A lot of little things add up in the HP game.

 > Royce

Very Interesting, Royce.  Racing Beat sells templates for modifying
the exhaust ports depending on what has been done to the intake.  I
worry that opening either the intake or the exhaust just a few thou
too soon will seriously erode performance.  For my ports, I would
like to be a bit more conservative and stay away from that critical
line.  Easy enough to say, but not so obvious when looking at the
housing.  The Leman P Port opened very early, according to the
drawing,  yet it ran great.   Seems to fly in the face of what we
are saying here.

Jerry Hey

Not really Jerry, that engine was "tuned" to the max.  The exhaust system did
a great job of extracting the spent gases, so the intake port wouldn't get so
much dilution.  They also ran it at high rpm's so there was a lot of fresh
fuel charge flowing in through that hugh induction system.
If there was much overlap in the ports they would have still gotten some
dilution.
They were after lots of power and a p-port will make the power at high rpm's.
Look at that chart Paul sent and you can use it along with the plexi to get
your ports in a good situation.
Royce

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2002 All world wide rights reserved.