Need help with OS33 Setup: Pipes & Without

[dth7]

Don't want to take away from Joe's nice build but I think I found a first gas 78" Extra! No pics but it sounds like a bit of a "franken extra" with one blue and one red wing (I guess the red wasn't in stock when he replaced it). All servos, Rx and tuned pipe included. I don't really mind the mismatched wings since this will be the learning curve/ beater bird. I can move it all to a new Airframe later once I get used to the whole gas thing. I want to put an OS 33 on it. Anyone have any info on the OS33 and tuned pipe install (header) and break in? Didn't see another appropriate forum for that.

Thanks and Joe, I'm jealous, looking great!

Gyro, feel free to move this to a better place. If there isn't one maybe we can start a new one- OS33 set up with and without tuned pipe. Thanks. Sorry for cutting in Joe.

 

[gyro]

moved per your request! I'd PM Quadracer, as he has an OS engine I believe.

 

[dth7]

moved per your request! I'd PM Quadracer, as he has an OS engine I believe.

Thanks, didn't want to start a new one if one was there and I wasn't seeing it. Check my post in your bought a few planes blog! got a little self therapy in!!

So, Anyone out there running the OS GT 33? I'm going to put it in a EF 78" Extra with a composite tuned pipe. So far I have found headers (side to rear center) at Mile High and Hatori. Looking for feedback on props, break in and performance. I will update as I learn more. Looking forward to first gasser!

 

[dskuro95]

Hey DTH! I don't have an O.S. GT 33 but I do have a friend with one and I have very big suggestions for you! If you wind up using the muffler it comes with since it has that smoke black paint on it where it bolts on strip that off where it mounts. Do this because that eventually chips and makes your muffler come loose and you have a chance of losing the bolts and all. Loctite it after you peel that off as well. If you want the plane really quiet I suggest the 20x8-10. If you aren't as worried about noise I recommend the 19x10 or 20x10. I have a mejzlik 20x10 undrilled that I can sell you.
Hope this helps you out!

dskuro95

Thanks, didn't want to start a new one if one was there and I wasn't seeing it. Check my post in your bought a few planes blog! got a little self therapy in!!

So, Anyone out there running the OS GT 33? I'm going to put it in a EF 78" Extra with a composite tuned pipe. So far I have found headers (side to rear center) at Mile High and Hatori. Looking for feedback on props, break in and performance. I will update as I learn more. Looking forward to first gasser!

 

[hone]

Funny that i'm going to be the one to revive this thread.

Picked up a OS 33. So far i'm running a 19x8 xoar but i'm looking for a Hatori #2301 header to go with the ES35G composite pipe i just bought.

Here is some info i got on the setup from another guy, " I have a Hatori #2301 header on mine (RTC type) with a 4 1/2" extension added. The minimum distance between exhaust port flange and reflection baffle is 27". I turn an APC 20 x 10.5 PN at 7400 rpm. I've played with various lengths and there is very little difference anywhere from 27" to 30". Pipe length is considerably less critical in a gasoline/CDI set-up because the CDI timing provides the spark. Unlike glow 2 strokes, the pipe resonance has a wider window and simply adds both rpm and torque. BUT, I wouldn't go to any shorter length than 27", straight line. Silicone turbo hose works fine as coupling material. Holding on is often a PITA. I install 3, 6-32 x1/8" button head screws on the header and pipe stems under the coupler (that's Ed Skorepa's idea) and that holds couplers on much better. Teflon also works fine but will leak over time."


Also, he said he uses AVgas and that when he uses premium auto gas he gets 300 more RPM.

 

[Enterprise]

Avgas (100LL) has a ton of lead in it to get the octane up that high. These type of engines will eventually foul the plug using that fuel. I used to own a full scale plane that eas designed for 80 octane Avgas which has 1/4 the lead of 100LL and I mixed it with pump fuel (pre ethanol) to get a decent fuel that did not foul the plugs up all the time. Now this was in a 108 hp Lycoming.

I personally use 91 octane ethanol free auto gas I get at the local airport with 50:1 HP Ultra synthetic oil.

 

[hone]

I was going to go with 91 octane(i heard chevron premium is ethanol free?)and redline synthetic 40:1. I'm going with redline because it's available locally and i heard it was good. My buddy uses Stihl HP Ultra at 50:1 also and likes it very much.

 

[Enterprise]

I would normally say check out this site.

http://pure-gas.org/

But I see that the closest is over 2 hours from you. I also checked airnav and the closest airport is a seaplane base over a hour away.

Check local Marinas as they also sometimes have ethanol free gas as boats sit a lot too.

 

[hone]

Is teflon tube and spring clamps going to be my best best for securing the pipe to the header?

How hot will the exhaust get?

Are there any other options you would suggest besides the teflon and spring clamps? And what is the tape i see people wrap the teflon couplers with?

 

[Racerman27410]

Is teflon tube and spring clamps going to be my best best for securing the pipe to the header?

How hot will the exhaust get?

Are there any other options you would suggest besides the teflon and spring clamps? And what is the tape i see people wrap the teflon couplers with?

this works very well as long as surfaces are nice and clean when you wrap the pipe...

http://www.rescuetape.com/