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Enya 30ss and Jettstream muffler

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Old 09-24-2011, 04:40 AM
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1QwkSport2.5r
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Default Enya 30ss and Jettstream muffler

I picked up a NIB Enya SS30 BB engine, and I'd like to put a Jett stream muffler on it. I looked on the Jett website and based in my measurements, the .25-.32 pipe should fit. (I measured 35.5mm bolt spacing but this is approximate) I'm a little strapped for cash at the moment, so I cant break the engine in on the Jett muffler. If I break the engine in on the stock muffler, what prop should I use to get the rpm up high enough so it turns up on the Jettstream? The guys in the glow engines forum all said to use a 9x6, but I believe thats the flight prop and I know Jett recommends for their engines to use a prop with the same pitch but 1" less diameter running rich at the rpm the engine will turn at. There isnt much information available about the SS30 engine, but what I did find was a figure of 13,500rpm on a MA 9x6 using 5% nitro. I know the Jett muffler will boost the rpm by at least 1000rpm, so if I want it to turn around 16,000rpm using the stock muffler should I use maybe an 8x6 or 8x5 for break-in? This is a Lapped iron/steel liner engine so its gonna need to run sickly rich for awhile before letting it turn up. I have a 10x6 MA prop that I cut down to 7.5" long for my TT .46. Could I use this instead of buying a dedicated small dia. prop?
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Old 09-26-2011, 07:32 AM
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Default RE: Enya 30ss and Jettstream muffler

Hi, sorry for the delay replying.....

Just put it on the test bench and break in the engine as you normally would. Enya makes an awesome engine.

I would suggest just using a 9x5 or your cut down 10x6 for break-in. The 9x6 would work just fine too, but personally I would go with the 9x5 to start with. It need not be big soaking rich. First run at the 2-4 cycle break sound. Just a few minutes like that will do. Then take it to a clean 2 cycle, still rich of course, but let it run.

The rpm will not be a huge factor. Just run it in and do not over prop it. After 4-5 tanks of fuel put a 9x5 or 9x6 on it and find peak rpm - just as with any engine, briefly find the peak, back off 500 rpm from the peak and just get use to it. If you have a tach, get some baseline RPM numbers.

I would target a prop selection that will let the engine find a peak ground rpm around 14,000. The 9x5 should get you there.

When you put the jett-stream on later on - you will see the rpm jump, and you can compair to the baseline you had when originally broken in.

Bob
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Old 09-26-2011, 02:33 PM
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Default RE: Enya 30ss and Jettstream muffler

Thanks for the reply, Bob. The only reason I bring up the rpm bit is based in part to my thunder tiger that is a little down on rpm. I went with advice from the glow engine forum to run a 10x6 for break in and I think it was too big a prop. The rpms have been steadily coming up on this engine. 16,800 on a 9x7 APC which is up from 16,400 a couple months ago.

I will toss it on the stand in a week or two and let it run and get some baseline rpm figures. Hopefully by spring I can get a Jett muffler on it and run it again before stuffing it in a plane.
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Old 09-29-2011, 12:35 PM
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Default RE: Enya 30ss and Jettstream muffler

Sounds good...

Breaking in an AAC or ABC engine -yes you want to run in at the target rpm, but under ligher loading and close to normal operating temperature and just slightly rich. Ring engine is different... start off rich and sneak up on the rpm.

The TT sounds like a good running engine. My TT40pro engines I use for racing run around 16,500 on average with a 9x6 and the stock muffler. Cool dry day and the right phase of the moon one of them pushes 16,800.

Let me know how you make out with the Enya
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Old 10-01-2011, 07:58 AM
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Default RE: Enya 30ss and Jettstream muffler


ORIGINAL: bob27s

Sounds good...

Breaking in an AAC or ABC engine -yes you want to run in at the target rpm, but under ligher loading and close to normal operating temperature and just slightly rich. Ring engine is different... start off rich and sneak up on the rpm.

The TT sounds like a good running engine. My TT40pro engines I use for racing run around 16,500 on average with a 9x6 and the stock muffler. Cool dry day and the right phase of the moon one of them pushes 16,800.

Let me know how you make out with the Enya
I'm going to run the Enya today sometime, and hopefully get a good start on the break-in. The general break-in idea I get from some of the other guys here is Lapped iron/steel liner engines and ringed engines get broke in similarily, very rich and WOT. Lapped iron - let it cool down between runs, with subsequent runs slowly leaning the needle down (ever so slowly). Seems a lot of guys swear by sloppy 4-stroking rich first couple runs (ringed/iron-steel) and slowly leaning it down so after an hour or so they're pretty well set. I've been a car guy for 14 years (all ABC engines) and just in the last year getting a few aircraft engines. Breaking in car engines is a little different since there's no fan on the front of it cooling it down and loading it enough to get the rod ends and piston seated.

My SuperTigre S90K wasnt new when I got it, but ran on the bench for less than a tank and what looked like low throttle. (ring was still almost all black/dark gray) I ran it 4-stroking rich at WOT using a 13x6 prop and the ring was fully seated after 1 16oz tank and over 2 more 16oz tanks I gradually leaned the needle down. This engine has phenomenal compression. Enough that it will tolerate 5% nitro but just barely. It turns 600-800rpm faster on 5% than it does on FAI fuel, but the idle is less consistent on FAI. Whats your take on that? I'm still pretty green with all the different types of aircraft engines so I ask around a lot.
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Old 10-03-2011, 05:26 AM
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Default RE: Enya 30ss and Jettstream muffler

ST engines are pretty much designed to run on any fuel you throw at them. I run all of my engines on either 10% or 15% (what ever is handy), including the ST engines ring, ABC, what have you. My only preference is to run fuel with a little castor in it, such as Omega.

Nitro always helps with idle. More consistant cylinder temperatures. In colder weather, going to higher nitro helps all aspects of the engine performance.

Don't over think the break-in process. For most engines these days, a few tanks on the bench and they are ready to go. Ring or non-ring - all about the same.

These are not 1965 Fox .35 engines anymore
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