An OS 120 Exhaust question
10-16-2009, 06:38 AM
#1
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An OS 120 Exhaust question
This is the problem: I have to destroy 1/2 airplane nose to install the engine on it if I want to install the complete exhaust system. What if I use only the manifold (without muffler)? I don't care about noise since I fly in the middle of the nothing; just want to know if the engine could breaks or malfunction...
Thanks on advance.
Guille
Thanks on advance.
Guille
10-16-2009, 10:38 PM
#3
RE: An OS 120 Exhaust question
ORIGINAL: MinnFlyer
Most 4-stroke will run fine with no pressure, You'll just have to richen the mixture a bit.
Most 4-stroke will run fine with no pressure, You'll just have to richen the mixture a bit.
) Have fun.
10-17-2009, 04:57 PM
#5
RE: An OS 120 Exhaust question
You didn't say if your OS 1.20 FS has the pump or not. I've run my pumped OS 1.20 and .91 FS engines, both with pumps, without mufflers for the same reason - appearance and to avoid destroying half the cowl. Both engines ran great after tuning them.
On my Corsair I cut the angle of the exhaust pipe at an angle, and extended it outside the cowling about 1/2" to avoid filling the engine compartment with fuel residue and heat. Looked great, and sounded awesome. But beware of the law of unintended consequences!
The exhaust that exits a straight pipe is much hotter because you don't get the cooling benefit of the muffler. After only 4 - 5 flights, that hot exhaust which was blowing about 2 1/2" back onto the epoxy joint holding the wing panel to the belly pan, melted the epoxy. The result would have been disasterous if an observer hadn't noticed a rapidly growing space between the wing panel and belly pan. I quickly landed, and just in time. I'm currently in the process of building a new wing (I can't trust that glue joint now), and chopping up a beautiful cowling so that I can install the muffler.
Mike
On my Corsair I cut the angle of the exhaust pipe at an angle, and extended it outside the cowling about 1/2" to avoid filling the engine compartment with fuel residue and heat. Looked great, and sounded awesome. But beware of the law of unintended consequences!
The exhaust that exits a straight pipe is much hotter because you don't get the cooling benefit of the muffler. After only 4 - 5 flights, that hot exhaust which was blowing about 2 1/2" back onto the epoxy joint holding the wing panel to the belly pan, melted the epoxy. The result would have been disasterous if an observer hadn't noticed a rapidly growing space between the wing panel and belly pan. I quickly landed, and just in time. I'm currently in the process of building a new wing (I can't trust that glue joint now), and chopping up a beautiful cowling so that I can install the muffler.
Mike
