This may be just side commentary and a useless
data point, but for what it's worth here is another somewhat different
comparison. Also I've copied Jon Lauter on this because he must have some
more knowledgeable input. I have one of Jon's Rotary Power Marine
engines in a boat. (Cut that laughter right now). He rated it at 175hp
and has a short manifold to a carb just above it on the intake side of the
engine (also distributer ignition, turbo block and rotors).
My "dyno" comparison is with the previous
engine a 150hp johnson outboard (Will you guys cut that out?) The
current installation must be well over 100lbs heavier due to the conversion
from an outboard to a stern drive but turning only 4500 I'm the same speed
as the 150 hp so I feel pretty comfortable that should I let this get up to
6500 I'd have that 175. Pretty scientific, I know.
Hopefully Jon will respond.
By the way, it is really nice cooling a boat
engine!
Peter
Peter, just the guy I want to talk too.
I'm converting a 4.3L Chevy stern drive boat to rotary power so I'm curious
about what you used to interface the 13B to the stern drive. I figure
I'll be droping about 150 pounds.
I have assumed that RPM is doing jet
drive boats but maybe they have stern drive stuff too? I seem to have
lost Jon's email address so would appreciate it if you could pass that
along.
BTW, I used to fly a 135 HP Johnson
outboard. Now *you* stop laughing : )
Tracy
Hello Tracy.
Phone is: 516-656-5685
When I bought this engine a couple of years
ago, his standard bellhousing was designed to mate to a Morse transmission
bolt pattern (this is a common marine transmission interface). My stern
drive was Volvo. So that they could utilize existing marine engines, Volvo
made a short adapter section which mated to their transom plate design
(round rubber donut) at the back and an engine with a morse bell housing at
the front and a suitable splined shaft inside. So for me to convert to the
mazda was not very much more than unbolting the volvo and bolting in the
adapter and the mazda.
The crazy part of my change over was that I was
having difficulty locating the correct length adapter (they were made in
different lengths) and also a used one was going to be 5 or
$600.
One day I went out to my storage shed to look
at the old Volvo/Chris Craft V8 I'd bought primarily to have a spare
outdrive. Lo and behold there was the adapter I needed right on the engine.
The only change I had to make was putting some spacer's under Jon's flex
plate/damper to position it properly on the spline.
And, hey, I'm not laughing. I'd always thought
that outboards should fly.
Peter