I stopped off in Michigan and met C. Smith at
his hangar. He is building a P-port rotary powered Zenith 601.
Here is a shot of his square tube exhaust manifold.
This will be the start of a tangential muffler.
Note the English wheel. Brian Trubee will not have the
only aluminum cowl :)
C. Smith came up with some cute Minihelc pressure gages.
These are super sensitive at only 2 inches of water full scale.
I was unaware they made them this small.

Paul Lamar


   No way dude that is twice the HP and twice the weight than what
that plane is made for and it will take a 50lb chunk of lead in the
tail to put it in balance, I am building Zenith 601 and I have
1500hrs flying time in my rotary coot but for the Zenith I am just
going to bolt on a 0-200 and go fly as I am done experimenting.
  Ken

I made a mistake Ken. It is a 605.

Let us know how that O-200 works out for you :)
I'll bet you won't see 1500 hours with out some
valve work. I think I only average 500 hours with
out some valve work on my O-470. Of course I cannot legally
do the work myself so it gets expensive.

Paul Lamar

  The point is that its the wrong engine for that plane or the wrong
plane for that engine now build a 801 Zenith that will work,  friend
of mine built a 601 and put a 235 Lycoming in it and he had to put a
lead weight in the tail so without a doubt it will be a single place
plane 235 will push it over red line so what do you need a freeking P
port 13b for.
 Ken

No Ken not a 601. A CH 640. I finally have it right.

They are entirely different aircraft apparently.
Their numbering system sucks IMHO. Confusing to say the least.

I agree. The 601 whatever that is sounds like an LSA.
The two rotor is too heavy.

C. Smith what is the VNE on the CH 640?

Paul Lamar