OS 46 VF versas OS 46 VR DF
07-12-2004, 07:17 PM
#1
OS 46 VF versas OS 46 VR DF
I have an OS 46 VF which has a front carburator and rear exhaust. I also have an OS 46 VR DF which has a rear carburator and rear exhaust. They both have the same case as it is marked with a V. The only difference I see is where the carburator is mounted. My question is; Given the same size prop will they perform the same? I am trying to decide which one would be the best on the plane called the Vertigo.
07-12-2004, 07:21 PM
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RE: OS 46 VF versas OS 46 VR DF
The VRDF is a fan engine... it has to be piped and turns 22,000+ rpm ideally...
I don't know what kind of plane that Vertigo is, but unless you intend to do 180 mph with it, go with the VF engine....
I don't know what kind of plane that Vertigo is, but unless you intend to do 180 mph with it, go with the VF engine....
07-12-2004, 07:25 PM
#3
RE: OS 46 VF versas OS 46 VR DF
ORIGINAL: Rudeboy
The VRDF is a fan engine... it has to be piped and turns 22,000+ rpm ideally...
I don't know what kind of plane that Vertigo is, but unless you intend to do 180 mph with it, go with the VF engine....
The VRDF is a fan engine... it has to be piped and turns 22,000+ rpm ideally...
I don't know what kind of plane that Vertigo is, but unless you intend to do 180 mph with it, go with the VF engine....
07-12-2004, 08:26 PM
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RE: OS 46 VF versas OS 46 VR DF
I see... I think I know what Vertigo you are talking about.
In that case the VRDF is the way to go.
It will not realise it's full potential without a pipe, but you definitely need the power (rpms) from this engine to get this plane going... since you are restricted in prop size. I believe the original had a three bladed prop and a df engine for the same reasons.
Using a pipe on this design would obviously be a PITA.
Where did you get the plans for this thing...? I have been interested in it since I first read about it some 15 years ago...
In that case the VRDF is the way to go.
It will not realise it's full potential without a pipe, but you definitely need the power (rpms) from this engine to get this plane going... since you are restricted in prop size. I believe the original had a three bladed prop and a df engine for the same reasons.
Using a pipe on this design would obviously be a PITA.
Where did you get the plans for this thing...? I have been interested in it since I first read about it some 15 years ago...
07-12-2004, 10:11 PM
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RE: OS 46 VF versas OS 46 VR DF
Yeah, but I bet due to the timing, a VF without pipe would turn better than a VRDF without pipe. Without a pipe, the sleeve of the VRDF is gonna spit a lot of fuel out that the VF would burn, just my thinking on the deal. I personally would do everything possible to run a pipe on either engine, just know that the VF really has very conservative exhaust duration...not really even pipe-timed. I'd still go with the VF.
07-13-2004, 12:19 AM
#6
RE: OS 46 VF versas OS 46 VR DF
Seeing as how ifly has got both types it'd be interesting to know if there's any difference in the port timings between the two. As Chuck said, the VF has quite conservative exhaust timing (my 40VF has 140 degrees total) but I've always been under the impression they were designed as a DF engine as well. Both types came out at about the same time so I'd have guessed they both used the same liner.
07-13-2004, 04:57 AM
#8
RE: OS 46 VF versas OS 46 VR DF
ORIGINAL: downunder
Seeing as how ifly has got both types it'd be interesting to know if there's any difference in the port timings between the two. As Chuck said, the VF has quite conservative exhaust timing (my 40VF has 140 degrees total) but I've always been under the impression they were designed as a DF engine as well. Both types came out at about the same time so I'd have guessed they both used the same liner.
Seeing as how ifly has got both types it'd be interesting to know if there's any difference in the port timings between the two. As Chuck said, the VF has quite conservative exhaust timing (my 40VF has 140 degrees total) but I've always been under the impression they were designed as a DF engine as well. Both types came out at about the same time so I'd have guessed they both used the same liner.
Thanks to all for their comments.
07-13-2004, 05:24 AM
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RE: OS 46 VF versas OS 46 VR DF
A degree wheel you'll get here:
Thread: Hop up your two stroke engine.
(Post No. 6)
http://www.rcuniverse.com/forum/m_18...tm.htm#1873945
Thread: Hop up your two stroke engine.
(Post No. 6)
http://www.rcuniverse.com/forum/m_18...tm.htm#1873945
07-13-2004, 10:58 AM
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RE: OS 46 VF versas OS 46 VR DF
I have both, a degree wheel, and can scrounge up some time.
I've run the VRDF on a Diamond Dust, it seems like it had conservative timing for a DF engine, but still quite a bit longer duration than the VF. I'm thinking maybe 172 on the exhaust duration.
And Razor, I have a 46 VXDF also
I've run the VRDF on a Diamond Dust, it seems like it had conservative timing for a DF engine, but still quite a bit longer duration than the VF. I'm thinking maybe 172 on the exhaust duration.
And Razor, I have a 46 VXDF also
07-14-2004, 08:40 PM
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RE: OS 46 VF versas OS 46 VR DF
OK
OS 46 VF is 148 degrees exhaust duration.
OS 46 VRDF is 168 degrees exhaust duration.
And for Razor:
OS 46 VXDF is 175 degrees exhaust duration.
Exhaust duration is all I checked, all I was talking about was spitting excess fuel out due to too much exhaust duration without a pipe.
Some pics. All, VRDF, VF, VXDF.
OS 46 VF is 148 degrees exhaust duration.
OS 46 VRDF is 168 degrees exhaust duration.
And for Razor:
OS 46 VXDF is 175 degrees exhaust duration.
Exhaust duration is all I checked, all I was talking about was spitting excess fuel out due to too much exhaust duration without a pipe.
Some pics. All, VRDF, VF, VXDF.
07-14-2004, 09:15 PM
#14
RE: OS 46 VF versas OS 46 VR DF
ORIGINAL: ChuckAuger
OK
OS 46 VF is 148 degrees exhaust duration.
OS 46 VRDF is 168 degrees exhaust duration.
And for Razor:
OS 46 VXDF is 175 degrees exhaust duration.
Exhaust duration is all I checked, all I was talking about was spitting excess fuel out due to too much exhaust duration without a pipe.
Some pics. All, VRDF, VF, VXDF.
OK
OS 46 VF is 148 degrees exhaust duration.
OS 46 VRDF is 168 degrees exhaust duration.
And for Razor:
OS 46 VXDF is 175 degrees exhaust duration.
Exhaust duration is all I checked, all I was talking about was spitting excess fuel out due to too much exhaust duration without a pipe.
Some pics. All, VRDF, VF, VXDF.
With the measurements you have taken and your comment about loosing fuel without a tuned pipe for the VRDF, it appears to me that in my application the VF would be the best fit. I do see now how the longer duration would allow the pipe to stuff the chamber.
Very interesting indeed. Thanks for your effort.
07-14-2004, 09:27 PM
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RE: OS 46 VF versas OS 46 VR DF
Yeah, but the VF won't get the plane off the ground...
Don't know if you've seen it, but there's a construction article [link=http://www.rcgroups.com/links/index.php?id=4453]HERE[/link]
You can see in that article what the guy used for exhaust... very simple... less noise... and tank pressure (very important).
There's also a video here [link=http://www.rcgroups.com/articles/rcpowermag/2004/may/vertigo/Vertigo%20at%20Lake%20Wales%202002.wmv]VERTIGO VIDEO[/link]
You can clearly tell from the video that the power from the newer and more powerful VXDF engine is just barely enough to get the plane to take off vertically... so the slow revving VF isn't going to cut the mustard, you can count on that!
Don't know if you've seen it, but there's a construction article [link=http://www.rcgroups.com/links/index.php?id=4453]HERE[/link]
You can see in that article what the guy used for exhaust... very simple... less noise... and tank pressure (very important).
There's also a video here [link=http://www.rcgroups.com/articles/rcpowermag/2004/may/vertigo/Vertigo%20at%20Lake%20Wales%202002.wmv]VERTIGO VIDEO[/link]
You can clearly tell from the video that the power from the newer and more powerful VXDF engine is just barely enough to get the plane to take off vertically... so the slow revving VF isn't going to cut the mustard, you can count on that!
07-14-2004, 09:34 PM
#16
RE: OS 46 VF versas OS 46 VR DF
ORIGINAL: Rudeboy
Yeah, but the VF won't get the plane off the ground...
Don't know if you've seen it, but there's a construction article [link=http://www.rcgroups.com/links/index.php?id=4453]HERE[/link]
You can see in that article what the guy used for exhaust... very simple... less noise... and tank pressure (very important).
There's also a video here [link=http://www.rcgroups.com/articles/rcpowermag/2004/may/vertigo/Vertigo%20at%20Lake%20Wales%202002.wmv]VERTIGO VIDEO[/link]
You can clearly tell from the video that the power from the newer and more powerful VXDF engine is just barely enough to get the plane to take off vertically... so the slow revving VF isn't going to cut the mustard, you can count on that!
Yeah, but the VF won't get the plane off the ground...
Don't know if you've seen it, but there's a construction article [link=http://www.rcgroups.com/links/index.php?id=4453]HERE[/link]
You can see in that article what the guy used for exhaust... very simple... less noise... and tank pressure (very important).
There's also a video here [link=http://www.rcgroups.com/articles/rcpowermag/2004/may/vertigo/Vertigo%20at%20Lake%20Wales%202002.wmv]VERTIGO VIDEO[/link]
You can clearly tell from the video that the power from the newer and more powerful VXDF engine is just barely enough to get the plane to take off vertically... so the slow revving VF isn't going to cut the mustard, you can count on that!
Thanks for the links, especially the video one.
07-14-2004, 09:53 PM
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RE: OS 46 VF versas OS 46 VR DF
Well if the VF won't get it off the ground, I sure wouldn't waste my time or money on the VRDF or VXDF. Seems like a larger engine is called for (and realize that the VXDF is a very heavy engine for a .46). I haven't seen the plane or the video, but I'd be re-evaluating my engine choices right about now.
03-03-2005, 12:56 AM
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RE: OS 46 VF versas OS 46 VR DF
hi could u tell me what a os 40 vf engine is used for originally?
the proper rpm range?
if its good for the DD?
the proper proppellerto get the most speed?
nitro to run them at
and the perfect pipe?
tanx
simcoeflyer
the proper rpm range?
if its good for the DD?
the proper proppellerto get the most speed?
nitro to run them at
and the perfect pipe?
tanx
simcoeflyer
03-18-2005, 10:50 AM
#21
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RE: OS 46 VF versas OS 46 VR DF
The O.S. Max "V" series of engines were essentially similar the "FSR" series, except that they had rear exhausts. That was to make it easy to put a tuned pipe in a fuselage tunnel. The "VF" was a front-intake engine, and the "VR" was a rear intake engine. The "FSR" engines and "VF/VR" engines had the same carburetors. The "VF/VR" engines were primarily intended for F3A Pattern flying.
The ducted-fan engines were ported for the high RPM required in ducted-fan use, and also required a tuned pipe to develop that RPM.
The ducted-fan engines were ported for the high RPM required in ducted-fan use, and also required a tuned pipe to develop that RPM.
