Ken Welter wrote:

  I am putting together a 4 port 13b for my coot and I thought I would
show you this, I taper clearance my rotors by cutting .015 inch off
at the tip and taper it off to zero at the bluing. This stops the
tips from digging in to the side housings at high rpm and gives more
room for expansion. I am building 4 port using 12a side housings and
85 13b GSE-LE rotor housings and after dismantling three 12a's I
found they had very clean side housings as the narrower rotors expand
less. Another advantage is the 84 and 85 rotor housings are thicker
in the plug hole area as they made the later ones thinner for faster
warm up time and better emissions. The o-ring grooves are in the
aluminum housing so you do not have the problem of the cracked and
rusted lips in the cast iron ones. 12a cores cheap and plentiful
compared to 13b's and finding good side housings has been my biggest
problem in core hunting.

I might add that Ken runs nitrous oxide through his engine on a regular
basis to get his 2900 pound Coot amphibian up on the step and out of the

water.

Paul Lamar

Richard Sohn wrote:

Ken, are you willing to sell any of your good 12A rotor housings? I need at
least 3 on the long run.

Richard Sohn.
unicorn@aic-fl.com

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