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<DIV><FONT size=2>15-10 is an excellent prop on the 120SC, if its a strong one
you can with the 15-11</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Of special note the 120SC likes Nitro. It is a fairly high
compression engine and can be a little finicky. It was the strongest of the
120's In fact I had one that gave the 140FZ a run for the money.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Being this soupped up highly tuned 120...the extra nitro
broadens the mixture settings. The other thing it does is higher nitro require
richer settings to get the mixture correct and as a result they will run a bit
cooler and better. More fuel flow means more oil flow and better cooling
also.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I strongly recommend the Cool Power 30% heli
fuel.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>By the way, on the 120SC because its more a higher compression
soupped up version, don't run it out of fuel. If you are flying and too long and
the engine runs dry it can backfire and can cause damage. Its never a good idea
to run any of the pattern engines 2 or 4 stroke out of fuel, however the 120SC,
120AC, and the 140DZ tend to be a little brutal when this happens. Try to run
the 120SC at the higher end of rpms. I would say the goal rpm for that engine
would try to be up at 8600-8800 maybe as high as 9000. On the 15" props it will
make noise with ease in most cases(read exhaust systems)</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>The 120SC is an awesome engine. Like I said it was the king
the of the 120's. There were some folks that had issues with them, but my
experience was always good with the SC. There were some piston of the month
changes to the 120SC. Namely they had a dished piston, and some magnesium
pistons. The goals behind these were to get more power out of the 120 case. Back
then the FAI rules had not changed to allow larger than 120 displacement. So YS
was trying to lighten the piston, and get the engine making max power from the
little box. At the time there were a few models that were getting bigger than
the 2 meter box as the 2m box didn't exist. No size limit just the engine limit
and the weight limit existed at the time. On the piston front just stick any ole
120 piston in it....the 120SC piston could be a little fragile if run lean
(meaning running it out of fuel). The original 120SF piston was bullet proof and
works in the 120SC. The dished and designer pistons are really able to change
the behavior of the engine. I have played with this "super" or
the "hyper" pistons on the current 160DZ and 170DZ engines. Its cool
how changing the piston by putting a dished top and closing off the bottom of
the piston can change the way the engine reacts to certain prop loads, or it
will change the noise. Some of the things they can do make more power and some
of the pistons make it run super smooth and quiet. Yamada doesn't do the testing
in production like they once did with the pistons. I have been fortunate to try
some of the super cool, "hyper" pistons they have played with on the DZ's. I
wish I had the knowledge back then that I have now. Some of the smallest changes
in a piston can really totally change the way an engine performs. Its kinda
neat. I remember the need was for more power more power back then and now I know
which piston designs would have done it better. </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Any of the current exhaust systems will work very well on the
engine. Even the short hatori 821 pipes and the NMP header will work excellent
on that engine.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I have a couple of 120AC's that we carved up the heads to
get more power...I wish I still had the 120SC as it would be a really good
engine for my war bird project I'm planning. I actually need a pair of the
120SC's for it. Right now the 120AC's are a little heavier than I would like and
have been considering putting a pair of 140 Sports in the model.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I know this was likely way way more information than you
needed to know. But its a good engine and you'll love it.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Troy Newman</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=flyintexan@comcast.net
href="mailto:flyintexan@comcast.net">flyintexan</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 29, 2007 8:53
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] YS 120
NC/SC prop recommendation</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Should be able to run a 16x8 on
30%...</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=paul.horan@sbcglobal.net
href="mailto:paul.horan@sbcglobal.net">Paul Horan</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 29, 2007 6:09
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [NSRCA-discussion] YS 120
NC/SC prop recommendation</DIV>
<DIV><BR></DIV>
<DIV> Any suggestions for a YS 120 prop ? It will be on a Aires
?</DIV>
<DIV>Thanks,</DIV>
<DIV>Paul<BR></DIV>
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