Mike,
There are several issues to be concerned with on the all aluminum
intermediate housings. (yes those)
First: The coatings are fabulously expensive. They are so hard that they
must be diamond lapped. Lastly if they aren't perfectly applied they can flake
and destroy the engine. On the 20B there are studs that are threaded into the
housing, (the thick one), which is much tougher to make safe in aluminum. Our
point is that we have a way to make the same intermediate housings out of steel,
with only a 1 pound penalty over the aluminum housings. They will be MUCH
cheaper than aluminum and have none of the coating drawbacks because they will
be gas nitrided just like the standard irons. I believe it was figured one time
that an all aluminum engine in a 13B would save 27 pounds. If that was correct
the savings with the special steel plates would be 24 pounds with none of the
drawbacks. Yes, the plan for any parts we make will be to make them compatible
with the standard mazda engine other than P-porting. One of the problems noted
in making all the housings aluminum other than cost has been collapse (minor) of
the intermediate housings due to heat cycling. There is nothing wrong with
good aluminum housing other than the fact that they cost about 2500-3000 dollars
EACH. The steel housings would be more like that for all 3 and no flaking even
possible.
Bill Jepson
In a message dated 4/20/2010 7:23:23 PM Pacific Daylight Time,
rv-4mike@cox.net writes:
Bill,
You mention "steel side plates that will weigh
1 pound more than the aluminum side plates...." Are you talking about the 3
intermediate iron housings? If not, what are you talking about?
What is it that makes replicating the iron
housings in aluminum so difficult? I realize there is a potential wear
issue, but is there no relatively inexpensive means to produce these housings
with a hardened or treated wear surface that will survive while otherwise
replicating the stock configuration?
Seems to me that the hot ticket would be a PP
configured engine with all aluminum housings, but otherwise standard
Mazda configuration so that it would be plug and play compatible with the
stock engine and would use standard available parts (like Tracy's PSRU). That
is an engine I'd pay good money for and would seem to hit the sweet spot in
providing potentially more power with less weight than the typical 4
cylinder Lyc, without all of the budget busting unobtanium of the
original Superlight engine. And I think that is what Brian is getting at. No
coincidence that both of us have overweight RV-4s and would like to take some
weight off. What am I missing?
Mike Wills