>>> Here's a link to a fairly long thread:
>>>
>>>
http://canardaviationforum.dmt.net/showthread.php?t=2058&page=5&pp=15
<http://canardaviationforum.dmt.net/showthread.php?t=2058&page=5&pp=15>
>>>
>>>
>>>
>>> I have no idea what is going on Matt. According to
Francois
>>> the unburned hydrocarbons are burning in the exhaust
>>> manifold and or the turbo. Perhaps the RX8 engine might
>>> be a better choice as it supposedly recycles unburned fuel
>>> with a cooler exhaust. Francois is doing some turbine
blade
>>> temperature test by painting the turbine blades with
special
>>> paint.
>>>
>>> To really know what is going on the intake air temp should
>>> be monitored and the engine leaned over a wide range
measuring
>>> the mixture ratio with a wide band mixture monitor to see
>>> what effect this has on TIT. In other words get data on
>>> TIT verses mixture ratio. Could be when leaned properly
>>> with a a cool intake charge to discourage detonation or
>>> even anti detonation fluid injected the data
>>> will show the TIT coming down with a leaned mixture.
>>>
>>> On the other hand 1800 F may be no problem for an Inconel
>>> turbine at modest RPMs. Does John have an Inconel turbine?
>>> One needs to know the RPM of the turbine as that has a
serious
>>> affect on the life of a turbine blade due to
centrifugal force.
>>>
>>> Paul Lamar ...No rotor no motor.
>>
>>
>>
>> Hi Matt, where's your EGT probe mounted?
>>
>> B
>
> Brian, according to John's post about this turbo, about
which
Matt was
> questioning, John's EGT probe is mounted in the exhaust
pipe 2
inches
> after
> the turbine.
>
> Barry Gardner
> Wheaton, IL
1700*F at 2-3" past the turbine housing is far, far too
hot. Just to
give
you guys
an idea of what I do, I shoot for mid 1400's and nothing
higher on very
heavy
loads that go into the several hundreds of horsepower
range. My next
question:
What kind of manifold pressure are you running on take-off
John? At that
manifold pressure, what's the amount of advance you're
cranking out
of the
computer for the leading plugs and then the trail-split
timing advance?
Also, do you guys monitor air/fuel ratios using a 5V
wideband lambda
sensor
setup?
B
___________________________________________________________________________
Brian D. Cain -/- Dallas/Ft. Worth, TX -/-
bdc@bdcmotorsports.com <mailto:bdc@bdcmotorsports.com>
BDC Motorsports | Performance Rotary Engines, Specialized
Porting, EFI
System Installation & Tuning
MSN
bdc196@hotmail.com <mailto:bdc196@hotmail.com>, Yahoo!
bdc196, AOL Symajhi, ICQ# 1733105
http://www.bdcmotorsports.com -/-
http://bdc.cyberosity.com
If this turns into a really tough problem...
Is there any chance that an
_axial_ flow turbine could be designed
such that a portion of the wheel (like half to 2/3rd) is blown with
hot exhaust, but the remaining portion draws cool air? It might be
possible to significantly reduce the average temperature that the
wheel sees this way. One downside of this arrangement is that the
wheel will see very assymetrical loads - the side exposed to the
exhaust would be forced one direction, but the side pulling cool air
would be forced the opposite direction. I suppose that if you feed
cool air in on two sides of the wheel, the forces could be balanced..
Or how about cool air injection? It would have to be fairly high
pressure - a good trick, cool, high pressure air. But it only has
to be relatively cool - to lower the temp of the wheel.
A plot of EGT vs ignition advance vs mixture would be interesting.
More stuff to do on a dyno.
Regards,
Matt-
And, PV=nRT says that a bigger turbine will reduce temps... Though the
delta-P across the wheel is lower, which shouldn't be a problem as long
as the turbine's larger diamter yields higher torque.
Matt-
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