Today's Message Index:
----------------------
1. 04:47 AM - Re: Engine instrumentation (n801bh@netzero.com)
2. 05:13 AM - Re: Engine instrumentation (Ed Anderson)
3. 05:48 AM - Re: Engine instrumentation (bryan green)
4. 06:11 AM - Re: Engine instrumentation (Ken)
5. 06:36 AM - Re: Engine instrumentation (Noel Loveys)
6. 06:41 AM - Re: Engine instrumentation (Gary Casey)
Message 1
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| Subject: | Re: Engine instrumentation |
I too am from the old school and I use mechanical gauges whenever I can.
If fact my whole engine panel on my 801 is mech. I also use a manifold
vacuum gauge instead of a aircraft style manifold pressure one. The vac
uum gauge is more precise and will show any problems with the motor, the
pressure gauge is dampened a bit and probably wouldn't show a slightly
stuck valve, carb ice, poor ring seating,etc... Just my opinion of cours
e...
do not archive
Ben Haas
N801BH
www.haaspowerair.com
-- "Dave Thompson" <dave.thompson@verizon.net> wrote:
While I am waiting for my 601XL kit to arrive I have been playing around
with instrument panel designs. I have done a great deal of research whi
ch has answered most of my questions. I intend to use Autometer Z-series
for engine instrumentation. They are good quality, relatively inexpensi
ve and they have all the mechanical instruments that I want. (Ironic tha
t I intend to use auto gauges for a Converted Corvair engine). I am old
fashioned. I like the idea of mechanical gauges that are not reliant on
an electrical system. I have discovered that the car guys call several
instruments differently than the aircraft guys. One example, we call it
an EGT where they call it a pyrometer.<?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" />
I intend to have:
Tachometer
Oil Temp
Oil Pressure
EGT with Left / Right switch for the two hottest cylinders
Volts
Alternator Idiot light
Hourmeter
My question to you guys is:
What is the indication on a manifold pressure gauge? Should I be looking
for a vacuum, boost or boost/vacuum gauge? As of today, there is not a
viable in flight adjustable prop available for the Corvair. Do I really
need a manifold pressure if I have a fixed pitch prop? I know about Wil
liam Wynne doing work on a fifth bearing for heaver props. When he gets
it working and available I may want to later upgrade to a constant speed
prop. Should I plan my panel for a manifold pressure gauge anyway? I ha
ve heard that it can be used with an EGT to help lean the engine on crus
e. Is that true? I plan to build basic, to the plans and get in the air.
However I will also plan for later expansion/upgrades. There will most
likely be several blanked out instrument & avionics holes in my panel wh
en I first fly. My intentions are for day VFR but I will have lights any
way.
To qualify (or disqualify) my question, I am about 25 years out of curre
ncy with 127 hours in Cessna 150, 152 and 172s. None of them had a manif
old pressure gauge so I never learned anything about them. When I get wi
thin a year or so of finishing, I plan to get current again renting a 60
1XL from the local FBO. There are two 601s within 50 miles today. I will
bet there will be more by the time I am ready.
Dave Thompson
dave.thompson@verizon.net
Partially built Corvair, 601XL on order
Do not archive
<html><P>I too am from the old school and I use mechanical gauges whenev
er I can. If fact my whole engine panel on my 801 is mech. I also
use a manifold vacuum gauge instead of a aircraft style manifold pressur
e one. The vacuum gauge is more precise and will show any problems with
the motor, the pressure gauge is dampened a bit and probably wouldn't sh
ow a slightly stuck valve, carb ice, poor ring seating,etc... Just my op
inion of course...</P>
<P>do not archive<BR><BR><BR>Ben Haas<BR>N801BH<BR>www.haaspowerair
.com<BR><BR>-- "Dave Thompson" <dave.thompson@verizon.
net> wrote:<BR></P>
<META content="Microsoft Word 11 (filtered medium)" name=Generator>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">While I am waiting for my 601XL kit to
arrive I have been playing around with instrument panel designs. I have
done a great deal of research which has answered most of my questions. I
intend to use Autometer Z-series for engine instrumentation. They are g
ood quality, relatively inexpensive and they have all the mechanical ins
truments that I want. (Ironic that I intend to use auto gauges for a Con
verted Corvair engine). I am old fashioned. I like the idea of mec
hanical gauges that are not reliant on an electrical system. I have disc
overed that the car guys call several instruments differently than the a
ircraft guys. One example, we call it an EGT where they call it a pyrome
ter.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:offic
e:office" /><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">I intend to have:<o:p></o:p></SPAN></FO
NT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">Tachometer<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">Oil Temp<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">Oil Pressure<o:p></o:p></SPAN></FONT></
P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">EGT with Left / Right switch for the tw
o hottest cylinders<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">Volts<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">Alternator Idiot light<o:p></o:p></SPAN
></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">Hourmeter<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">My question to you guys is:<o:p></o:p><
/SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">What is the indication on a manifold pr
essure gauge? Should I be looking for a vacuum, boost or boost/vacuum ga
uge? As of today, there is not a viable in flight adjustable prop availa
ble for the Corvair. Do I really need a manifold pressure if I have a fi
xed pitch prop? I know about William Wynne doing work on a fifth b
earing for heaver props. When he gets it working and available I may wan
t to later upgrade to a constant speed prop. Should I plan my panel for
a manifold pressure gauge anyway? I have heard that it can be used with
an EGT to help lean the engine on cruse. Is that true? I plan to build b
asic, to the plans and get in the air. However I will also plan for late
r expansion/upgrades. There will most likely be several blanked out inst
rument & avionics holes in my panel when I first fly. My intentions
are for day VFR but I will have lights anyway.<o:p></o:p></SPAN></FONT><
/P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier">To qualify (or disqualify) my question,
I am about 25 years out of currency with 127 hours in Cessna 150, 152 a
nd 172s. None of them had a manifold pressure gauge so I never learned a
nything about them. When I get within a year or so of finishing, I plan
to get current again renting a 601XL from the local FBO. There are two 6
01s within 50 miles today. I will bet there will be more by the time I a
m ready.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoAutoSig><FONT face=Courier size=2><SPAN style="FONT-
SIZE: 10pt; FONT-FAMILY: Courier">Dave Thompson<o:p></o:p></SPAN></FONT>
</P>
<P class=MsoAutoSig><FONT face=Courier size=2><SPAN style="FONT-
SIZE: 10pt; FONT-FAMILY: Courier"><A href="mailto:dave.thompson@verizo
n.net">dave.thompson@verizon.net</A><o:p></o:p></SPAN></FONT></P>
<P class=MsoAutoSig><FONT face=Courier size=2><SPAN style="FONT-
SIZE: 10pt; FONT-FAMILY: Courier">Partially built Corvair, 601XL on orde
r<o:p></o:p></SPAN></FONT></P>
<P class=MsoAutoSig><FONT face=Courier size=2><SPAN style="FONT-
SIZE: 10pt; FONT-FAMILY: Courier">Do not archive<o:p></o:p></SPAN></FONT
></P>
<P class=MsoNormal><FONT face=Courier size=2><SPAN style="FONT-S
IZE: 10pt; FONT-FAMILY: Courier"><o:p> </o:p></SPAN></FONT></P></DI
V></html>
Message 2
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| Subject: | Re: Engine instrumentation |
Hi Dave,
I have flown my RV-6A powered with a Mazda Rotary engine and a fixed
pitch prop. Not a corvair (good engine by the way), but perhaps my
experience and view points may help.
I have found 5 engine performance instruments that I consider very
useful in fine tuning for maximum performance as well as trouble
shooting.
1. RPM - pretty much goes without saying that you need one
2. Fuel Flow Meter (a good indicator of the amount fuel you are burning
and therefore the power you are producing)
3. Air/Fuel Ratio Indicator (immediately tells you whether your engine
is operating in the lean (less power more economy) or the rich (more
power, less economy) region.
4. Manifold pressure gauge (you can use a vacuum gauge - but almost all
flyers and reference to engine use manifold pressure with 29.92 inches
of Mercury being the manifold pressure when the throttle is wide open or
in other words - atmospheric pressure at sea level on a standard 59F
day)
5. EGT Gauge (Useful depending on how many and where they are
located. Slowest of the instruments to indicate the engine's state, but
can show cylinders that are running lean/rich) and can aid in tuning -
particularly if you don't have the full set of instruments above).
Here's my case for manifold pressure. Unless you can measure your
manifold pressure - you really do not know how well (or bad) your
induction system is functioning. For example, if you have a lossless
induction system (no pressure drop along it anywhere) then you should
see 29.92 " Hg with WOT (at sea level standard day). If you are only
seeing say 26 " Hg then you are losing close to 4" of manifold pressure.
That means you are getting less air into your engine and therefore
producing less power. Without the manifold pressure gauge, you might
know you are producing less than expected power, but you would not know
the reason. Perhaps your throttle cable slipped and your throttle plate
is not fully open, perhaps a crimp in your air intake hose (if you use
one) restricting airflow, perhaps you have a air filter in need of
cleaning, etc. This I think is worth knowing.
My 0.02 worth
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
----- Original Message -----
From: Dave Thompson
To: engines-list@roxy.matronics.com
Sent: Saturday, June 17, 2006 1:11 AM
Subject: Engines-List: Engine instrumentation
While I am waiting for my 601XL kit to arrive I have been playing
around with instrument panel designs. I have done a great deal of
research which has answered most of my questions. I intend to use
Autometer Z-series for engine instrumentation. They are good quality,
relatively inexpensive and they have all the mechanical instruments that
I want. (Ironic that I intend to use auto gauges for a Converted Corvair
engine). I am old fashioned. I like the idea of mechanical gauges that
are not reliant on an electrical system. I have discovered that the car
guys call several instruments differently than the aircraft guys. One
example, we call it an EGT where they call it a pyrometer.
I intend to have:
Tachometer
Oil Temp
Oil Pressure
EGT with Left / Right switch for the two hottest cylinders
Volts
Alternator Idiot light
Hourmeter
My question to you guys is:
What is the indication on a manifold pressure gauge? Should I be
looking for a vacuum, boost or boost/vacuum gauge? As of today, there is
not a viable in flight adjustable prop available for the Corvair. Do I
really need a manifold pressure if I have a fixed pitch prop? I know
about William Wynne doing work on a fifth bearing for heaver props. When
he gets it working and available I may want to later upgrade to a
constant speed prop. Should I plan my panel for a manifold pressure
gauge anyway? I have heard that it can be used with an EGT to help lean
the engine on cruse. Is that true? I plan to build basic, to the plans
and get in the air. However I will also plan for later
expansion/upgrades. There will most likely be several blanked out
instrument & avionics holes in my panel when I first fly. My intentions
are for day VFR but I will have lights anyway.
To qualify (or disqualify) my question, I am about 25 years out of
currency with 127 hours in Cessna 150, 152 and 172s. None of them had a
manifold pressure gauge so I never learned anything about them. When I
get within a year or so of finishing, I plan to get current again
renting a 601XL from the local FBO. There are two 601s within 50 miles
today. I will bet there will be more by the time I am ready.
Dave Thompson
dave.thompson@verizon.net
Partially built Corvair, 601XL on order
Do not archive
Message 3
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| Subject: | Re: Engine instrumentation |
A manifold pressure gauge is used with boosted engines, so if you
are not using a turbocharger or supercharger it would not be useful to
you. On normally aspirated engines the manifold works under vacuum not
pressure ,so you would want a vacuum gauge.
Bryan Green (Elgin SC)
Sonex #929
While I am waiting for my 601XL kit to arrive I have been playing
around with instrument panel designs. I have done a great deal of
research which has answered most of my questions. I intend to use
Autometer Z-series for engine instrumentation. They are good quality,
relatively inexpensive and they have all the mechanical instruments that
I want. (Ironic that I intend to use auto gauges for a Converted Corvair
engine). I am old fashioned. I like the idea of mechanical gauges that
are not reliant on an electrical system. I have discovered that the car
guys call several instruments differently than the aircraft guys. One
example, we call it an EGT where they call it a pyrometer.
I intend to have:
Tachometer
Oil Temp
Oil Pressure
EGT with Left / Right switch for the two hottest cylinders
Volts
Alternator Idiot light
Hourmeter
My question to you guys is:
What is the indication on a manifold pressure gauge? Should I be
looking for a vacuum, boost or boost/vacuum gauge? As of today, there is
not a viable in flight adjustable prop available for the Corvair. Do I
really need a manifold pressure if I have a fixed pitch prop? I know
about William Wynne doing work on a fifth bearing for heaver props. When
he gets it working and available I may want to later upgrade to a
constant speed prop. Should I plan my panel for a manifold pressure
gauge anyway? I have heard that it can be used with an EGT to help lean
the engine on cruse. Is that true? I plan to build basic, to the plans
and get in the air. However I will also plan for later
expansion/upgrades. There will most likely be several blanked out
instrument & avionics holes in my panel when I first fly. My intentions
are for day VFR but I will have lights anyway.
To qualify (or disqualify) my question, I am about 25 years out of
currency with 127 hours in Cessna 150, 152 and 172s. None of them had a
manifold pressure gauge so I never learned anything about them. When I
get within a year or so of finishing, I plan to get current again
renting a 601XL from the local FBO. There are two 601s within 50 miles
today. I will bet there will be more by the time I am ready.
Dave Thompson
dave.thompson@verizon.net
Partially built Corvair, 601XL on order
Do not archive
Message 4
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| Subject: | Re: Engine instrumentation |
--> Engines-List message posted by: Ken <klehman@albedo.net>
Hello Dave
A boost or boost/vacuum gauge is required for a turbo or supercharged
engine only. You don't want that on a normally aspirated engine as it
would just compress the part of the scale that will be of use to you.
A vacuum or manifold pressure gauge would be required with a constant
speed or in flight variable pitch prop. Some controllers for electric
variable pitch props might well display manifold pressure by the time
you purchase or construct such a thing. I left blank panel space near
the tach for one such device.
With a manifold pressure guage reading absolute pressure and a
tachometer, you can make a little chart that will approximate you how
much power you are producing. You can't easilly do that with a vacuum
gauge as it references to ambient pressure and the chart would need a
separate page for every different pressure altitude. So I'd suggest that
the manifold pressure guage is more useful than an automotive vacuum
gauge if you have the choice. Neither is required with a nomally
aspirated engine and a fixed pitch prop. Not having one may keep your
eyes outside more which can be a good thing.
If it weren't for the expense I'd prefer fuel flow over manifold pressure.
EGT's are nice if you have a manual mixture control or if you must tune
the mixture. A pressure guage won't help with leaning from what I've seen.
Ken
Dave Thompson wrote:
> While I am waiting for my 601XL kit to arrive I have been playing
> around with instrument panel designs. I have done a great deal of
> research which has answered most of my questions. I intend to use
> Autometer Z-series for engine instrumentation. They are good quality,
> relatively inexpensive and they have all the mechanical instruments
> that I want. (Ironic that I intend to use auto gauges for a Converted
> Corvair engine). I am old fashioned. I like the idea of mechanical
> gauges that are not reliant on an electrical system. I have discovered
> that the car guys call several instruments differently than the
> aircraft guys. One example, we call it an EGT where they call it a
> pyrometer.
>
>
>
> I intend to have:
>
>
>
> Tachometer
>
> Oil Temp
>
> Oil Pressure
>
> EGT with Left / Right switch for the two hottest cylinders
>
> Volts
>
> Alternator Idiot light
>
> Hourmeter
>
>
>
> My question to you guys is:
>
>
>
> What is the indication on a manifold pressure gauge? Should I be
> looking for a vacuum, boost or boost/vacuum gauge? As of today, there
> is not a viable in flight adjustable prop available for the Corvair.
> Do I really need a manifold pressure if I have a fixed pitch prop? I
> know about William Wynne doing work on a fifth bearing for heaver
> props. When he gets it working and available I may want to later
> upgrade to a constant speed prop. Should I plan my panel for a
> manifold pressure gauge anyway? I have heard that it can be used with
> an EGT to help lean the engine on cruse. Is that true? I plan to build
> basic, to the plans and get in the air. However I will also plan for
> later expansion/upgrades. There will most likely be several blanked
> out instrument & avionics holes in my panel when I first fly. My
> intentions are for day VFR but I will have lights anyway.
>
>
>
> To qualify (or disqualify) my question, I am about 25 years out of
> currency with 127 hours in Cessna 150, 152 and 172s. None of them had
> a manifold pressure gauge so I never learned anything about them. When
> I get within a year or so of finishing, I plan to get current again
> renting a 601XL from the local FBO. There are two 601s within 50 miles
> today. I will bet there will be more by the time I am ready.
>
>
>
> Dave Thompson
>
> dave.thompson@verizon.net <mailto:dave.thompson@verizon.net>
>
> Partially built Corvair, 601XL on order
>
> Do not archive
>
>
>
Message 5
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| Subject: | Engine instrumentation |
I don't know if I'm old school.... there are days I just feel
old...only
joking.
I think the real advantage to electronic instruments is weight saving.
All
my instruments are steam driven but in my small panel there isn't room
for
much else and I wouldn't fly without mechanical backup.
do not archive
Noel
-----Original Message-----
[mailto:owner-engines-list-server@matronics.com] On Behalf Of
n801bh@netzero.com
Sent: Saturday, June 17, 2006 9:10 AM
I too am from the old school and I use mechanical gauges whenever I can.
If
fact my whole engine panel on my 801 is mech. I also use a manifold
vacuum
gauge instead of a aircraft style manifold pressure one. The vacuum
gauge is
more precise and will show any problems with the motor, the pressure
gauge
is dampened a bit and probably wouldn't show a slightly stuck valve,
carb
ice, poor ring seating,etc... Just my opinion of course...
do not archive
Ben Haas
N801BH
www.haaspowerair.com
-- "Dave Thompson" <dave.thompson@verizon.net> wrote:
While I am waiting for my 601XL kit to arrive I have been playing around
with instrument panel designs. I have done a great deal of research
which
has answered most of my questions. I intend to use Autometer Z-series
for
engine instrumentation. They are good quality, relatively inexpensive
and
they have all the mechanical instruments that I want. (Ironic that I
intend
to use auto gauges for a Converted Corvair engine). I am old fashioned.
I
like the idea of mechanical gauges that are not reliant on an electrical
system. I have discovered that the car guys call several instruments
differently than the aircraft guys. One example, we call it an EGT where
they call it a pyrometer.
I intend to have:
Tachometer
Oil Temp
Oil Pressure
EGT with Left / Right switch for the two hottest cylinders
Volts
Alternator Idiot light
Hourmeter
My question to you guys is:
What is the indication on a manifold pressure gauge? Should I be looking
for
a vacuum, boost or boost/vacuum gauge? As of today, there is not a
viable in
flight adjustable prop available for the Corvair. Do I really need a
manifold pressure if I have a fixed pitch prop? I know about William
Wynne
doing work on a fifth bearing for heaver props. When he gets it working
and
available I may want to later upgrade to a constant speed prop. Should I
plan my panel for a manifold pressure gauge anyway? I have heard that it
can
be used with an EGT to help lean the engine on cruse. Is that true? I
plan
to build basic, to the plans and get in the air. However I will also
plan
for later expansion/upgrades. There will most likely be several blanked
out
instrument & avionics holes in my panel when I first fly. My intentions
are
for day VFR but I will have lights anyway.
To qualify (or disqualify) my question, I am about 25 years out of
currency
with 127 hours in Cessna 150, 152 and 172s. None of them had a manifold
pressure gauge so I never learned anything about them. When I get within
a
year or so of finishing, I plan to get current again renting a 601XL
from
the local FBO. There are two 601s within 50 miles today. I will bet
there
will be more by the time I am ready.
Dave Thompson
dave.thompson@verizon.net
Partially built Corvair, 601XL on order
Do not archive
Message 6
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| Subject: | Re: Engine instrumentation |
--> Engines-List message posted by: Gary Casey <glcasey@adelphia.net>
> I suggest that if you will be running a fixed-pitch prop you forget
> about a manifold pressure gage. You will control the power
> primarily by throttling to get the rpm you want,not by looking at a
> manifold pressure gage. It might be interesting and possibly
> informative, but it will add weight and complexity for very little
> benefit. If you do decide to add the gage, an automotive vacuum or
> "boost" gage is not what you want - you need to measure Manifold
> ABSOLUTE Pressure (MAP), not pressure relative to atmosphere.
> Autometer might sell a true MAP gage, but I doubt it. I generally
> agree with your choice of instruments, but I would add an oil
> pressure light as you should have immediate warning of low oil
> pressure. Hobbs sells an oil pressure switch that has two sets of
> contacts, one to turn the Hobbs meter on with oil pressure and one
> to turn the light on without it.
Gary Casey
> Time: 10:16:48 PM PST US
> From: "Dave Thompson" <dave.thompson@verizon.net>
> Subject: Engines-List: Engine instrumentation
>
> While I am waiting for my 601XL kit to arrive I have been playing
> around
> with instrument panel designs. I have done a great deal of research
> which
> has answered most of my questions. I intend to use Autometer Z-
> series for
> engine instrumentation. They are good quality, relatively
> inexpensive and
> they have all the mechanical instruments that I want. (Ironic that
> I intend
> to use auto gauges for a Converted Corvair engine). I am old
> fashioned. I
> like the idea of mechanical gauges that are not reliant on an
> electrical
> system. I have discovered that the car guys call several instruments
> differently than the aircraft guys. One example, we call it an EGT
> where
> they call it a pyrometer.
>
>
> I intend to have:
>
>
> Tachometer
>
> Oil Temp
>
> Oil Pressure
>
> EGT with Left / Right switch for the two hottest cylinders
>
> Volts
>
> Alternator Idiot light
>
> Hourmeter
>
>
> My question to you guys is:
>
>
> What is the indication on a manifold pressure gauge? Should I be
> looking for
> a vacuum, boost or boost/vacuum gauge? As of today, there is not a
> viable in
> flight adjustable prop available for the Corvair. Do I really need a
> manifold pressure if I have a fixed pitch prop? I know about
> William Wynne
> doing work on a fifth bearing for heaver props. When he gets it
> working and
> available I may want to later upgrade to a constant speed prop.
> Should I
> plan my panel for a manifold pressure gauge anyway? I have heard
> that it can
> be used with an EGT to help lean the engine on cruse. Is that true?
> I plan
> to build basic, to the plans and get in the air. However I will
> also plan
> for later expansion/upgrades. There will most likely be several
> blanked out
> instrument & avionics holes in my panel when I first fly. My
> intentions are
> for day VFR but I will have lights anyway.
>
>
> To qualify (or disqualify) my question, I am about 25 years out of
> currency
> with 127 hours in Cessna 150, 152 and 172s. None of them had a
> manifold
> pressure gauge so I never learned anything about them. When I get
> within a
> year or so of finishing, I plan to get current again renting a
> 601XL from
> the local FBO. There are two 601s within 50 miles today. I will bet
> there
> will be more by the time I am ready.
>
>
> Dave Thompson
>
> dave.thompson@verizon.net
>
> Partially built Corvair, 601XL on order
>
> Do not archive
>
>
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