Building a 1/4 cosmic wind and Im gonna use an rcgf 21 twin.....the engine alone fits very nicely in the cowl but the muffler cans are really gonna cause a fitment issue................im not at all concerned with having a loud plane soooo...............just curious if anybody out there has ran the 21 twin with straight headers??.........im thinking either straight down or bent back slightly is gonna be my best bet for easy fitment without chopping up the cowl.......................any input.........a video would be awesome

Noise would be an issue for me, even if it were not for the area/club/flying field I'm flying with.

Open exhaust 2 stroke is just about the most obnoxious sound there is.

What's up with that..............duuuh...obviously it's gonna be loud...its a race plane...i don't care about it being loud....the louder the better......if you don't like it then your too old!!.......i didn't ask if anybody ever heard an engine with open headers....i asked if anybody has ran one with open headers and if they had performance issues or not......dont post your annoying comments about how the neighbor guy had a bad ass airplane that was obnoxiously loud....we don't care

Where did you ask about performance?

It's "I don't care about anyone but me" attitudes like yours that cost guys like me flying sites. Get a grip.... then do some homework. There's absolutely NOTHING to be gained by running an open exhaust on a 2 stroke anything. That's common knowledge that has been around longer than you've been breathing likely.

So, not only will most others consider your plane obnoxious, it'll get blown into the dust by anyone that's serious about going fast.

You sound like the only lessons you learn are done the hard way anyway. Go for it...

Hahaha...you know what they say about opinions.........im not trying to gain anything performance wise..... just trying to not chop up my cowl to fit a stupid muffler can that is not really a try muffler....its just a basic cheap Chinese attempt at an expansion chamber...no baffle at all...............again im not asking for your boo hoo attitudes........dont post them here please...theres countless threads with the same crap over and over about how "it's too loud".....i don't care grampa!...you guys can go back to glueing sticks togethor

And ya trust me buddy. If nobody has tried it...then I'll be the first.....if nobody ever tried the unknown we'd all still be cave men dude...........grow a pair!

If you could read, it has been tried.

This is absolutely rediculous RCG....really......comical....i think I'll leave the thread open........i could report every one of this guys posts on this thread for trolling, Ha! .....trolling, more like harassment!

Here are my thoughts,,,

Do you have headers that are going to work? Most that I've seen pretty much go straight back, I don't know of any that are effectively just exhaust stacks, so you may have to custom make them. In all reality what you are gaining from open headers is maybe a cleaner look on he bottom of the cowl. You won't really gain much in aerodynamics by avoiding the cut-out that is needed to accommodate the mufflers.

I've run the RCGF 21cc twin in a Seagull pylon racer. It did not have the rpms to really get the air speed up. I'm now running it on a 60" Skybolt biplane.

The mufflers on RCGF engines are essentially straight through (no baffling to lower the sound. So the engine should run on straight pipes.

I don't think that the claim of 14 pounds of thrust is right. Although the twin runs very smoothly (almost no vibration), I think that the pounds of thrust is less than the other 20cc gas 2-strokes.

Good luck.