Question about auto gas STC

[JimT96309]

I am currently interested in an older C-172 (Cont. 0-300 engine) that has an
STC for auto gas. My questions are:

1. Can I continue to use AVgas instead of auto fuel?

2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
to get out lightly loaded (me and one in the right seat) at a density altitude
of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
difference would I see with the 15 fewer horses up front?

3. Can you give me a rough idea of cost to add a 2nd Nav-comm with Glideslope
and then have the whole thing certified for IFR? I would probably try to find a
good quality used one from one of the local shops.

Thanks for any help you can give to a rookie getting ready to make a first
purchase.

Jim

[Orval Fairbairn]

In article >,
(JimT96309) wrote:

> I am currently interested in an older C-172 (Cont. 0-300 engine) that has an
> STC for auto gas. My questions are:
>
> 1. Can I continue to use AVgas instead of auto fuel?

Yes -- the STC allows mixing and switching back and forth.



> 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been
> able
> to get out lightly loaded (me and one in the right seat) at a density
> altitude
> of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
> difference would I see with the 15 fewer horses up front?


How do you get 15 fewer horses? You may actually get a few more with
mogas.


> 3. Can you give me a rough idea of cost to add a 2nd Nav-comm with
> Glideslope
> and then have the whole thing certified for IFR? I would probably try to find
> a
> good quality used one from one of the local shops.


I can't help you there. Check with some reputable avionics shops.

[Newps]

"Orval Fairbairn" > wrote in message
...
> > 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've
been
> > able
> > to get out lightly loaded (me and one in the right seat) at a density
> > altitude
> > of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp.
What
> > difference would I see with the 15 fewer horses up front?
>
>
> How do you get 15 fewer horses? You may actually get a few more with
> mogas.

His has 15 fewer than the clubs 172 with the O320. The O300 bird won't
perform as well unless it is lighter.

[JimT96309]

>How do you get 15 fewer horses? You may actually get a few more with
>mogas.

It is my understanding that the 0-300 is only rated at 145 hp.

[zatatime]

On 02 Jun 2004 01:52:19 GMT, (JimT96309) wrote:

>I am currently interested in an older C-172 (Cont. 0-300 engine) that has an
>STC for auto gas. My questions are:
>
>1. Can I continue to use AVgas instead of auto fuel?

Yes.
>
>2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
>to get out lightly loaded (me and one in the right seat) at a density altitude
>of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
>difference would I see with the 15 fewer horses up front?
>
172s with the 0-300 were also made with a different wing design. It
is not a "high lift wing" like you are used to. You will not get the
same take-off performance out of it.

>3. Can you give me a rough idea of cost to add a 2nd Nav-comm with Glideslope
>and then have the whole thing certified for IFR? I would probably try to find a
>good quality used one from one of the local shops.

Figure 5 grand and you might be happy when you get the bill.
>
>Thanks for any help you can give to a rookie getting ready to make a first
>purchase.
>

Don't know if you're partial to 172s for any reason, but you may want
to open up the search to other aircraft. Piper and Grumman may offer
you something with suitable performance and a slightly less expensive
purchase price. Obviously this opens up a whole bunch of other
questions you need to answer for yourself, but if high altitude ops
are your primary concern I thought it worth mentioning.

>Jim
>


Good Luck!!

z

[Dan Truesdell]

That is correct. I believe the 145 HP O-300 was replaced by the
Lycoming 150HP O-320 around '68. We had an O-300 in ours and decided
to replace it with a O-360 (180 HP). Glad we did. Continental doesn't
make the O-300 any more, and the extra 35 HP is great. It's a little
expensive (somewhere around $32K) but you get a factory new engine. I
love having the extra power and getting to keep the manual 40 degree
flaps. (Ours is a '64 E model.)

JimT96309 wrote:
>>How do you get 15 fewer horses? You may actually get a few more with
>>mogas.
>
>
> It is my understanding that the 0-300 is only rated at 145 hp.


--
Remove "2PLANES" to reply.

[TTA Cherokee Driver]

JimT96309 wrote:


> 3. Can you give me a rough idea of cost to add a 2nd Nav-comm with Glideslope
> and then have the whole thing certified for IFR? I would probably try to find a
> good quality used one from one of the local shops.

Conventional wisdom (I am not an owner so do not know) is that it's more
economical to spend the money to get a plane that already has the
avionics you want, rather than buy low and try to upgrade. Not to
mention the downtime in the avionics shop, are you buying it to fly it
or to park it in the shop?

[Jim Weir]

(JimT96309)
shared these priceless pearls of wisdom:

->I am currently interested in an older C-172 (Cont. 0-300 engine) that has an
->STC for auto gas. My questions are:
->
->1. Can I continue to use AVgas instead of auto fuel?

Yes. You can mix and match all you want.


->
->2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
->to get out lightly loaded (me and one in the right seat) at a density altitude
->of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
->difference would I see with the 15 fewer horses up front?

I took our 172 (64 E model) in and out of Big Bear several dozen times over the
years. You just learn not to do it between 10 am and 7 pm. Not a big deal.


->
->3. Can you give me a rough idea of cost to add a 2nd Nav-comm with Glideslope
->and then have the whole thing certified for IFR? I would probably try to find
a
->good quality used one from one of the local shops.

The best thing about an older aircraft is that you can learn to work on it
yourself without a lot of hassle. A second navcom with GS can be had on Ebay
for $700 or so. Two weeks of your work will install it AND give you a hell of
an insight into the internal workings of your aircraft.

What does "certified for IFR" mean? Find me an FAR reference.


->
->Thanks for any help you can give to a rookie getting ready to make a first
->purchase.
->
->Jim
->


Jim

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

[TripFarmer]

I too have a STC for autofuel. You should read up on using it and
leaning using autofuel. Autofuel has different properties than 100LL.


Trip




In article >, says...
>
>I am currently interested in an older C-172 (Cont. 0-300 engine) that has an
>STC for auto gas. My questions are:
>
>1. Can I continue to use AVgas instead of auto fuel?
>
>2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
>to get out lightly loaded (me and one in the right seat) at a density altitude
>of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
>difference would I see with the 15 fewer horses up front?
>
>3. Can you give me a rough idea of cost to add a 2nd Nav-comm with Glideslope
>and then have the whole thing certified for IFR? I would probably try to find a
>good quality used one from one of the local shops.
>
>Thanks for any help you can give to a rookie getting ready to make a first
>purchase.
>
>Jim
>
>

[Robert M. Gary]

(JimT96309) wrote in message >...
> I am currently interested in an older C-172 (Cont. 0-300 engine) that has an
> STC for auto gas. My questions are:
>
> 1. Can I continue to use AVgas instead of auto fuel?
>
> 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
> to get out lightly loaded (me and one in the right seat) at a density altitude
> of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
> difference would I see with the 15 fewer horses up front?

I'm not 100% sure about the Big Bear area, but in most parts of
California the FAA prohibits the use of autogas. Autogas in Ca usually
(depending on the county) contains MTBE which is prohibited by the FAA
because it eats fuel lines.

-Robert

[MikeM]

Robert M. Gary wrote:

>
> I'm not 100% sure about the Big Bear area, but in most parts of
> California the FAA prohibits the use of autogas. Autogas in Ca usually
> (depending on the county) contains MTBE which is prohibited by the FAA
> because it eats fuel lines.
>
> -Robert

MTBE is ok

http://www.avweb.com/news/maint/187232-1.html


You may be thinking of alcohol additives, which are precluded by
my STC and the FAA.

MikeM

[Rosspilot]

> We had an O-300 in ours and decided
>to replace it with a O-360 (180 HP). Glad we did. Continental doesn't
>make the O-300 any more, and the extra 35 HP is great. It's a little
>expensive (somewhere around $32K) but you get a factory new engine. I
>love having the extra power and getting to keep the manual 40 degree
>flaps. (Ours is a '64 E model.)

I have a '67 and when the time comes, I will probably upgrade to the 180 hp.
How much more fuel do you burn now? Did you install any new fuel tanks or do
you still carry 36 gallons?

I was up today for 1.8 and burned only 14 gallons of mogas. :-)



www.Rosspilot.com

[[email protected]]

Jim Weir > wrote:
: What does "certified for IFR" mean? Find me an FAR reference.

Exactly... the only "certification" requirement for IFR is a 24 month
altimeter static check in addition to the *required* 24-month VFR transponder encoder
check. Now that I know more about it, using "IFR certified" in an sale advertisement
can be pretty much bull.

Now, whether or not it's a good idea to have the equipment checked before
slogging in the soup is another matter. My experience has been 85% of avionics
failures is due to mis-wiring, or poor installation and loose/broken wiring. Another
10% is broken wire/solder joint inside the radio. Probably only 5% is actually broken
component in the radio.

-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[zatatime]

On 02 Jun 2004 19:55:40 GMT, (Rosspilot)
wrote:

>> We had an O-300 in ours and decided
>>to replace it with a O-360 (180 HP). Glad we did. Continental doesn't
>>make the O-300 any more, and the extra 35 HP is great. It's a little
>>expensive (somewhere around $32K) but you get a factory new engine. I
>>love having the extra power and getting to keep the manual 40 degree
>>flaps. (Ours is a '64 E model.)
>
>I have a '67 and when the time comes, I will probably upgrade to the 180 hp.
>How much more fuel do you burn now? Did you install any new fuel tanks or do
>you still carry 36 gallons?
>
> I was up today for 1.8 and burned only 14 gallons of mogas. :-)
>
>
>
>www.Rosspilot.com
>


As a rule of thumb you can use a half a pound per horse power per
hour.

i.e. 75% power of a 160hp engine is 120hp, so .5*120 = 60lbs per
hour, or 10 gallons an hour in cruise. How you lean, and other things
obviously modify this number somewhat, but it's a good rule of thumb.

HTH.
z

[Martin Kosina]

> >2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
> >to get out lightly loaded (me and one in the right seat) at a density altitude
> >of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
> >difference would I see with the 15 fewer horses up front?

> Don't know if you're partial to 172s for any reason, but you may want
> to open up the search to other aircraft. Piper and Grumman may offer
> you something with suitable performance and a slightly less expensive
> purchase price.

Are <180hp (less expensive ^ ) Grumman's really suitable for frequent
8000+' DA takeoffs ?

[Newps]

"Martin Kosina" > wrote in message
om...
>
> Are <180hp (less expensive ^ ) Grumman's really suitable for frequent
> 8000+' DA takeoffs ?


They are suitable for one attempt.

[zatatime]

On 2 Jun 2004 14:06:56 -0700, (Martin
Kosina) wrote:

>> >2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been able
>> >to get out lightly loaded (me and one in the right seat) at a density altitude
>> >of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp. What
>> >difference would I see with the 15 fewer horses up front?
>
>> Don't know if you're partial to 172s for any reason, but you may want
>> to open up the search to other aircraft. Piper and Grumman may offer
>> you something with suitable performance and a slightly less expensive
>> purchase price.
>
>Are <180hp (less expensive ^ ) Grumman's really suitable for frequent
>8000+' DA takeoffs ?


Any non-turbocharged aircraft will have issues with 8000' + DAs. The
bigger the engine the heavier the bird. You will need to manage the
load and watch your conditions no matter what you choose to purchase.

z

[Dave Stadt]

"Robert M. Gary" > wrote in message
om...
> (JimT96309) wrote in message
>...
> > I am currently interested in an older C-172 (Cont. 0-300 engine) that
has an
> > STC for auto gas. My questions are:
> >
> > 1. Can I continue to use AVgas instead of auto fuel?
> >
> > 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've
been able
> > to get out lightly loaded (me and one in the right seat) at a density
altitude
> > of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp.
What
> > difference would I see with the 15 fewer horses up front?
>
> I'm not 100% sure about the Big Bear area, but in most parts of
> California the FAA prohibits the use of autogas. Autogas in Ca usually
> (depending on the county) contains MTBE which is prohibited by the FAA
> because it eats fuel lines.
>
> -Robert

The FAA does not prohibit using auto fuel. They prohibit using fuel with
alcohol. Airports can purchase autogas without the alcohol. MTBE is not a
problem. The problem is natural rubber parts which are damaged by alcohol,
not fuel lines. Might be time to review your STC.

[Newps]

"zatatime" > wrote in message
...
>
>
> Any non-turbocharged aircraft will have issues with 8000' + DAs. The
> bigger the engine the heavier the bird. You will need to manage the
> load and watch your conditions no matter what you choose to purchase.

While that's true you couldn't make a much worse choice than a Grumman.

[zatatime]

On Wed, 2 Jun 2004 17:48:58 -0600, "Newps" >
wrote:

>
>"zatatime" > wrote in message
...
>>
>>
>> Any non-turbocharged aircraft will have issues with 8000' + DAs. The
>> bigger the engine the heavier the bird. You will need to manage the
>> load and watch your conditions no matter what you choose to purchase.
>
>While that's true you couldn't make a much worse choice than a Grumman.
>


My point was to open the poster up to the idea that a different
airplane may better suit his needs. While I'm not a big fan of most
Grummans I know people who love them so I offered it as one of two
alternatives. Maybe I should have said something like...Insert
alternative manufacturer here...instead of being specific.

z

[Newps]

"zatatime" > wrote in message
...
> >While that's true you couldn't make a much worse choice than a Grumman.
> >
>
>
> My point was to open the poster up to the idea that a different
> airplane may better suit his needs. While I'm not a big fan of most
> Grummans I know people who love them so I offered it as one of two
> alternatives. Maybe I should have said something like...Insert
> alternative manufacturer here...instead of being specific.

A Grumman has its place. But it ain't trying to get off the ground at an
8000' DA.

[Orval Fairbairn]

In article >,
(Robert M. Gary) wrote:

> (JimT96309) wrote in message
> >...
> > I am currently interested in an older C-172 (Cont. 0-300 engine) that has
> > an
> > STC for auto gas. My questions are:
> >
> > 1. Can I continue to use AVgas instead of auto fuel?
> >
> > 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been
> > able
> > to get out lightly loaded (me and one in the right seat) at a density
> > altitude
> > of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp.
> > What
> > difference would I see with the 15 fewer horses up front?
>
> I'm not 100% sure about the Big Bear area, but in most parts of
> California the FAA prohibits the use of autogas. Autogas in Ca usually
> (depending on the county) contains MTBE which is prohibited by the FAA
> because it eats fuel lines.
>
> -Robert

WRONG! MTBE is an approved additive, while alcohol is NOT.

[G.R. Patterson III]

"Robert M. Gary" wrote:
>
> I'm not 100% sure about the Big Bear area, but in most parts of
> California the FAA prohibits the use of autogas. Autogas in Ca usually
> (depending on the county) contains MTBE which is prohibited by the FAA
> because it eats fuel lines.

--------------- begin quote -------------------

On December 14, 1992, EAA received clarification from the FAA that: "Automobile
gasoline blended with MTBE is approved for use in aircraft that are approved for use
of automobile gasoline STC's." EAA, Petersen Aviation and others have worked with the
FAA to have MTBE "approved" based on the common industry knowledge that it has been
in automobile gasoline for years. The FAA's determination that gasoline blended with
MTBE can be used safely in aircraft (that are STC approved) was based, in part, on
FAA tests, research and review of service difficulty reports. No material
compatibility or performance problems were found. The FAA also approved the use of
automobile gasoline that contains ETBE on December 1, 1995. This approval was based
on flight test, ground tests and material compatibility test performed by EAA, FAA
and Petersen Aviation.

George Patterson
None of us is as dumb as all of us.

[Jay Honeck]

> 1. Can I continue to use AVgas instead of auto fuel?

Yes, but:

a) Your engine will run cleaner, better and longer on unleaded car gas

and

b) By burning auto fuel you will save enough over the life of the engine to
buy another new engine.

The Mogas STC is the best value in flying. You'd be crazy not to use it if
you've got it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[[email protected]]

Jay Honeck > wrote:
:> 1. Can I continue to use AVgas instead of auto fuel?

: Yes, but:

: a) Your engine will run cleaner, better and longer on unleaded car gas

: and

: b) By burning auto fuel you will save enough over the life of the engine to
: buy another new engine.

: The Mogas STC is the best value in flying. You'd be crazy not to use it if
: you've got it.

*Particularly* on a low-compression engine. The Cont O-200/O-300's in the
older Cessnas are much happier on cargas. Same thing for the low-compression Lyc.
O-320's and O-540s. The high-compression engines (like my 180 hp O-360) are a little
bit more marginal... not from an engine life, but from a detonation margin. The
Peterson STC specifies 91 AKI (R+M/2), but the aviation lean rating (91 of the 91/96
of this engine's type certificated fuel) is closer to the Motor octane rating of the
AKI. Since 91 AKI cargas might have a Motor rating of 86 or so, it's a bit marginal.
I run 93 AKI and keep at least 15% 100LL in the takeoff tank for the octane boost of
the TEL. The effects of TEL are quite nonlinear (i.e. a little gives you a lot, but a
lot doesn't give much more). That said, I've got about 200 hours of cargas on my
plane and it's so far happier (as am I having saved over $1500 so far).

-Cory



--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[Robert M. Gary]

"G.R. Patterson III" > wrote in message >...
> "Robert M. Gary" wrote:
> >
> > I'm not 100% sure about the Big Bear area, but in most parts of
> > California the FAA prohibits the use of autogas. Autogas in Ca usually
> > (depending on the county) contains MTBE which is prohibited by the FAA
> > because it eats fuel lines.
>
> --------------- begin quote -------------------
>
> On December 14, 1992, EAA received clarification from the FAA that: "Automobile
> gasoline blended with MTBE is approved for use in aircraft that are approved for use
> of automobile gasoline STC's." EAA, Petersen Aviation and others have worked with the
> FAA to have MTBE "approved" based on the common industry knowledge that it has been
> in automobile gasoline for years. The FAA's determination that gasoline blended with
> MTBE can be used safely in aircraft (that are STC approved) was based, in part, on
> FAA tests, research and review of service difficulty reports. No material
> compatibility or performance problems were found. The FAA also approved the use of
> automobile gasoline that contains ETBE on December 1, 1995. This approval was based
> on flight test, ground tests and material compatibility test performed by EAA, FAA
> and Petersen Aviation.

That's interesting. I called the EAA a year ago when I was looking at
buying another Aeronca and was told otherwise. I guess you can't
necessarily trust the guy on the phone.

[Robert M. Gary]

"Jay Honeck" > wrote in message news:<ivFvc.36969$3x.36311@attbi_s54>...
> > 1. Can I continue to use AVgas instead of auto fuel?
>
> Yes, but:
>
> a) Your engine will run cleaner, better and longer on unleaded car gas
>
> and
>
> b) By burning auto fuel you will save enough over the life of the engine to
> buy another new engine.
>
> The Mogas STC is the best value in flying. You'd be crazy not to use it if
> you've got it.

We had create luck with autogas in the Chief. Kept the engine clean.
The lower octane really makes things run nicer too. 100LL would crud
up the works pretty fast. This is especially bad for those planes that
don't have a mixture control.

[Jay Honeck]

> We had create luck with autogas in the Chief. Kept the engine clean.
> The lower octane really makes things run nicer too. 100LL would crud
> up the works pretty fast. This is especially bad for those planes that
> don't have a mixture control.

I paid $3.30 a gallon for Avgas in Ankeny today!

I paid $1.92 for mogas in Iowa City yesterday.

The math is self-evident -- mogas is the way to go!

BTW: What planes don't have mixture controls? (Beside turbines and jets?)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Aaron Coolidge]

Jay Honeck > wrote:
: I paid $3.30 a gallon for Avgas in Ankeny today!

: I paid $1.92 for mogas in Iowa City yesterday.

: The math is self-evident -- mogas is the way to go!

I paid $2.29 for 93 octane premium unleaded in Mansfield the other day.
I paid $2.60 for 100LL in Columbia County, NY (1B1) the other day.
For me, the math is self evident, but the other way! (Break even with STC
costs @ 10000 gallons or 1000 hours!)

: BTW: What planes don't have mixture controls? (Beside turbines and jets?)
A lot of older, pre WW2 airplanes with small engines, less than 85 HP.
--
Aaron Coolidge (N9376J)

[MikeM]

Aaron Coolidge wrote:

> I paid $2.29 for 93 octane premium unleaded in Mansfield the other day.
> I paid $2.60 for 100LL in Columbia County, NY (1B1) the other day.
> For me, the math is self evident, but the other way! (Break even with STC
> costs @ 10000 gallons or 1000 hours!)

Something is wrong with your math.

@ $0.31 price difference per gallon, it would only take 741 gallons to
pay for the $230 STC (O470, 230HP, $1 per HP).

My price difference between 100LL and 86 Octane autogas has typically been
$0.75 to $1 per gallon. I figure that between overhauls of my engine (~2000
hours, buring 12 gph), I saved a minimum of 12 * 2000 * 0.75 = $18,000,
which is what the last overhaul cost...

MikeM

[jls]

"Jay Honeck" > wrote in message
news:1cMvc.36339$pt3.35172@attbi_s03...
> > We had create luck with autogas in the Chief. Kept the engine clean.
> > The lower octane really makes things run nicer too. 100LL would crud
> > up the works pretty fast. This is especially bad for those planes that
> > don't have a mixture control.
>
> I paid $3.30 a gallon for Avgas in Ankeny today!
>
> I paid $1.92 for mogas in Iowa City yesterday.
>
> The math is self-evident -- mogas is the way to go!
>
> BTW: What planes don't have mixture controls? (Beside turbines and
jets?)

Most of the Bendix/Stromberg carburetors have the mix controls wired full
rich. These carbs are found on C-85's and A-65's which power the small
aircraft like Cubs, Luscombes, Taylorcraft, Aeroncas, etc.

Even if the mixture control on a Stromberg is operative, it's ordinarily
impossible to starve the mixture. The leaning process does not occur until
the engine is turning at 1500 rpm or above.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>

[Aaron Coolidge]

MikeM > wrote:
: Aaron Coolidge wrote:
:> I paid $2.29 for 93 octane premium unleaded in Mansfield the other day.
:> I paid $2.60 for 100LL in Columbia County, NY (1B1) the other day.
:> For me, the math is self evident, but the other way! (Break even with STC
:> costs @ 10000 gallons or 1000 hours!)

: Something is wrong with your math.

: @ $0.31 price difference per gallon, it would only take 741 gallons to
: pay for the $230 STC (O470, 230HP, $1 per HP).

: My price difference between 100LL and 86 Octane autogas has typically been
: $0.75 to $1 per gallon. I figure that between overhauls of my engine (~2000
: hours, buring 12 gph), I saved a minimum of 12 * 2000 * 0.75 = $18,000,
: which is what the last overhaul cost...

: MikeM

Ah, to have a low compression engine. My plane is a Cherokee 180, with a
"high compression" O-360. The autofuel STC is very involved. You need to
replace the electric fuel pump with 2 different electric fuel pumps. You need
to re-plumb the left (or was it right) fuel tank with larger pipes. You
replumb the fuel selector to engine with larger pipes. You replumb the flex
hoses with larger flex hoses. You then can burn *91* Octane car fuel.
As Cory P. pointed out, the detonation margins on 91 octane are small. So,
you'd probably end up using 93 octane. The fuel tanks are placarded for
"91/96 Octane Minimum".

By the way, the STC is > $2000 for this plane, with 40 hours of install time.
Saving $0.30/gal takes a lot of gallons to even pay for the STC.

I also live in an area where carrying fuel in containers is legally
challenging. You're allowed a max of 2, 5 gallon containers without hazmat
placards, etc. Besides, the oil companies seem to have choses this area
to test their "Los Angeles" style pricing!
--
Aaron Coolidge

[G.R. Patterson III]

MikeM wrote:
>
> Something is wrong with your math.
>
> @ $0.31 price difference per gallon, it would only take 741 gallons to
> pay for the $230 STC (O470, 230HP, $1 per HP).

Perhaps he's also including the cost of the rig Jay bought and built to haul
gasoline.

George Patterson
None of us is as dumb as all of us.

[Dave Stadt]

" jls" > wrote in message
...
>
> "Jay Honeck" > wrote in message
> news:1cMvc.36339$pt3.35172@attbi_s03...
> > > We had create luck with autogas in the Chief. Kept the engine clean.
> > > The lower octane really makes things run nicer too. 100LL would crud
> > > up the works pretty fast. This is especially bad for those planes that
> > > don't have a mixture control.
> >
> > I paid $3.30 a gallon for Avgas in Ankeny today!
> >
> > I paid $1.92 for mogas in Iowa City yesterday.
> >
> > The math is self-evident -- mogas is the way to go!
> >
> > BTW: What planes don't have mixture controls? (Beside turbines and
> jets?)
>
> Most of the Bendix/Stromberg carburetors have the mix controls wired full
> rich. These carbs are found on C-85's and A-65's which power the small
> aircraft like Cubs, Luscombes, Taylorcraft, Aeroncas, etc.
>
> Even if the mixture control on a Stromberg is operative, it's ordinarily
> impossible to starve the mixture. The leaning process does not occur
until
> the engine is turning at 1500 rpm or above.

Never the less it is an effectivfe mixture control despite what many people
think. Idle cutoff has nothing to do with effective mixture control.

[Jay Masino]

Aaron Coolidge > wrote:
> By the way, the STC is > $2000 for this plane, with 40 hours of install time.
> Saving $0.30/gal takes a lot of gallons to even pay for the STC.
> I also live in an area where carrying fuel in containers is legally
> challenging. You're allowed a max of 2, 5 gallon containers without hazmat
> placards, etc. Besides, the oil companies seem to have choses this area
> to test their "Los Angeles" style pricing!

Exactly. In addition to 180s, 160hp O-320s are also included (like
Warrior 161s or Cherokee 140s modified to 160hp).

--- Jay


--
__!__
Jay and Teresa Masino ___(_)___
http://www2.ari.net/jmasino ! ! !
http://www.oceancityairport.com
http://www.oc-adolfos.com

[jls]

"Dave Stadt" > wrote in message
y.com...
>
[...]
> > Most of the Bendix/Stromberg carburetors have the mix controls wired
full
> > rich. These carbs are found on C-85's and A-65's which power the small
> > aircraft like Cubs, Luscombes, Taylorcraft, Aeroncas, etc.
> >
> > Even if the mixture control on a Stromberg is operative, it's ordinarily
> > impossible to starve the mixture. The leaning process does not occur
> until
> > the engine is turning at 1500 rpm or above.
>
> Never the less it is an effectivfe mixture control despite what many
people
> think. Idle cutoff has nothing to do with effective mixture control.

You are correct. I use my mixture control on my Stromberg every time I
fly. A Stromberg aficionado in the 120/140 group has published all kinds of
helpful material on the Stromberg, including how to set up a longer mixture
lever for better, more accurate control.

[[email protected]]

Amen to that... I waffled for awhile, but ended up buying the STC for ours.
I've got an A&P/IA that worked with me, so I did most of the install. It was $1500
when we did it a year ago (it had gone up from $1100 the preceeding year... DOH!).
Since I did the labor, that's about all it cost. Around here (SW-VA), "premium" is 93,
and "mid-grade" is 89... so there's only one choice. Also, 93 is $1.99 right now
(less $0.125 road-tax rebate), and base-rate 100LL is $2.50. It still makes sense.
Last year I flew 150 hours, and the fuel price difference was even more so and I've
already paid for the STC.

I've pretty much convinced myself that it's fine on the engine. In cruise,
there's absolutely no question that it's fine. If I'm flying locally, I can fly 2
hours on a single tank without making a wing too heavy. Then I don't even use any
100LL except for takeoff. It was perfect for instrument training.

Another noteworthy point is that field elevation here is 2100'. The DA is
typically 3500-4000' in the summer, when detonation potential is highest. Going
'full-rich' is *WAY* richer than necessary under those conditions and gives a bit more
margin. It's a noticable decrease in power full-rich, though.

YMMV
-Cory

Aaron Coolidge > wrote:
: Ah, to have a low compression engine. My plane is a Cherokee 180, with a
: "high compression" O-360. The autofuel STC is very involved. You need to
: replace the electric fuel pump with 2 different electric fuel pumps. You need
: to re-plumb the left (or was it right) fuel tank with larger pipes. You
: replumb the fuel selector to engine with larger pipes. You replumb the flex
: hoses with larger flex hoses. You then can burn *91* Octane car fuel.
: As Cory P. pointed out, the detonation margins on 91 octane are small. So,
: you'd probably end up using 93 octane. The fuel tanks are placarded for
: "91/96 Octane Minimum".

: By the way, the STC is > $2000 for this plane, with 40 hours of install time.
: Saving $0.30/gal takes a lot of gallons to even pay for the STC.

: I also live in an area where carrying fuel in containers is legally
: challenging. You're allowed a max of 2, 5 gallon containers without hazmat
: placards, etc. Besides, the oil companies seem to have choses this area
: to test their "Los Angeles" style pricing!
: --
: Aaron Coolidge


--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[[email protected]]

Jay Masino > wrote:
: Exactly. In addition to 180s, 160hp O-320s are also included (like
: Warrior 161s or Cherokee 140s modified to 160hp).

Actually, the 140's modified to 160 rarely quality. The cowling style must be
the later clamshell fiberglass version with the dual exhaust. If it's just a 140/160
with the flip-up style aluminum cowling, it doesn't qualify for the STC. Too hot back
by the muffler on the firewall.

The part that really irks me is the reason for the dual fuel pumps is
inadequate fuel flow. The logical problem is that raising the compression ratio of an
engine DOESN'T CHANGE THE FUEL FLOW! It's an O-360... it suck/squeeze/bang/blow's 360
CI of mixture every cycle... it's just that a higher CR gets a bit more bang out the
bang part. I could see the muffler issue (hotter EGT with higher CR). If a Cherokee
150's (lower compression 160 with clamshell cowling) fuel pump is adequate for the
low-compression STC at $1/hp, putting higher compression pistons doesn't change that
in the slightest.

Yet another way the FAA is keeping you safe by being inconsistent with
physics, but consistently performing CYA.

-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[Jay Masino]

wrote:
> Jay Masino > wrote:
> : Exactly. In addition to 180s, 160hp O-320s are also included (like
> : Warrior 161s or Cherokee 140s modified to 160hp).

> Actually, the 140's modified to 160 rarely quality. The cowling style must be
> the later clamshell fiberglass version with the dual exhaust. If it's just a 140/160
> with the flip-up style aluminum cowling, it doesn't qualify for the STC. Too hot back
> by the muffler on the firewall.

Wow. That's interesting to know. I wonder if a modified/160hp 140, with
the Powerflow exhaust would qualify. The muffler is outside the cowling,
and the collector assembly is in the front, underneath the engine.

--- Jay



--
__!__
Jay and Teresa Masino ___(_)___
http://www2.ari.net/jmasino ! ! !
http://www.oceancityairport.com
http://www.oc-adolfos.com

[G.R. Patterson III]

wrote:
>
> Yet another way the FAA is keeping you safe by being inconsistent with
> physics, but consistently performing CYA.

The FAA has nothing to do with it except as the issuer of the certificate. People
like EAA and Petersen work with one of the plane/engine combos until they get it to
run reliably on car gas. These people have determined by empirical experiment that
these modifications are necessary.

George Patterson
None of us is as dumb as all of us.

[xyzzy]

Aaron Coolidge wrote:

> Jay Honeck > wrote:
>
> : BTW: What planes don't have mixture controls? (Beside turbines and jets?)
> A lot of older, pre WW2 airplanes with small engines, less than 85 HP.

And the newly certified Liberty XL2 (prolly will be the case with all
FADEC engines). I wonder if it will be possible to get an autogas STC
for a FADEC engine like that.

[[email protected]]

G.R. Patterson III > wrote:
: The FAA has nothing to do with it except as the issuer of the certificate. People
: like EAA and Petersen work with one of the plane/engine combos until they get it to
: run reliably on car gas. These people have determined by empirical experiment that
: these modifications are necessary.

True, but my point is that the empirical experiments were done twice with
effectively identical setups. At the time the low-compression tests were done, the
fuel flow was deemed acceptable. At the time the high-compression tests were done,
the same fuel flow was unacceptable. I think either the test "sample" (i.e. airplane)
was substantially different (worn or extra-good pump in one), or they changed the
requirements between the two tests.

Another more subtle change for the Cherokee setup was a change from electric
boost pump being in parallel with the engine pump. Now the two electric pumps are in
parallel, but in series before the engine pump. Not the engine pump diaphram is a
single-point of failure. Also, the gascolator and cabin primer is not on the
*pressure* side of the electric pumps.... subtle changes that have significant safety
ramifications IMO.

FWIW, I talked with Petersen at length about the detonation testing they did
before we shelled out the cash. He said they did quick turn-around flights in a 100
degree day, with 2 mile low-speed taxis in between takeoffs. No vapor lock, and
could't get the engine to detonate... even with 89 AKI cargas. He said he tried to
get the FAA to agree to 89 on the STC, but they wanted 91 for more margin.

-Cory
--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[[email protected]]

Jay Masino > wrote:
: Wow. That's interesting to know. I wonder if a modified/160hp 140, with
: the Powerflow exhaust would qualify. The muffler is outside the cowling,
: and the collector assembly is in the front, underneath the engine.

Unless they specifically tested that combination, I'm sure the answer is no.
You could ask him, or petition the FSDO (HA HA HA!!!). Since the Powerflow alegedly
scavenges more gasses during the combustion event, the fuel flow could increase a bit
more. Also, the oil cooler isn't in the same place. Most likely it would require
flight testing akin to the original STC certification (read: PITA and expensive).

-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[Ray Andraka]

That's the old pump setup for the O-540 for early Sixes. I'll bet the test aircraft was
an older model with the twin electric fuel pumps in series with the mechanical pump, and
since that was what it was tested with, that is what all planes aspiring to the STC have
to be 'upgraded' to.

wrote:

> Another more subtle change for the Cherokee setup was a change from electric
> boost pump being in parallel with the engine pump. Now the two electric pumps are in
> parallel, but in series before the engine pump. Not the engine pump diaphram is a
> single-point of failure. Also, the gascolator and cabin primer is not on the
> *pressure* side of the electric pumps.... subtle changes that have significant safety
> ramifications IMO.
>
>
> -Cory
> --
> ************************************************** ***********************
> * The prime directive of Linux: *
> * - learn what you don't know, *
> * - teach what you do. *
> * (Just my 20 USm$) *
> ************************************************** ***********************

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

[Robert M. Gary]

"Jay Honeck" > wrote in message news:<1cMvc.36339$pt3.35172@attbi_s03>...
> > We had create luck with autogas in the Chief. Kept the engine clean.
> > The lower octane really makes things run nicer too. 100LL would crud
> > up the works pretty fast. This is especially bad for those planes that
> > don't have a mixture control.
>
> I paid $3.30 a gallon for Avgas in Ankeny today!
>
> I paid $1.92 for mogas in Iowa City yesterday.
>
> The math is self-evident -- mogas is the way to go!
>
> BTW: What planes don't have mixture controls? (Beside turbines and jets?)

The J-3 didn't. I believe one of the Chief's didn't. I think mixture
was an optional item on all the 40's 65hp planes. Even when you had
mixture, it didn't do anything on the ground. It only effected you at
cruise power.

[Jay Honeck]

> The J-3 didn't. I believe one of the Chief's didn't. I think mixture
> was an optional item on all the 40's 65hp planes. Even when you had
> mixture, it didn't do anything on the ground. It only effected you at
> cruise power.

Thanks, all, for the info about mixture-less aircraft. I've only flown a
Cub once, and (apparently) never noticed the lack of a mixture control. (I
don't think I ever touched the throttle -- the guy in back was working the
power...) And I sure had no idea that this feature (or lack thereof) was
universal to so many small-engined, older airplanes.

Another learning experience to chalk up to this newsgroup....

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Carl Orton]

As long as we're on the subject of mogas STCs...

My still new-to-me '67 172H already had the Petersen STC installed.

But I've been chicken to try it! Guess I'm concerned that vapor lock or
lower quality or whatever other old wives tales will strike me dead.

Is there *anything* I should watch for if I just suddenly decide to fill 'er
up with mogas some day? Like different start procedure, or longer takeoff
run, or ??? Or, is mogas the EXACT same in every other way (yeah, I know you
guys are gonna chime in with "less bucks, burns cleaner, engine happier,
etc.")

Thanks;
Carl


"JimT96309" > wrote in message
...
> I am currently interested in an older C-172 (Cont. 0-300 engine) that has
an
> STC for auto gas. My questions are:
>
> 1. Can I continue to use AVgas instead of auto fuel?
>
> 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've been
able
> to get out lightly loaded (me and one in the right seat) at a density
altitude
> of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp.
What
> difference would I see with the 15 fewer horses up front?
>
> 3. Can you give me a rough idea of cost to add a 2nd Nav-comm with
Glideslope
> and then have the whole thing certified for IFR? I would probably try to
find a
> good quality used one from one of the local shops.
>
> Thanks for any help you can give to a rookie getting ready to make a first
> purchase.
>
> Jim
>
>

[G. Burkhart]

"Jay Honeck" > wrote in message
news:ZFtwc.45447$pt3.6238@attbi_s03...
> > The J-3 didn't. I believe one of the Chief's didn't. I think mixture
> > was an optional item on all the 40's 65hp planes. Even when you had
> > mixture, it didn't do anything on the ground. It only effected you at
> > cruise power.
>
> Thanks, all, for the info about mixture-less aircraft. I've only flown a
> Cub once, and (apparently) never noticed the lack of a mixture control.
(I
> don't think I ever touched the throttle -- the guy in back was working the
> power...) And I sure had no idea that this feature (or lack thereof) was
> universal to so many small-engined, older airplanes.

There's a few features that older aircraft don't have. Some with the
Stromberg (?) carbs have them safety wired fully rich and use the mag switch
to shut down. It's kind of like shutting off a computer by just pulling the
power cord out of the wall. My mixture control is functional, above 1500 rpm
or so, so in order to shut down from idle, I pull the mixture then firewall
the throttle and it will kill the engine. Other features I don't have on my
plane are rudder pedals (Ercoupe), flaps or a trim tab. It's what makes
these older aircraft 'unique'.

I did my training in a C150 and when I bought my Ercoupe, I had to learn how
to fly without the use of flaps, rudder pedals or a trim tab. There is an
option to add a trim tab for about $600 and rudder pedals can be added but
I'm not interested in those options.

[[email protected]]

Carl Orton > wrote:
: But I've been chicken to try it! Guess I'm concerned that vapor lock or
: lower quality or whatever other old wives tales will strike me dead.

Put it in one tank first. Takeoff on 100LL, cruise on mogas. If you fly less
than 2 hours, you can pretty much burn all mogas that way.

: Is there *anything* I should watch for if I just suddenly decide to fill 'er
: up with mogas some day? Like different start procedure, or longer takeoff
: run, or ??? Or, is mogas the EXACT same in every other way (yeah, I know you
: guys are gonna chime in with "less bucks, burns cleaner, engine happier,
: etc.")

It alegedly will start better... especially when cold because the vapor
pressure is a higher. I've never noticed a difference. I've got the Peterson RVP
gauge and the 100LL tends to have about 1 psi (or inHg... don't remember) lower...
very slight difference, really. The one important thing to do if you put mogas in
your plane is to test it for alcohol. You can google up on the exact procedure, but
it's not hard. Get a clear container, preferrably tall and thin. Put in about 10%
water and mark the level on the side of the container. Add the other 90% fuel.
Shake and then let settle. If the "water" level went up, there's alcohol in it and
you can't use it.

For a low-compression engine, 87 AKI is fine... don't need the high-test. If
you end up running it, I'd highly recommend a fuel filter. I rigged a (very
goofy-looking) pour spout on my 6-gallon cans that has a spin-on water-absorbing fuel
filter (looks like an oil filter) inline. Since I did that, I get absolutely clean
fuel, free of water, and good peace of mind.

Mogas is different operationally in one very important aspect... it *STINKS!*.
100LL is pretty sweet-smelling stuff by comparison.

-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[Dave Stadt]

"G. Burkhart" > wrote in message
news:opwwc.8392$HG.7233@attbi_s53...
> "Jay Honeck" > wrote in message
> news:ZFtwc.45447$pt3.6238@attbi_s03...
> > > The J-3 didn't. I believe one of the Chief's didn't. I think mixture
> > > was an optional item on all the 40's 65hp planes. Even when you had
> > > mixture, it didn't do anything on the ground. It only effected you at
> > > cruise power.
> >
> > Thanks, all, for the info about mixture-less aircraft. I've only flown
a
> > Cub once, and (apparently) never noticed the lack of a mixture control.
> (I
> > don't think I ever touched the throttle -- the guy in back was working
the
> > power...) And I sure had no idea that this feature (or lack thereof)
was
> > universal to so many small-engined, older airplanes.
>
> There's a few features that older aircraft don't have. Some with the
> Stromberg (?) carbs have them safety wired fully rich and use the mag
switch
> to shut down. It's kind of like shutting off a computer by just pulling
the
> power cord out of the wall.

Actually it is like shutting off your car. Not a big deal by any means.

[[email protected]]

Dave Stadt > wrote:
: Actually it is like shutting off your car. Not a big deal by any means.

Actually, it's not *quite* like that. A car engine:
- Isn't timed to run at "really" low speeds.
- Doesn't have as much inertia as the propeller.
- Doesn't have as much idle load as a propeller at 500 rpm.
- Isn't air-cooled.

I have observed extremely low-speed dieseling on both high-compression and
low-compression aircraft engines when shut down with the mags after flight on cargas.
It initially worried me, but when I thought about it more, the following two things
were important:

- VERY low speeds (50-100 rpm), so 25x more time for the fuel to preignite than at
takeoff conditions (2500 rpm).
- VERY high manifold pressure due to idle throttle at very low RPM... almost full MP.

Both of those equate to serious "lugging" conditions on a hot cylinder head.

YMMV
-Cory



--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[Newps]

If your worried about it, which there is no reason for, then just mix it
with the 100LL. Operate the plane the same way no matter what kind of gas
you have.



"Carl Orton" > wrote in message
...
> As long as we're on the subject of mogas STCs...
>
> My still new-to-me '67 172H already had the Petersen STC installed.
>
> But I've been chicken to try it! Guess I'm concerned that vapor lock or
> lower quality or whatever other old wives tales will strike me dead.
>
> Is there *anything* I should watch for if I just suddenly decide to fill
'er
> up with mogas some day? Like different start procedure, or longer takeoff
> run, or ??? Or, is mogas the EXACT same in every other way (yeah, I know
you
> guys are gonna chime in with "less bucks, burns cleaner, engine happier,
> etc.")
>
> Thanks;
> Carl
>
>
> "JimT96309" > wrote in message
> ...
> > I am currently interested in an older C-172 (Cont. 0-300 engine) that
has
> an
> > STC for auto gas. My questions are:
> >
> > 1. Can I continue to use AVgas instead of auto fuel?
> >
> > 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've
been
> able
> > to get out lightly loaded (me and one in the right seat) at a density
> altitude
> > of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp.
> What
> > difference would I see with the 15 fewer horses up front?
> >
> > 3. Can you give me a rough idea of cost to add a 2nd Nav-comm with
> Glideslope
> > and then have the whole thing certified for IFR? I would probably try to
> find a
> > good quality used one from one of the local shops.
> >
> > Thanks for any help you can give to a rookie getting ready to make a
first
> > purchase.
> >
> > Jim
> >
> >
>
>

[Jay Honeck]

> Is there *anything* I should watch for if I just suddenly decide to fill
'er
> up with mogas some day? Like different start procedure, or longer takeoff
> run, or ??? Or, is mogas the EXACT same in every other way (yeah, I know
you
> guys are gonna chime in with "less bucks, burns cleaner, engine happier,
> etc.")

We use 87 octane unleaded mogas and 100 octane avgas absolutely
interchangeably in our two-year old Lycoming O-540.

No difference has been noted in engine operation, nor is there any
difference in cylinder or exhaust gas temps as noted on our JPI EDM-700
engine analyzer. There is also no difference in fuel flow (as measured with
our JPI FS-450 fuel totalizer), nor is there any difference in engine
leaning at altitude.

In fact, there is precisely no difference in performance at all.

There are really only two differences:

1. Mogas is about a buck a gallon less.
2. We don't fail mag checks (due to lead-fouled plugs) on mogas.

It's the best deal in aviation. If you've got the STC, and are not using
it, you are quite literally burning a 50 dollar bill every time you gas up.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Carl Orton]

Well, thanks for the assurances, folks. Guess I'll have to give it a try
one of these days. (now to search the archives for Jay's Mighty Grape
contraption!!!).


"Carl Orton" > wrote in message
...
> As long as we're on the subject of mogas STCs...
>
> My still new-to-me '67 172H already had the Petersen STC installed.
>
> But I've been chicken to try it! Guess I'm concerned that vapor lock or
> lower quality or whatever other old wives tales will strike me dead.
>
> Is there *anything* I should watch for if I just suddenly decide to fill
'er
> up with mogas some day? Like different start procedure, or longer takeoff
> run, or ??? Or, is mogas the EXACT same in every other way (yeah, I know
you
> guys are gonna chime in with "less bucks, burns cleaner, engine happier,
> etc.")
>
> Thanks;
> Carl
>
>
> "JimT96309" > wrote in message
> ...
> > I am currently interested in an older C-172 (Cont. 0-300 engine) that
has
> an
> > STC for auto gas. My questions are:
> >
> > 1. Can I continue to use AVgas instead of auto fuel?
> >
> > 2. I often fly into/out of Big Bear City, Ca. (elev. 6500ft.) I've
been
> able
> > to get out lightly loaded (me and one in the right seat) at a density
> altitude
> > of 8,100 with one of our clubs 172s with the 320H2AD engines at 160 hp.
> What
> > difference would I see with the 15 fewer horses up front?
> >
> > 3. Can you give me a rough idea of cost to add a 2nd Nav-comm with
> Glideslope
> > and then have the whole thing certified for IFR? I would probably try to
> find a
> > good quality used one from one of the local shops.
> >
> > Thanks for any help you can give to a rookie getting ready to make a
first
> > purchase.
> >
> > Jim
> >
> >
>
>

[G.R. Patterson III]

Carl Orton wrote:
>
> Is there *anything* I should watch for if I just suddenly decide to fill 'er
> up with mogas some day?

You probably will notice that it starts more easily. That's all I can think of. If
there were things to "look out for", there wouldn't be an STC.

George Patterson
None of us is as dumb as all of us.

[Jay Honeck]

> Well, thanks for the assurances, folks. Guess I'll have to give it a try
> one of these days. (now to search the archives for Jay's Mighty Grape
> contraption!!!).

http://alexisparkinn.com/fuel_truck.htm

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Carl Orton]

Thanks, Jay!

"Jay Honeck" > wrote in message
news:oJRwc.53433$3x.13569@attbi_s54...
> > Well, thanks for the assurances, folks. Guess I'll have to give it a
try
> > one of these days. (now to search the archives for Jay's Mighty Grape
> > contraption!!!).
>
> http://alexisparkinn.com/fuel_truck.htm
>
> :-)
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>

[Robert M. Gary]

"Dave Stadt" > wrote in message >...
> "G. Burkhart" > wrote in message
> news:opwwc.8392$HG.7233@attbi_s53...
> > "Jay Honeck" > wrote in message
> > news:ZFtwc.45447$pt3.6238@attbi_s03...
> > > > The J-3 didn't. I believe one of the Chief's didn't. I think mixture
> > > > was an optional item on all the 40's 65hp planes. Even when you had
> > > > mixture, it didn't do anything on the ground. It only effected you at
> > > > cruise power.
> > >
> > > Thanks, all, for the info about mixture-less aircraft. I've only flown
> a
> > > Cub once, and (apparently) never noticed the lack of a mixture control.
> (I
> > > don't think I ever touched the throttle -- the guy in back was working
> the
> > > power...) And I sure had no idea that this feature (or lack thereof)
> was
> > > universal to so many small-engined, older airplanes.
> >
> > There's a few features that older aircraft don't have. Some with the
> > Stromberg (?) carbs have them safety wired fully rich and use the mag
> switch
> > to shut down. It's kind of like shutting off a computer by just pulling
> the
> > power cord out of the wall.
>
> Actually it is like shutting off your car. Not a big deal by any means.

Just don't touch the prop aftewards (unless you want it to start).
When I had the Chief we had to shut it down with the mags. Usually a
20 degree turn on the prop was all we needed to hand start it. Now, if
some line guy were to "move" the prop, he'd have a hand full of his
hands (if the mags didn't ground). At least with a mixture airplane
you shouldn't have as much fireable fuel in the cylinders.

-Robert

[Dave Stadt]

"Robert M. Gary" > wrote in message
om...
> "Dave Stadt" > wrote in message
>...
> > "G. Burkhart" > wrote in message
> > news:opwwc.8392$HG.7233@attbi_s53...
> > > "Jay Honeck" > wrote in message
> > > news:ZFtwc.45447$pt3.6238@attbi_s03...
> > > > > The J-3 didn't. I believe one of the Chief's didn't. I think
mixture
> > > > > was an optional item on all the 40's 65hp planes. Even when you
had
> > > > > mixture, it didn't do anything on the ground. It only effected you
at
> > > > > cruise power.
> > > >
> > > > Thanks, all, for the info about mixture-less aircraft. I've only
flown
> > a
> > > > Cub once, and (apparently) never noticed the lack of a mixture
control.
> > (I
> > > > don't think I ever touched the throttle -- the guy in back was
working
> > the
> > > > power...) And I sure had no idea that this feature (or lack
thereof)
> > was
> > > > universal to so many small-engined, older airplanes.
> > >
> > > There's a few features that older aircraft don't have. Some with the
> > > Stromberg (?) carbs have them safety wired fully rich and use the mag
> > switch
> > > to shut down. It's kind of like shutting off a computer by just
pulling
> > the
> > > power cord out of the wall.
> >
> > Actually it is like shutting off your car. Not a big deal by any means.
>
> Just don't touch the prop aftewards (unless you want it to start).
> When I had the Chief we had to shut it down with the mags. Usually a
> 20 degree turn on the prop was all we needed to hand start it. Now, if
> some line guy were to "move" the prop, he'd have a hand full of his
> hands (if the mags didn't ground). At least with a mixture airplane
> you shouldn't have as much fireable fuel in the cylinders.
>
> -Robert

I wouldn't bet a plug nickel on your last statement.

[Robert M. Gary]

"Dave Stadt" > wrote in message >...
> "Robert M. Gary" > wrote in message
> om...
> > "Dave Stadt" > wrote in message
> >...
> > > "G. Burkhart" > wrote in message
> > > news:opwwc.8392$HG.7233@attbi_s53...
> > > > "Jay Honeck" > wrote in message
> > > > news:ZFtwc.45447$pt3.6238@attbi_s03...
> > > > > > The J-3 didn't. I believe one of the Chief's didn't. I think
> mixture
> > > > > > was an optional item on all the 40's 65hp planes. Even when you
> had
> > > > > > mixture, it didn't do anything on the ground. It only effected you
> at
> > > > > > cruise power.
> > > > >
> > > > > Thanks, all, for the info about mixture-less aircraft. I've only
> flown
> a
> > > > > Cub once, and (apparently) never noticed the lack of a mixture
> control.
> (I
> > > > > don't think I ever touched the throttle -- the guy in back was
> working
> the
> > > > > power...) And I sure had no idea that this feature (or lack
> thereof)
> was
> > > > > universal to so many small-engined, older airplanes.
> > > >
> > > > There's a few features that older aircraft don't have. Some with the
> > > > Stromberg (?) carbs have them safety wired fully rich and use the mag
> switch
> > > > to shut down. It's kind of like shutting off a computer by just
> pulling
> the
> > > > power cord out of the wall.
> > >
> > > Actually it is like shutting off your car. Not a big deal by any means.
> >
> > Just don't touch the prop aftewards (unless you want it to start).
> > When I had the Chief we had to shut it down with the mags. Usually a
> > 20 degree turn on the prop was all we needed to hand start it. Now, if
> > some line guy were to "move" the prop, he'd have a hand full of his
> > hands (if the mags didn't ground). At least with a mixture airplane
> > you shouldn't have as much fireable fuel in the cylinders.
> >
> > -Robert
>
> I wouldn't bet a plug nickel on your last statement.


I wish you'd bet more because I want to get a new GPS for my plane. I
can only speak from years of owning a Chief with no mixture control.
Shutting down (with mag switch) putting gas in, turning the mags back
on, and turning the prop 1/8 turn (no starter), jumping in and flying
away.

-Robert

[[email protected]]

Robert M. Gary > wrote:
:> I wouldn't bet a plug nickel on your last statement.


: I wish you'd bet more because I want to get a new GPS for my plane. I
: can only speak from years of owning a Chief with no mixture control.
: Shutting down (with mag switch) putting gas in, turning the mags back
: on, and turning the prop 1/8 turn (no starter), jumping in and flying
: away.

Certainly believable with impulse couplings. They fire *after* TDC, and are
spring-loaded to have good spark. If there's burnable fuel in the cylinder, a slow
prop turn past the mag *click* could certainly light it off.

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[G.R. Patterson III]

"Robert M. Gary" wrote:
>
> "Dave Stadt" > wrote in message >...
> > "Robert M. Gary" > wrote in message
> > om...

> > > Just don't touch the prop aftewards (unless you want it to start).
> > > When I had the Chief we had to shut it down with the mags. Usually a
> > > 20 degree turn on the prop was all we needed to hand start it. Now, if
> > > some line guy were to "move" the prop, he'd have a hand full of his
> > > hands (if the mags didn't ground). At least with a mixture airplane
> > > you shouldn't have as much fireable fuel in the cylinders.
> >
> > I wouldn't bet a plug nickel on your last statement.
>
> I wish you'd bet more because I want to get a new GPS for my plane. I
> can only speak from years of owning a Chief with no mixture control.

I think you should reconsider. The "last statement" there was something to the effect
that an aircraft with a mixture control wouldn't have much gas in the cylinders after
being shut down. While you are correct that it "shouldn't" have, Dave's point is that
it isn't a good idea to count on that being the case. He isn't about to bet on the
engine not starting (or at least kicking) when the prop is moved.

George Patterson
None of us is as dumb as all of us.

[Dave Stadt]

"Robert M. Gary" > wrote in message
m...
> "Dave Stadt" > wrote in message
>...
> > "Robert M. Gary" > wrote in message
> > om...
> > > "Dave Stadt" > wrote in message
> > >...
> > > > "G. Burkhart" > wrote in message
> > > > news:opwwc.8392$HG.7233@attbi_s53...
> > > > > "Jay Honeck" > wrote in message
> > > > > news:ZFtwc.45447$pt3.6238@attbi_s03...
> > > > > > > The J-3 didn't. I believe one of the Chief's didn't. I think
> > mixture
> > > > > > > was an optional item on all the 40's 65hp planes. Even when
you
> > had
> > > > > > > mixture, it didn't do anything on the ground. It only effected
you
> > at
> > > > > > > cruise power.
> > > > > >
> > > > > > Thanks, all, for the info about mixture-less aircraft. I've
only
> > flown
> > a
> > > > > > Cub once, and (apparently) never noticed the lack of a mixture
> > control.
> > (I
> > > > > > don't think I ever touched the throttle -- the guy in back was
> > working
> > the
> > > > > > power...) And I sure had no idea that this feature (or lack
> > thereof)
> > was
> > > > > > universal to so many small-engined, older airplanes.
> > > > >
> > > > > There's a few features that older aircraft don't have. Some with
the
> > > > > Stromberg (?) carbs have them safety wired fully rich and use the
mag
> > switch
> > > > > to shut down. It's kind of like shutting off a computer by just
> > pulling
> > the
> > > > > power cord out of the wall.
> > > >
> > > > Actually it is like shutting off your car. Not a big deal by any
means.
> > >
> > > Just don't touch the prop aftewards (unless you want it to start).
> > > When I had the Chief we had to shut it down with the mags. Usually a
> > > 20 degree turn on the prop was all we needed to hand start it. Now, if
> > > some line guy were to "move" the prop, he'd have a hand full of his
> > > hands (if the mags didn't ground). At least with a mixture airplane
> > > you shouldn't have as much fireable fuel in the cylinders.
> > >
> > > -Robert
> >
> > I wouldn't bet a plug nickel on your last statement.
>
>
> I wish you'd bet more because I want to get a new GPS for my plane. I
> can only speak from years of owning a Chief with no mixture control.
> Shutting down (with mag switch) putting gas in, turning the mags back
> on, and turning the prop 1/8 turn (no starter), jumping in and flying
> away.
>
> -Robert

I guess my comment went way, way over your head. What I am saying is that
if you think an engine shut down with an idle cutoff mixture control won't
have enough fuel in a cylinder to take off an arm you are kidding yourself.