MyWay

I would like to know what plane, engine, prop, muffler/pipe combinations extreme speed fliers have come up with that will yield speeds in excess of 150 mph for .15, thru .32 sizes only. Thanks.



,

Ed Smith

None!

Ed S

bob27s

My Feedback: (19)

Yeah, Ed is pretty close

As for a sport ship (no racing specalized) there are few combinations out there that can reach that mark. There are a few european speed ships that can get up to 150 with the right setup. Styrkas and some others over there might be able to point out a few.

The Kangke F3D was close with the Jett 35 up front.

The only one I know confirmed over 150 (radar) (per your post) was an older QM15 airframe with a Jett 30 installed in it. Im pretty sure it was an old Pole Kitty. No doubt any of the Matney QM15 aircraft or other QM15's still hanging around can get up in that range with similar power and the right prop.

The QM15's were were racing with the Nelson 15 in it were flying high single digits/ low teens on the short course if I recall last they competed. That sound about right Ed ?

Bob

MyWay

WOW!! Thats not what i want to hear.

slowmo777

Bob.R

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So, slowmo, how fast?

Ed Smith

That sounds right on the money Bob.

Actually I was trying to stimulate replies to the contrary. Speed claims are always good for a laugh!

Ed S

combatpigg

My Feedback: (3)

I don't know how to bring the link to a video over to here, but on page 4 at the 1/2A forum, there is video of 3 little racers. The thread is called "LEFT COAST RACING VIDEO", or something like that. The first plane is powered by a stock COX reed valve engine and is doing about 60. The second plane is a scratch built racer that I built. It has a glass fuselage and solid balsa wing. The engine is a piped G&Z .061 that I got from BILL HUGHES. With a 4.2 x 4 APC and 50% nitro, it tachs 42,000 rpm. It is too expensive to run that way, but the sound is priceless! In the video I have toned it down a bit for sport flying, it is running 15% BYRONs' and a 4.2 x 5 ELIMINATOR prop at 36,000 rpm. The plane has 124 sq " and weighs 14 ozs RTF. You can definately hear an unloading once airborne. On paper this set up is good for 170 mph, so be the judge if you see the video. The last plane in the video is a FORA .049 powered, scratch built roughly GUILLOWS dimensions] MUSTANG, belly scoop and all. It turns a 4.2 x 4 APC at 32,000 on 15% fuel. It also has about 120 sq " of wing, but it only weighs 11 ozs, so it is a nice racer around the poles. It would be fun to have a racing event for this little stuff, the CYCLONS and FORAS are easy to operate and inexpensive to run once you get past the initial investment, they just run and run.

[Editted to direct viewers to page 4 of 1/2A forum]

combatpigg

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[link]http://www.ulmer-rc.com/files/swr.wmv[/link]

See if this works, I've never done this before []!!!

Rebellion

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Works great for me. Here's a link to the thread. [link=http://www.rcuniverse.com/forum/m_3414330/tm.htm]Link[/link] Man, I gotta check out the 1/2 A forum more often!

MyWay

Combatpigg, Nice video. Looks like you really had your hands full flying the little birds. Looks like they would wink out very quickly if you did not fly in tight circles. Smaller is better to a point. If you can't see them you can't fly them. Thanks for the input.

.

combatpigg

My Feedback: (3)

The first time I ever launched it, I could not believe how small it got so quickly. On a bright day, it isn't too hard to see at normal flying distances. The controls are set for very slight movement and lots of mechanical advantage, so the plane grooves well. Just a pair of HS 55s doing all the work. The heaviest component by far is the engine at about 3 ozs, it is developing over 1/2 HP. We haven't clocked it yet, but it looks as fast as most Q 500s that I've seen. The C/L guys are getting almost 160mph with the same engine set up.

MyWay

Keep up the good work and get some numbers on that little guy.

Skull Man

Myway,

I build and fly a 1/12 scale mustang from combat design ...I believe it was originally designed for a .15. It has been modified with reduced scoop, small, low profile canopy...etc.

The nose has been narrowed to accept a 1 3/4" spinner......sweet!!! I shoved an OS .32 in it and used a Jett pipe. The plane weighs in at 2 1/4 lbs dry.

The engine/ pipe combo really likes the APC 9 x 5 prop. an 8x7 really gets it going but hand launching it is tougher.

I'm guessing the plane approaches the speeds your asking about......I don't have verified speeds but I would bet they are in the 140-150 range

MyWay

Skull Man. Sounds like you like speed. If you would like even more speed raise the exhaust timing on the .32 to match the tuned muffler and install an 8x8 prop. You should see approx 18000 rpm if done correctly. Hand launching might take a little getting used to.

combatpigg

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I haven't raised the timing of my OS .32, but am running it with a MACs' header and pipe. It puts out 18,000 on 15% nitro with either an APC 8x8 or 7.2x8.6. I have degreed the .32 and if memory serves correct, it is already sitting at 180 degrees of exhaust duration. The mustang is probably small enough to try the higher 8.6 pitch. THRUST HP says this combo could acheive 148 mph and develope 2.6 pounds of thrust. Higher nitro would put you over the top, just have some head shims handy before trying it. I fly my 2.5 pound DD this way and the launches are solid with the 7.2" prop.

kamakazie frank

My Feedback: (2)

Hey Combatpigg:

Have the same setup. Clocked at over 150 mph. Great performing plane, does almost any manuver - knife edges forever. The only problem I have is this plane won't slow down for a landing!

MJD

My Feedback: (1)

I'll take you up on that bet! On a 5 inch pitch prop, rpm for a pitch speed of 140 mph is about 29,500. 7 inch, about 21,000. Hey, you might be, but I'd have to see it to believe it. But I bet it is fast nonetheless.

MJD

combatpigg

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Thanks for showing your plane, KKF! She's a beaut! Now I know what I want for the .32 next, one of those! Could you pass on the critical dimensions? [I hate kits]

Man, A HOTS and a nice .30 sized speed plane, what more could you want ?

MyWay

Combatpigg. The stock os .32 exhaust timing is not close to 180 degrees but a tuned pipe still works very good. I thought that we were talking about the jett tuned muffler which will not give you much of a rpm increase unless the exhaust timing is increased. With the timing set right just about any .32 will run apc 8/7, 7.2x8.6 or 7.4x8 carbon fiber over 19000 rpms. All three props have about the same loading. The tuned pipe has about a 500rpm gain over the jett muffler. Engines that have a small exhaust and better match up with the jett muffler get better results. A webra has a good exhaust matchup with the jett tuned muffler. A webra 25 kicks butt out of the box, however, a slight adjustment to the timing and this little monster would run 18300 rpm with the jett muffler with a apc 8/7 and 19400 rpm with a 8/6. Sorry about the misunderstanding.

combatpigg

My Feedback: (3)

MYWAY, It could have been the OS .15 CZ that I measured then, but one of these 2 engines comes stock with pipe timing. I ended up putting a homemade header on the .15 with a MACs' pipe, and it is sporty fast with a 7x5, but that's about it. I should treat it to a 6.5x6.5 and see what happens. If raising the .32s' port a little is all it takes to gain another 1000 rpm, then that is time well spent. Some engines only need to have the center third of the port raised, which would be a cautious way to approach any porting. I think that a CYCLON .15 could get a plane into the 150s, this is the engine that put all the other competition .15s in the want ads.

MJD

My Feedback: (1)

Mmmmmmmmm, those are some demonic rpms's yer running there! Love it!

One or two minutes of that per flight should be about enough..

MyWay

Combatpigg, The OS tz-t 18 is the same size case as the 15 and will pull a 7/6 apc over 20000 rpm without the tuned pipe. It shows a lot of potential. Can't wait to get a tuned pipe set up and try a 7x7 prop cut down to 6 1/2 dia. Couple this motor in a 24 oz. plane and hold on.
.

combatpigg

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MJD, the G&Z engine really makes you pay for those extra rpms, I have gotten an average of maybe 15 minutes to a 1/2 hour from each P/L set. The replacement sets are $30. A broken off hunk of glow plug element is always the culprit. Now that it has been detuned from 42,000 [to about 36,000] the life span of the parts has doubled, but no where near as trouble free as a CYCLON or FORA, which put out enough power to be scary already. I've put several hours of run time on the FORA and have never even had the head or backplate off. It sure is cool to hear an engine with a frequency of 700 cycles per second! How can that be possible?

MYWAY, have you ever been to the CYCLON site and seen their photo essay about how those engines are built? Pretty impressive!

Skull Man

O.K. here is the last one I built.



What do you mean raise the timing...or should I ask how?