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Message
I’m trying
to back track and gather some info on the engine that I purchased from a
previous group member.
I'm guessing you
bought Wayne's engine, or maybe Gordon's? Both were modified by RX-7
specialties. I think I can put my hands on a set of mods that each of
these had.
I have one of the 13b’s that was (as I
was told) part of a group purchase (members of this group) from a company called
RX7 Specialties out of Canada.
I don't know of any
group purchase, but I do have one of these engines. Below is pasted from a
message that I sent someone back when I bought mine. It explains
where the engines came from.
First, Mazda will
sell brand new engines to anyone who orders at least 120. That's really
more engines than the average person can use, so these "new" engine deals are
pretty rare.
These engines
were destined to be used by the natural gas, rather than oil
business. It seems that some natural gas is contaminated, and is
called "sour gas". The best I understand, you can't avoid
getting some bad with the good. The problem is that the contaminants in
sour gas is toxic, and poisonous in high enough quantities.
The gas company must not be able to filter out the contaminant,
or it's just not feasible to do it, because they end up with a certain
quantity of sour gas that they have to get rid of. If it were up to
the gas company, they would just burn it off, but the environmentalists won't
let them do that. They're only allowed to burn off (flare) a certain
amount, and they would have to pay to have the rest disposed of. The
loophole in the rule is that it can be burned if it's being put to some
productive use. Enter the rotary. The gas company realized that
they can burn this sour gas in rotary engines, and
run generators. They use the electricity for their needs, and any
extra is sold back to the power grid. Amazingly, they turned
something they had to pay to dispose of, into something they can make money
from. To give you some idea of the scope of this, each engine is
running a 75 kva generator 24/7, and the company that's buying these engines
wants a contract to be supplied with 900 (!!!) more
engines.
Specifically, the engines are running at 3600 rpm, under a fairly
heavy load. The company used to use 454 V8 engines, but the sour
gas eats the valves up and they don't last long. For sour gas use, these rotaries are
modified for durability with ceramic apex seals, ceramic coated
rotors, and additional hardening of the rotor and side housings.
With these modifications, the engines show zero wear on the apex seals, and less
than one ten thousandth wear on the side seals, after 3000 hours of
operation. One engine ran 16,000 hours, which is about 2
years of continuous operation. Others are as high as 8000
hours, but they don't know the average hours of operation before
failure. Lest you think these engines are cared for in any
special way, realize that they run 24/7, and only stop for oil changes.
Also, they don't run oil coolers! They just run a bypass hose were
the cooler should be, and they're just sitting out in the open running...all
over the countryside.
I am especially looking for info on the
ceramic apex seals that this engine contains. I would also like to discuss the
engine with others here on the group that bought them.
I ordered my engine
"as is", so they shipped the engine without doing anything to it. I wanted
the ceramic seals, but since I was going to run a turbo, they advised
against them. They said the seals would not withstand turbo
usage. The story was that they had these ceramic seals specially
made, which is why there were so much cheaper than most. Hard to say
where they really came from.
The only problem with
these engines is that Mazda test ran them, then didn't drain the water.
After a couple years of sitting around, they form some layers of rust and crud
in the water jackets. Since yours was modified, you should be good to
go. Mine eventually got sent to Bruce Turrentine for 9.7
rotors, porting, and mods, so it got cleaned out there.
Hopefully, that helps
some.
Cheers,
Rusty (still too
windy, tomorrow should be
better)
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