Took about 2-3 hours per housing. Dremel tool, abrasive disk,
sanding drum, coarse and fine cratex wheels. Checked for
interference with starret machinists scale.

C. Smith

A Dremel tool is a bit under powered :)

Paul Lamar

Hmmm. Not sure what you mean by that. I'll say this, the dremel
never got away from me and nicked the liner anywhere I didn't want
it to. Die grinders, and other high speed pneumatic rotary tools do
that to me all the time. 8-O
C. Smith

I have watched a pro do it. John at Mazdatrix. In his 40 years
working with rotaries he has probably ported a thousand end housings
:) He makes a wood clamp to securely hold the rotor housing and then
uses two hands on the die grinder. Takes him 15 minutes :) The other
secret is you use grinding stones and those sandpaper wrapped
sanding drums. Less "catching" than a bur.

Paul Lamar


Another tip I have found is to use light pressure. Let the burr or stone and
the speed do the work rather than leaning on the grinder to make it go faster.
It is called finesse. You found out it works on women years ago.

Dale Davies


First of all, I do not have the benefit of having 40 years of experience with
rotaries and porting thousands of housings. My experience prior to this was
zero. Nor do I have the luxury of unlimited finances. My investment so far in
each housing at this point is somewhere around $500. I cannot afford a mistake.
Therefore I chose to proceed with great care and caution. I used a lot of
finess, perhaps why it took 8 to 12 times longer than the professional with 40
years of experience, and I always use 2 hands on my rotary tools.

I used the tools and materials I had at hand, my hangar is currently about 11
degrees F which is where my compressor is, another reason I used a dremel. In
spite of my lack of professionalism, I was successful in that I believe the seals will make it past the port without being damaged or excessive wear. In that respect, I am quite satisfied that the time and effort was worth it.
Your results may vary.
C. Smith

11 F heck? I would not have been there C :)
I would be home by the heater. I am too old for that.
That shows real dedication.

Paul Lamar