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Speaking of weights and Al and carbon steel housings, I started to put
together a table to give me an idea of what weight to expect from a single
rotary, using the carbon steel housings.
I started with the weights given on the Aluminium housings and cast iron
housings given on a web site, but when I weighted my mix of housings I found a
discrepancy. I'm only using bathroom scales, so suspect they might be out, so
I'm hoping some one can give me some weights on cast iron housings and
crank. All the 13B cranks I had have either been cut up or thrown away. The only
remaining good crank I have is a 12 A crank.
I think Ed Anderson either quoted 160lbs or 180 lbs as an all up 2 rotor
13B weight - is that correct Ed?
The difference between the Al total weight (109lbs) and end/ IM
housings weight is a combination of crank rotors and bolts etc, I assume.
Any help appreciated.
George (down under)
Bill,
I'm in total agreement.
Just pointing it out for discussion. What I found interesting was the weight.
It's only a couple of pounds lighter than stock.
Bobby
Bobby,
There are many parts available to the drag racing crowd that are intended
for short time use. One guy even built nearly solid aluminum rotors. These
parts are like the Top Fueler engine blocks that don't even have water jackets
built into them. When you are only running the engine for less than a minute
you can get away with a lot of things. When Steve Beckham and Everett Hatch
were doing their initial experiments for their superlite engine they tried all
types of available aluminum side housings and coatings. None of them held up
long term. They tried plating, plasma spray, high alusil aluminum (Vega block
material), ceramic coatings, and several others before staying with iron
housings on the engine they intended for production. The last thing was a
built up steel housing considerably lightened from the iron versions. This was
working but the company was sold after Everett's death and wasn't developed
further. Their engines were also all p-port so they didn't bother to build in
any side ports. There used to be a bunch of people that would say that car
engines weren't up to producing 60-100% power like and aircraft engine must.
That was shown to be untrue with the rotary as it will run high Rpm's forever
IF it has good cooling and oil supply. These things are critical however, and
don't take care of themselves. Careful radiator duct design and oil cooler
duct design just must be done. The thing to remember here is that is isn't
simply making enough horsepower, that isn't too tough. The thing to remember
is that you are preparing an engine that might be running on a 500 mile long
straight-away! A great many of the car tuners realize that their engines will
rarely see operation above 20% and then only see WOT for less than a minute.
I'm an ex racer myself and can't think of one track other than Le Mans where
the car would be flat out for more than 20-30 seconds. Many aircraft operating
above 8,000 feet run WOT ALL THE TIME and just vary prop and mixture
to control power. The engine MUST have good water cooling. The engine MUST
have good oil cooling, if it is going to survive. I don't see how you are
going to achieve that with a hunk of aluminum billet and a plating job. I
would love to be proven wrong, but I won't hold my breath.
Bill Jepson
In a message dated 8/3/2010 6:03:39 PM Pacific Daylight Time,
bhughes@qnsi.net writes:
Bill,
Here's another billet center housing. Very
little info provided.
Bobby
Sorry to double up here but
while the site indicates that they have an all aluminum housing, have they
got any run time on it? I hate to be skeptical, but even the RB housings,
which certainly exist, have been holy grail level of scarcity. We need to
see some hour long 70% dyno runs on these things before we even consider
using them in an airplane.
Bill
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