Sent: Saturday, May 12, 2007 9:49
AM
Subject: [FlyRotary] Re: EC2 smoke
question
That is outstanding HP, even on a California dyno. Any port
pictures or porting open and close figures?
Sounds like the one to replicate. A typical Weber intake
system from a race shop would be quite short. Not ideal for 6,000 RPM.
Better at 9,500 to 10,000 RPM,
looking for 335 HP.
Lynn E. Hanover
<4 Roto Powers.jpg>
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