FORA / CYCLON .15 powered speed plane
03-17-2014, 05:36 AM
#201
That combustion chamber, while small, is misleading because of the flush piston to the top of the liner, which is unusual to see. Another 1/4" dia. should be subtracted from the OD to look like a more conventional motor. It is meant for 10% fuel, so maybe a shim would be a good thing for higher nitro. Those short needles are well designed for combat, the whole assembly weighs nothing, and the needles don't get bent in the many crashes. Kind of hard with a cowl. If you are using the muffler, the older ones were 8mm outlet, while the newer rules require 6mm max. to slow them down a bit.
03-17-2014, 07:51 AM
#203
I looked into the exhaust port and it looks like the engine designer has set the top of the casting in the case at 180. I've seen this quite often..the Webra .50 for one example.
A pipe is pretty cheap..about $30-40. The header needs a small bend [to correct the angle of the tilted exhaust stack] and a piece of tubing that is a slip fit over the gasket on the exhaust outlet stub. Yes, this would come later because it diminishes the "EZ FUN" that I talk about in the first post. If there is an explosive jump in power it will also expose any short comings with the plane. I have a mental image of doing 150 mph with open exhaust and 170-180 with a pipe.
A pipe is pretty cheap..about $30-40. The header needs a small bend [to correct the angle of the tilted exhaust stack] and a piece of tubing that is a slip fit over the gasket on the exhaust outlet stub. Yes, this would come later because it diminishes the "EZ FUN" that I talk about in the first post. If there is an explosive jump in power it will also expose any short comings with the plane. I have a mental image of doing 150 mph with open exhaust and 170-180 with a pipe.
03-17-2014, 09:53 AM
#206
The old A speed planes used a 6"-7" P prop before pipes came along, and 80% nitro was allowed. 30,000 rpm works out to 210 mph. Your results will vary fer sure. The newer motors like to rev more, there are no draggy lines...
03-17-2014, 10:36 AM
#207
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I have read where these motors have been able to turn in the area of 33Krpm.
I told CP 250 would be not out of the question if hes' got enough oomph. That planes looks clean enough that a 5.5X6.25 prop may take it into that region.
03-17-2014, 10:45 AM
#208
You might think so, but the 1/2A version of this plane with a Cyclon .061 turning a 4.2x4 APC in the 36-39,000 range only did about 125 mph.
The identical engine / fuel / prop in a V-Tailed "Quickie 125" type plane did almost 150 mph.
Granted, the 1/2A BATOUTTAHELL might have had workmanship type flaws or wing loading beyond optimal, it has "artistic" features to give it a "bat style look" that might not be helping.
This .15 size version might have poorly executed [draggy] wing tips, airfoil flaws [I'm sure that a wing this size shaped by eye will have issues]], but I'm pretty sure that the finished wing loading will be pretty decent.
I'm pretty sure the best bang for the buck will be to build another V-Tailed Quickie 250 type plane with a cowl. A conventional, boring design layout that is hard to beat.
The identical engine / fuel / prop in a V-Tailed "Quickie 125" type plane did almost 150 mph.
Granted, the 1/2A BATOUTTAHELL might have had workmanship type flaws or wing loading beyond optimal, it has "artistic" features to give it a "bat style look" that might not be helping.
This .15 size version might have poorly executed [draggy] wing tips, airfoil flaws [I'm sure that a wing this size shaped by eye will have issues]], but I'm pretty sure that the finished wing loading will be pretty decent.
I'm pretty sure the best bang for the buck will be to build another V-Tailed Quickie 250 type plane with a cowl. A conventional, boring design layout that is hard to beat.
03-17-2014, 11:35 AM
#210
Those are probably piped .15s. They run a lot harder than this regular timed version will.
I've heard them running and it sounds like 40,000 +.
Unless replacement parts are cheap and easy to get, this level of performance is beyond what I want to spend for now.
I've heard them running and it sounds like 40,000 +.
Unless replacement parts are cheap and easy to get, this level of performance is beyond what I want to spend for now.
03-17-2014, 12:08 PM
#211
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I hear you, there was also a lot of talk about blown rods and shattered pistons on that forum as well.
Apparently aftermarket parts are not uncommon for these engines.
For what's it worth no mention of pipes that I saw, lots of talk about intake fingers (?) and timing changes though.
Apparently aftermarket parts are not uncommon for these engines.
For what's it worth no mention of pipes that I saw, lots of talk about intake fingers (?) and timing changes though.
03-17-2014, 12:52 PM
#212
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According to the conversational rundown I got on the phone from an F2A competitor that past Friday - the high end F2A engines like the Profi TOP can get over 40k once unloaded and staged on the pipe, mebbe up to 42-43k. Typical props in the one blade 3" x 6" range depending on weather and which engine (Profi, Irvine, etc). The second string engines, great for regional comp etc. that can get your ukies up to the 290-300kph or a bit over mark run in the 35-37k range on similar props (Profi Jr for example).
There is a "small" difference in cost for the two levels of engine..
.. as I also found out during that conversation.
I did see somewhere that the F2D engines run in the 32-33k mark in the air. Typical props 6 - 6.3 x 3.5 - 4.0 or thereabouts.
There is a "small" difference in cost for the two levels of engine..
.. as I also found out during that conversation.I did see somewhere that the F2D engines run in the 32-33k mark in the air. Typical props 6 - 6.3 x 3.5 - 4.0 or thereabouts.
03-17-2014, 01:46 PM
#214
I measured my lowly AP .15 (which is really only a .135) at almost 25,000 on one of those F2D props. I measured it on my home made pitch guage at 5" pitch and 6.2" dia. The blades are so thin that they don't grab much air. I think a real motor will go 110 mph in a combat plane. 100 for sure, and they are not very clean. They sure turn tight without slowing down. Kind of gets the heart rate up for a old guy like me.
03-17-2014, 02:51 PM
#216
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The other interesting thing is that he said the engine life on the F2A models is very good, his best flight ever was around #60 on the engine, and they go much longer. So I don't think the engines are flying apart all over the place. Not sure the rpm is the core issue, more like botched mixtures, overpropping, the sort of things that cook other engines too. Although getting things right is a lot harder I am sure!
RC = IMC = fix it in the air.
RC = IMC = fix it in the air.
03-17-2014, 03:13 PM
#217
Yes, the IMC will save a lot of money. I do not see room for one here.
Yes, a high timed engine on tuned pipe is like a roided out weight lifter. It WILL try to turn so much prop that it inflicts severe injury to itself.
You will see this same thing happen with unsupercharged aero-engines to some degree, but you won't see the same catastrophic results after a failure to get either the load, the compression, or the fuel recipe set right.
The fuel mixture changing during flight can be a result of failing to get the aforementioned factors correct.
It takes patience to work from the safe side of all these factors towards what is optimal. It is also a juggling match while riding a unicycle.
This is just some of the fun that running a 3 phase ON / OFF switch will never be able to replace.
Yes, a high timed engine on tuned pipe is like a roided out weight lifter. It WILL try to turn so much prop that it inflicts severe injury to itself.
You will see this same thing happen with unsupercharged aero-engines to some degree, but you won't see the same catastrophic results after a failure to get either the load, the compression, or the fuel recipe set right.
The fuel mixture changing during flight can be a result of failing to get the aforementioned factors correct.
It takes patience to work from the safe side of all these factors towards what is optimal. It is also a juggling match while riding a unicycle.
This is just some of the fun that running a 3 phase ON / OFF switch will never be able to replace.
03-17-2014, 03:45 PM
#218
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RMV is a nice option if space and weight is not an issue, by the looks of it CP didn't allow much room for baggage on this one.
CP I did read they like spin them up with something driving them when they are new while feeding them lubricant to mate the piston and sleeve, does that make any sense?
CP I did read they like spin them up with something driving them when they are new while feeding them lubricant to mate the piston and sleeve, does that make any sense?
03-17-2014, 04:04 PM
#219
Yes. I'll use a 5x4 prop and 30% oil 5% nitro to get it to run full tanks out with no residue in the exhaust, a steady needle setting from start to finish and no signs of over heating. I won't bother taching it, until the engine is able to run well with a "target prop" for the actual speed trials.
I've got 6 different props on order with Eliminator that I think might work. The shortest is 5.5 inches and the pitches range from 5 to 6.
4 prop choices come from his 5 inch diameter family, and 2 come from his 6 inch family. They are almost pure carbon, so they are very easy to modify.
I've got 6 different props on order with Eliminator that I think might work. The shortest is 5.5 inches and the pitches range from 5 to 6.
4 prop choices come from his 5 inch diameter family, and 2 come from his 6 inch family. They are almost pure carbon, so they are very easy to modify.
03-19-2014, 06:36 PM
#220
Well...I made my HF lathe do some work [a spinner nut] today, along with my HF drill index and HF tap & die set...oh yah, also some HF thread cutting oil and took measurements with my HF dial calipers.
I had a #6-32 pressure fitting laying around and installed it in the thickest part of the case. A sideways ditch needed to be cut from where the hole enters the case to get out from under the backplate. I checked for free and easy air flow and it seems like this will work.
I had a #6-32 pressure fitting laying around and installed it in the thickest part of the case. A sideways ditch needed to be cut from where the hole enters the case to get out from under the backplate. I checked for free and easy air flow and it seems like this will work.
03-20-2014, 07:00 PM
#222
It took a lot of time to tend to the micro plumbing..but it was fun. Just about everything needed to be tampered with in some way to make it doable. The goal was to allow refueling from the ehaust tunnel. Both feed and pressure lines need to be broke open to refuel. I'll need to use hemostats to work with the little lines, but it looks like it will work.
Later tonight I'll mix up a batch of paint and shoot the center section. The wings were covered with Towerkote, but the plane still needs graphics.
I decided that there is room for a 4 cell AAA nimh pack up next to the tank..so that's the plan for that.
To fit a pipe to this thing, the engine would need to come forward, new engine mount made, new cowl made and I might be able to make the header since all it needs is a length of tubing with a short hunk of tubing that is a slip fit over the header pipe to act as the coupling at the exhaust outlet on the engine.
The extra side area would definitely call for more fin. I already have my doubts about the fin with what we got right now.
Later tonight I'll mix up a batch of paint and shoot the center section. The wings were covered with Towerkote, but the plane still needs graphics.
I decided that there is room for a 4 cell AAA nimh pack up next to the tank..so that's the plan for that.
To fit a pipe to this thing, the engine would need to come forward, new engine mount made, new cowl made and I might be able to make the header since all it needs is a length of tubing with a short hunk of tubing that is a slip fit over the header pipe to act as the coupling at the exhaust outlet on the engine.
The extra side area would definitely call for more fin. I already have my doubts about the fin with what we got right now.
03-20-2014, 08:39 PM
#224
Looking at photo #1 from above, looks like CP's left index finger got caught up in something very sharp, hopefully not "tweaking" the needle valve with his ball driver. Nice project though, I have been lurking behind the façade here. 
