Mounting a Saito 4 Stroke Upside down.

Kevin Welz

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Oct 15, 2001, 8:24:41 PM10/15/01

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Someone in my local Hoby shop today told me that it is bad to mount a 4
stroke Engine upside down on a plane. Well I am building a Aresti .40 and
decided to go with a Saito .56 instead of the MDS .48 I had before. Since
this kit requires the engine to be mounted upside down I am now a bit
worried. Should I be? Was this guy wrong or should I put the Saito on a
different plane?

Gord Schindler

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Oct 15, 2001, 8:29:19 PM10/15/01

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I have several FSs mounted inverted and have yet to see a difference. YOu
may have to mount the tank a little lower than when right side up but
otherwise should be ok.
Gord Schindler
MAAC6694

"Kevin Welz" <yeah...@aye.net> wrote in message
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Steve

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Oct 15, 2001, 9:00:24 PM10/15/01

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I wouldn't worry too much. Typically, you might have a higher and/or
rougher idle, but even that can be worked out with the right glow plug and
fuel. Worse case, a glow driver might be needed.

In all the inverted installations I had, only one required a glow driver.
With the others, I just needed to find the right combination of fuel and
glow plug, and it was fine.

Steve
medi...@mindspring.com
RC web Site http://webpages.charter.net/mediashop/rc-giant-scale/
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IronZ

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Oct 15, 2001, 9:07:44 PM10/15/01

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I've heard that you may have to get an onboard glow driver when mounting
inverted. I don't have personal experience, just something I've heard.

IronZ

--
AMA# 699497

"Aces High!"

"Kevin Welz" <yeah...@aye.net> wrote in message
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Martin X. Moleski, SJ

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Oct 15, 2001, 9:42:28 PM10/15/01

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"Kevin Welz" <yeah...@aye.net> wrote in message
news:J1Ly7.37926$6i7.3...@e420r-atl1.usenetserver.com...
> Someone in my local Hoby shop today told me that it is bad to mount a 4
> stroke Engine upside down on a plane. Well I am building a Aresti .40 and
> decided to go with a Saito .56 instead of the MDS .48 I had before. Since
> this kit requires the engine to be mounted upside down I am now a bit
> worried. Should I be? Was this guy wrong or should I put the Saito on a
> different plane?

I've flown an inverted Saito .91 with no difficulty--well, no
difficulty from the engine. I buried the airplane. The engine
worked well all the way down.

Inverted four-strokes, the vast majority without on-boad glow,
are the norm in pattern competition. Planes have to meet
a 5 Kg (11 pound) weight limit. The guys don't want to
carry an extra battery around with them.

Marty

Six_O'Clock_High

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Oct 16, 2001, 12:02:28 AM10/16/01

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It is only a bad idea if you insist on using an electric starter and fail to
insure there is not a hydraulic lock! Then they break.

The only other consideration is that you will have to lean the low end out
more to get the mixture right for reliable idle. If you are careful with
your installation and do not put the fuel tank too much higher than the
carb, they start and run very well.

Six_O'clock_High
Targe...@guns.com

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John R. Agnew

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Oct 16, 2001, 5:09:03 PM10/16/01

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"Martin X. Moleski, SJ" <mol...@canisius.edu> wrote in message news:<204nstkc58h8vgq2f...@4ax.com>...

If you mount it upright, it will be inverted about half of the time
when flying, right? If you mount it inverted, it will be upright about
half the time when flying, right? Flying is not a problem. The guy who
writes about engines in MAN says that he always mounts his engines
inverted, does not use on-board ignition, and has no problems.
>
> Marty

skesler

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Oct 16, 2001, 6:10:59 PM10/16/01

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In article <ojOy7.3320$SU2.3...@newsread1.prod.itd.earthlink.net>,
Targe...@guns.com says...

Agreed, but if you will use a perry pump or Cline Reg. System, you will
not have to worry about tank location and will get a more consistent run.
This is one reason why the YS engines do well inverted in Pattern planes.
They have a pressure regulated fuel system built in. Plane attitude does
not matter, and neither does fuel level. I'm not saying a Saito will run
like a YS just by using a regulated fuel system, but it will prevent much
of the problems people have when inverting a 4 stroke without such a
device.
Steve

Robert McCoy

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Oct 16, 2001, 10:32:58 PM10/16/01

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I have a Saito .56 mounted inverted in a Dymond Tiger Moth. Runs
strong, and idles great too. Most of the time it putts around at 1/3
throttle, but I can throw it wide open for loops, etc. and it never
misses a beat on the transition.

I changed from the stock glow plug to an OS F which improved the idle
significantly. I also found that the idle goes much lower (~2400 rpm)
with a glass prop (Master Airscrew K-Series 12x6) versus the same size
wood prop. I understand the wood is too light to carry the engine
through the compression stroke reliably.

Don't think twice about mounting the .56 inverted, and let us know how
the Aresti flies!

"Kevin Welz" <yeah...@aye.net> wrote in message news:<J1Ly7.37926$6i7.3...@e420r-atl1.usenetserver.com>...

Tuomo Kokkonen

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Oct 17, 2001, 3:27:30 AM10/17/01

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The only problem that I see in inverted mounting is that the access to
engine, fule lines etc. is often limited.

rober...@sprintmail.com (Robert McCoy) wrote in message news:<2f29248f.01101...@posting.google.com>...

Mike

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Oct 17, 2001, 9:54:40 AM10/17/01

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I've ran my saito 120 inverted sense new and it works good. Just use an OS
F type glow plug. Use after run oil also.

Mike
Dayton, OH