Just bought a Seagull Edge 540 60. Using a Super Tiger 90. Anyone know about pitts style mufflers for this combo? I looked at a Bisson 2176 or a Slimline 6002U . There's not much room in the cowl and I dont want to cut it up unless absolutely necessary. Any suggestions ? Anyone using the stock muffler and mounting the engine at an angle? Thanks
Prop Seagull Edge 540 muffler
- Thread starter 427jimmy
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Tony
Staff member
The Pitts style muffler is a MUST on this plane. I can't stand it when I see one with the stock muffler hanging out the side. I think there are two different styles of Pitts mufflers out there, one where you mount the engine horizontal with the exhaust port facing the bottom, and one where you mount the engine inverted. But again, you must use a pitts muffler on this plane. Love the Edge lol.
Yes Tony I agree. When I flew earlier we used to fly CGM Extras and Ultimates . We always replaced the cowling with a fiberglas unit . The brand we used offered an extended bottom to clear Pitts style mufflers. They looked and worked great. In my opinion mounting a glow engine inverted is not an option, creates more problems than it solves. This Seagull cowl is shallow in the front and I'm concerned than ANY muffler with a side mount will hit. I was hoping someone had this airplane / engine combination and had a solution. I found dimensions for the Bisson 2176 muffler and am in process for the Slimline 6002U dimensions. Both of these mufflers have the outlet tubes swept back to help with cowling clearance. The main body of the muffler is the problem. I'm hoping one of the units has a small enough body to clear the cowl.
Hi Guys Still researching about my muffler situation. I have been talking to Slimline and they let me know they are coming out with a new Pitts muffler that has a triangular shaped canister to help with clearance on the models with raked cowls. I ordered one today. I will let you know about when it arrives. Jim
Adam any glow engine mounted inverted runs the risk of burying the element with oil and fuel. This causes idle quality problems , also causes throttle transition problems. Priming and choking the engine for starting is more difficult as the fuel runs out rather than into the engine. You can run a hotter plug but this can cause timing issues with the engine affecting power output and running temperature.
You can turn the aircraft upside down for priming , choking, starting and right it once running . Like I said, in my opinion, just not worth the hassle.
You can turn the aircraft upside down for priming , choking, starting and right it once running . Like I said, in my opinion, just not worth the hassle.
After a couple cell calls and some forum searching I found a muffler that works perfectly!! Bisson makes a modified unit specifically for Extra/Ultimate style cowlings. The part number for the ST 90 engine muffler is 2176. I has the muffler can and the outlet tubes shifted rearward . Makes for a great fit , no butchering the cowling . Bisson builds this style muffler for several engine makes.
There are a few things to know about the nature of setting up and running any engine inverted. RC engines are small, lightweight and fairly simplistic engines. They do not have all the complex equipment available to competition aerobatic full size aircraft engines or similar machines; therefore, when asked to run in inverted mounting, sometimes they can be a bit more challenging to set up than an upright installation.
First, realize that your engine may be full of fuel PRIOR to starting, risking hydrolock which can do severe damage to your engine, especially if the aircraft has been stood on its nose or even just nose low during transportation. Always flip the prop over to check the compression prior to using a starter. If it seems harder than normal, remove the glowplug and flip through several times or spin the engine with an electric starter to clear it and avoid the possibility of hydrolock.
Next, ALWAYS follow your manufacturer's instructions on engine break-in. In almost every case, the engine should be broken in on a test stand where it can be properly watched, cared for, fueled, drained, and adjusted easily and safely. If your manufacturer recommends in flight break-in, just be aware that it will be soft on power until the break-in period is completed and always be prepared for a dead stick landing during those break-in flights.
Then, once it is broken in, it can be installed. Please note that it is best to try to locate your engine so that the needle valve is in line with the centerline of the fuel tank if possible.
In some cases tuning in the inverted installation is a little more challenging due to the tank/carb relationship combined with the inverted mounting. If this is the case, tuning with the aircraft inverted/engine upright will help get the engine running flawlessly, then it can be run inverted.
Finally, some engines, especially inexpensive bushinged budget engines, will not like to start in an inverted position, again due to carb/tank positioning and fuel flow. In those case, you may need to start the aircraft inverted and turn upright to fly when running.