MJD

My Feedback: (1)

On 15% oily fuel - anyone knowing this engine have a feel for what I should expect on an APC 6.3x4? Third run I momentarily leaned to 18,600-18,700 and there might be 100-200 left. I have no experience with .10's and .11's other than occasionally helping with an OS .10. Nor do I have a feel for that prop other than two short break-in runs on my .074.

Pond Skipper

If it unloads in the air at 19.7k to 20k should be good for around 75 mph on a clean air frame.

Pond Skipper

If you have a MA 6.5 x 3.5 you may like the extra thrust with around the same rpm but if you want speed
The APC Pylon prop 6.5 x 5 has a narrow cord thin at the tips to keep the rpm up and if unloaded at 19k you get 90 mph.

Here is the prop next to the 6.3 x 4

Mr Cox

The 6.5x5 is a great prop for .15 engines in a sleak airframe, but it is quite a high load for most modern .10 engines.

The airspeed will depend a lot on the airplane, cowling and landing gear are just as important as the wingprofile and wingspan. Put that prop on a .10 engine in J3 Cub and it will be nowhere near 90 mph...

Mr Cox

That sounds about right to me, I guess you have the stock muffler on?. I only have one of the CX.11 in ABC and one of the AAC (in glow version) myself and I haven't wrung them out properly, yet...

combatpigg

My Feedback: (3)

Mine is so old and tired that comparing rpm numbers is meaningless. I think the speediest APC prop would be the 5 x 5E. It's not an easy prop to run because it makes the engine very hard to start, plus you have the lack of thrust for hand launches.
MAS used to make a 6 x 4 with slim blades that really worked well. It was a great all around choice for a 26 inch delta..
I used a 5.7 x 3 for a "Pattern Bat" type model [remember them?] and the Enya .11 running with open exhaust, big venturi and a bladder. It was like watching a C/L Combat plane that had been cut loose. This combo was still pretty impressive with the muffler installed at the local club field. At first I was underwhelmed with the Enya .11 after reading the engine reviewer's hype. I was running it with a 7 x 3 and it becomes a "run of the mill" engine when you run it like that in a "Birdy .10" type model.
It was a bit expensive, so I had lofty expectations back then. Looking back on it, I got my money's worth out of it even though I had a few .15s that were competing for "playing time".

MJD

My Feedback: (1)

I figured out that the last time (and first time) I ran this engine must have been about 30 years ago. I must have read the same review. It certainly didn't blow me away when I bench ran it on a 7-3 prop - but what I may have done incorrectly back then, who knows. But my interest faded anyhow.

Noticed this morning that it handles really well. Brought it up to a fast but not peaked two cycle on the third run, and watched the rpm slowly but steadily climb about 500 rpm over maybe 30 seconds, like a butterfly drying its wings or something prophetic like that.

combatpigg

My Feedback: (3)

The review I read was by Chris Chianelli, who I think worked for MAN at the time. He also gave a Cox Queen Bee .074 a favorable review.
Today I pieced together a .049 reedie. All the crankcases in the junk box were gummed up, but the one I grabbed wasn't too difficult to loosen up.
After the first 30 seconds the engine started gaining rpm until it sounded "flyable"..but then it seemed to loose it's setting and it quit. I found that the crank case was about as worn out as any Cox case I've ever seen. It went from too tight to total trash in 2 minutes. I probably should have torn it completely down for a thorough cleaning instead of hoping it would do it on it's own.

Pond Skipper

I run after oil in mine and face them down till oil seeps past the prop plate then flip a few times and call it good for the next start up, keeps the wear down till new castor from the run starts pushing through...so far so good. A application that does waller out aluminum cases for me no mater what I do are with the RC boats the flywheel over time simply wears them out and in my case it has taken out two TD cases and 1 QB case over the years. Ideal would be to have the boats flywheel isolated on a bearing supported shaft with the engine having a flex coupler going to the flywheel. I have made a gear box once it worked very well and didn't take out the crank case.

aspeed

I was swearing at my Queen Bee for a while too. It was the plumbing problem witha swap meet plane that it came on. I guess the previous owner was swearing at it too. It ran fine on the test stand with no muffler, but didn't idle very well. I drilled an air bleed hole as a thread on RCU or somewhere mentioned, and now everything is AOK and ready to fly. I have good feelings about it now, even with my unloving feelings about reedies. Just have to wait for the field to open, and build a new shop, and move again, and set up my lathe and mills, and...... I found my .10's seem to like a 7-4" prop, but that was just for farting around, not really any speed trials. I think the combat props would be a good load, but the pitch may be a bit low. The MA 7-4's seem to run in the 17 to 18,000 range. I did have one running a 7-6 accidently, and it sheared the wing off my plane in a dive. It was a new plane from a swap meet, and the prop was just on. It did pick up a lot of speed going downhill.

MJD

My Feedback: (1)

Ah yes those highly informative reviews that get straight to the heart of the engine's genuine attributes and failings..

I think it was a Stu Richmond article - but at the time likely more than one person was ranting about the engine.

Been amusing myself this weekend bench running the MDS speed .15 as well. I didn't use an 8-4 like the guy on Youtube who complained it only did 13k. I'm down to 5x5.5 clipped Graupner speed and might need a hair less load for the bench.

Mr Cox

The MVVS .15 with a rossi pipe (very similar to the MDS .15 pipe) runs well with the previously mentioned APC 6.5x5 prop, gives +22000rpm on the ground. I haven't flown it yet though, need to add a pressure line from the pipe in order to have a rich enough high end.

I'm very happy with my Queen Bee now after converting it to diesel, using an RJL .09 head.
The carb needed modding though as there is no low end compensation from the factory. Both power and handling are not too far from the PAW .09 Mk I diesel actually. Kind of makes sense that engines with restricted breathing etc. runs well when converted to diesel.

https://www.youtube.com/watch?v=KLFfH1vQKSY

Pond Skipper

LP06040 6x4 Sport Gas Propeller APCQ0604 A.P.C.

http://www.ebay.com/itm/LP06040-6x4-...item3aa5e47240

This one has a thinner cord and airfoil - will allow the engine to run more rpm anticipate 19.4k with the CX .11

MJD

My Feedback: (1)

Yeah but it's a pusher..!

https://www.youtube.com/watch?v=FOd2wrE0vP8

Celebrating a gorgeous spring day with a noisy engine run. Last night I plugged the crankcase pressure tap, dropped a pressure tap in the pipe, and lo and behold, now I can needle it. Crankcase pressure doesn't work worth beans on this peaky setup.

Should be fun on a little SWR delta or something of that ilk.

Pond Skipper

NEW Flyzone 5x5 Propeller Hadron (2) FLZA6527
http://www.ebay.com/itm/331336372200

This is made for 4S lipo -speed prop for high watt motor.
Motor: 35-36-2200kV brushless
Electronic Speed Control: 40A


I bought two will test with my Norvel .074

Pond Skipper

Whoops here are the right ones for mounting up front.

NEW APC 6x4 Sport Gas Propeller (6) LP06040 NIB

http://www.ebay.com/itm/331321798750?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

aspeed

I have had no luck getting my MVVS .15 up to any speed. Wouldn't even do 14,000 with or without pipe. All the other stuff that size was around 17,000 up to 20,000, on the 7-5 MA prop. even the LA. Just the MVVS, TTiger and an old reedy Sportsman were dogs. (I forgive the Sportsman because it is older than me.) The Ucktam is a good runner at 18,500, that would be the rough looking combat one. The piped one was slower at around 15,000 with or without pipe. I think it will be fine with a smaller prop though because it has over 180 degrees of exh. timing. I played a bit with a Picco .12, and it looks like a good strong runner too 18,300 no pipe and 22,000 with it. I think the pipe is set for about that pipe and prop, because a smaller prop didn't pick up much with the pipe. I converted it from a car motor.

MJD

My Feedback: (1)

A 7-5 is a windmill to that motor/pipe combo I'd say (the Uctkam I mean). On the bench I ran a Graupner 6x5.5 cut to 5" and it staged fine with that. same as it did with the cf bench prop which has no real airfoil but seems to have maybe 3" pitch angle and a bit under 6" diameter.

Pond Skipper

My TD Special .15 swings a 7x4 at 20k wonder what it will do with a APC
I think on 25% nitro with a modern 6 x 5 should be around 19.5 perhaps 22k unloaded
The MK II should bust 20k static.
Here is the data sheet:

combatpigg

My Feedback: (3)

I was just looking through an old control line book written by Dick Mathis and he mentions something I had forgotten about. He offered a Rule of Thumb way to compare the Load Factor of props. You take twice the diameter, then add the pitch.
I recall reading this long ago, but never tested it for myself.

aspeed

I hope I can remember that rule of thumb. It sounds about right. I kind of figured one up and one down on diameter and pitch, but it didn't seem that accurate after a while, like going 6" to 8" diameter, so, maybe that is more correct. Back in the old high nitro days, a 6-7" was considered the prop to use for a .15 A speed plane. Naturally everyone thinned the tips a bit to get on the pipe. Now it is 6-5 with much less nitro. The Goodyear planes ran nice with the 7-5" because they were a draggy plane, and, well the motors would break with anything much less.

MJD

My Feedback: (1)

The standard FAI one blade props are in the range of a 6-6 cut in half with counterweight - i.e. 3-6, 2. 875-6, etc. and run at 35k plus.

Not sure where things are in AMA speed - similar with 10% nitro?

combatpigg

My Feedback: (3)

The Thrust HP Calculator that I used to use didn't consider pitch when calculating static thrust. Forum members at RCU questioned that, but I did my own tests with 1/2 A engines and didn't see any examples to disprove the Calculator's accuracy.
Measurable differences would show up much better with larger props, I'm sure.
MJD..........What do you have in mind for the Enya .11...? You could make an absolute Whirling Dervish with that thing if you put it on a stick built PBF.

MJD

My Feedback: (1)

I have a Baby Birdie half framed up from eons ago. The fuselage nose has a .10-.11 mount wedged in and fits the Enya nicely. I can just squeeze in a 3oz Hayes tank, I'd live with 2oz if I had to. Now.. to replace the wing airfoil..?

aspeed

Lately the A speed planes are just an F2A FAI plane with monoline on 65 ft. lines and 10% nitro. Pretty much the same guys running them too. There really isn't much happening in the speed circles.