OS46VXDF Pipe Question
12-21-2002, 02:31 AM
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OS46VXDF Pipe Question
Does anyone have a part number or know where I can get a tuned pipe for an OS46VXDF? :stupid:
Also, what's the best prop for this engine, 28K RPM seems like it would have to be a small prop to get to peak.
Also, what's the best prop for this engine, 28K RPM seems like it would have to be a small prop to get to peak.
12-21-2002, 05:56 PM
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VXDF pipe..
Rick, I don't know what the OS pipe part # would be, and you know that some of the fan pipes are kinda strange with the outlet coming out the side and stuff.
I had the best luck on the VRDF with a Nelson FAI pipe, and that's what I'll use on the VXDF..I haven't ran it yet..
As for props...well, you are on your own. I ran a 7.4 X 8.25 CF prop on the VRDF, turned about 22K static. Maybe 24K or so in the air. But it would appear my thinking was flawed, guys are getting more speed from larger diameter, less pitch props making me think that these little props don't have enough thrust to fly anything but a real slippery Q40 plane or something along those lines.
And 28K is the upper end of the practical RPM range, so I guess you will want a prop that will turn that unloaded, so now the diameter comes back into play via tip speed, so I have no idea what to use, and am in the same boat as you.
I had the best luck on the VRDF with a Nelson FAI pipe, and that's what I'll use on the VXDF..I haven't ran it yet..
As for props...well, you are on your own. I ran a 7.4 X 8.25 CF prop on the VRDF, turned about 22K static. Maybe 24K or so in the air. But it would appear my thinking was flawed, guys are getting more speed from larger diameter, less pitch props making me think that these little props don't have enough thrust to fly anything but a real slippery Q40 plane or something along those lines.
And 28K is the upper end of the practical RPM range, so I guess you will want a prop that will turn that unloaded, so now the diameter comes back into play via tip speed, so I have no idea what to use, and am in the same boat as you.
12-23-2002, 04:56 PM
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OS 46 VXDF Pipe
The recommended pipe for the OS46 VXDF is the MACS #1250 8.5cc muffled tuned pipe. At least thats what it is for use in at Turbax ducted fan and spins on the order of 23,000 RPM. Check with Larry Wolfe at Jet Hangar Hobbies . He can tell you the correct pipe length, which coupler to use, etc.
12-23-2002, 05:54 PM
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Thanks...
For the link...I got a 1250 with the engine, that's what the guy had bought to use with it. I'm glad to see it is working on the jets, I'll feel better about trying it now. I know the Macs 7.5 cc pipe won't work.
12-29-2002, 06:44 PM
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OS46VXDF Pipe Question
Another option which I use for this engine in a ducted fan is the Weston UK mini pipe. It will give a few hundred more RPm than the Mac's pipe and is a bit quieter. Also, no pipe hanger is necessary. Contact JD Enterprises for details. http://jdenterprise.net/
12-30-2002, 03:34 AM
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OS46VXDF Pipe Question
I have a little experience with running props on an OS .46 DF. I tried several different odd ball APC sizes and I ended up liking the 7.8 x 7 APC pylon prop. It has been several years since I had this combo. I don't remember what RPM it was turning (I think it was around 22K-23K on the ground), but it worked out well. I was running a Macs pipe, but I don't remember what the part # was. Hope this helps. 
01-01-2003, 02:17 PM
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OS46VXDF Pipe Question
Hi. I had some experience running one of these in a pylon ship when my f3d engine died. The MAC 8.5 unmuffled pipe worked the best. The sizes around 8.0 to 9.0 inches in diameter worked best. Pitch varied with conditions, but 7-8 was the range. The takeoff run was longer, but the engine unloaded to a little over 25k in the air according to the telemetry unit we were using and the speed was over 225. Happy speeding!
01-07-2003, 02:50 AM
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Hey Tom..
The VF is the FIRE version, a little different than the RIRE VXDF or VRDF, but I think it would pull a 8X10 just fine. I run a pair of 46VF's on the ol' Duellist..I am guessing the VF-P is a pumped version...I get about 17.4K on an APC 9X8 on full pipes, 11" glow plug to first peak of Macs 7.5CC unmuffled pipes. The 8X10 ought to get close to this, but surely ought to work.
I don't know about the mousse can muffler on these, I run pipes.
I don't know about the mousse can muffler on these, I run pipes.
