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Engine basics => Engine set up tips => Topic started by: phil myers on March 20, 2014, 01:30:34 PM
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use muffler pressure or not, Hi All, I've had this SC 25 for a few years now, never used it before but its going in a Flite Streak which has a standard wedge tank (one pipe up and one pipe down plus the feed) I don't know if these motors run better with a muffler pressure pipe.. This plane weighs 29 oz, do you think a 9x6 prop is the right size? I'm thinking it might be quick! Thanks Phil
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What's an SC 25? engine? Anyway, 6 pitch will probably be too fast for stunt. 9/4 or 10/4 will help keep the speed down. Along with the right size venturi. Probably somewhere in the .250-.270 range with a conventional needle valve.
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Hello Phil,
SC engines are Chinese mainland production and the SC stands for Super Custom. There are a few other makes that look identical to SC depending where you are in the world. The usual meaning of SC would be a little unkind for these engines. OK they are super cheap but improving in quality. Not to be confused with CS engines which really are what you think CS stands for!
Regards,
Andrew
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If it's an OS clone, why don't you look at the advice for the LA 25 and start with that?
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Try it both ways, see which way works the best. :! Every engine is different, no "one size fits all" rule. 8)
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Magnum, ASP and SC's are all different brands of the same engines. Not bad engines. I ran a Magnum XL .25 some years ago with a .257" venturi, .156" spraybar, 10% nitro/22% blend oil, and a 9-4 Taipan prop. That was about right for sport stunt. I recall trying some other props that didn't work as well. I think the 9.5 x 4.5 APC might be worth a try. The 10-3 and 10-4 (maybe) didn't work. I had it on a Pat Johnston "Stunt Trainer" that Jimmy Johnson gave me. It crashed. I don't remember exactly why, but it was at Fort Dent Park...a nasty, turbulent place,...so we'll just say it was turbulence from the trees. LL~ Steve
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Thanks for the info on props guys.. Tim, I put LA25 in the search box and wow! there is a few thousand hours (maybe slight exaggeration there) of reading there. I'll do a few test flights regarding the muffler..
Ta Phil
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Phil,
I may be wrong here, but I am pretty certain that the SC25 is not an LA25 clone.
Regards,
Andrew.
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Phil,
I may be wrong here, but I am pretty certain that the SC25 is not an LA25 clone.
Regards,
Andrew.
Absolutely. It would be a sorta clone of the OS .25F, aka "FSR", a fairly hot twin ball bearing design. H^^ Steve
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Andrew, Steve, I had my doubts about it being a 'clone' of the la25 but wasn't sure, so thanks for the clarification..this plane weighs 29 oz with this motor and the muffler, so I'm guessing it'll be fairly zippy through the air. I hope to fly this on more windy days.(which we have a lot of!)
Thankyou Phil
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Hi Phil,
It sounds like you have good advice on the SC 25. Don't expect 4-2-4 style run, go for wet 2 stroke with the 9-4 prop.
Folks have used engines like the SC 25 for speed limit combat (ASP or Magnum versions of the engine). That would be with a 8-4 prop and bladder pressure tank.
-Chris
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Thanks Chris, I flew the Flite Streak for the first time yesterday ( in fact 1st time out since last October) and all seemed fine, 9x4 and muffler pressure but after the 1st and only flight the engine was very stiff to turn over so a friend has offered to strip it down to see what the problem is, I wait 5 months to get out for some fun and this happens. Jeez! Phil
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OK, now I get it. SC is another brand name from Sanye Precision Machinery in Shenzhen, China.