kwalsh@inhale.com wrote:

What is  wrong with the Extrudehone process that it would not work just as
well for the cooling passages?

Might. Would be interesting to try.

They have a ton of different grits to choose from, it is relatively safe,
etc.  Granted it is used for porting intakes, etc, but I see no reason it
wouldn't work for the cooling passages.

As a second point, if you really want to acid etch parts, HF is the way to
go.  See your friendly neighborhood silicone wafer fab for a supply.  Don't
bother with a flint glass or metal container, though.  You'll get home will
a pool of goop....

Last, what are people seeing for installed weights (radiators, coolant,
etc) for normally aspirated 2 rotor installations anyway?  Wouldn't the
amount removed from the rotor housings amount to less than a couple
percent?

Kevin Walsh

As I recall Tracy said something like 345 pounds rads and all firewall
forward  but that was with a 28 pound motor mount which is a wee bit on 
the heavy side. The cast iron housing are in the ball park of about
100 pounds total. 25% of that would be twenty five  pounds of course.

If you have a CG problem and have to add ballast in the tail 
that 25 pounds becomes about 37 pounds over all. Every little bit helps.
A ten percent reduction over all.

Beside we are increaseing the coolant volume inside the housing for
high HP cooling applications. Water weighs 64 pounds per cubic foot as
opposed to 520 pounds per cubic foot for cast iron just in case
some smart aleck engineer gets on here and...... 

Water 0.034 pounds per cubic inch.
Cast iron 0.3 pounds per cubic inch. 

Some times you just have to reign us engineers in :-)

Paul Lamar
 
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