Does anyone know if the RX8 rotors can be used in a   20B?  How can I
identify the various Rotors that have been  produced throughout the years??

Don

My advice is call Dave Lemon at Mazdatrix or Jim Mederer at Racing Beat
and ask them. If anybody should know if it works these guys should know.

Paul Lamar


Don,
Let us know what they say.  I was told they can be used in a 13b or 20b and
I have a set that I'm planning on using.  Paul, you'll recall a few months
back we had a discussion on whether Renesis apex seals would work on a
p-port.  You ran the numbers and concluded that they should work in a p-port
engine.

The Renesis rotors also have an 3rd oil seal.  (Something to do with the
side exhaust ports?)  So, I was advised to leave one out and just run two
(same as the 20b seals).

Finally, the Renesis rotors are lighter than the 20b rotors, so you'll need
to have the rotating assembly balanced.  Not a big deal (I hope).

Anyway, I have tried fitting them in my engine and they appear that they
will work.

Paul, how much additional hp is this worth?

Mark S.

P.S.  They're not cheap!

Not much. Compression goes up from 9:1 to 10:1. It may help BSFC slightly.
Nobody ever studied this as far as I know for a p-port in the range of
6000 to 7500 RPM. In a side port engine there is a 5 to 10 percent
improvement in torque the 3000 to 4000 RPM range. Some of this is in
the books "Rotary Engine" by Kenichi Yamamoto. Download for free.

http://www.rotaryeng.net/interesting.html
http://foxed.ca/foxed/index.php?page=rx7manual

Don, I suggest you make some category folders in your email program and drag these
answers to those folders so you don't need to ask these questions over and over
again. By know you should have heard about and downloaded this book.

Paul Lamar