LIMITED-B Prop Tests please ?

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lightning
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Post by lightning »

Jimbo, I fly Flat bats with Hat-trick E203 wing sets. Have not had a high breakeage rate with the 9x5 APC props I usually fly. This extra inch diameter seems to be causing me grief[:D][:D]

Oh and Bob (Boiler)- we did find my engine and the separated muffler. It sure was a good hit as about 50% of the fins are gone from my cylinder head plus some minor carb venturi reshaping[:(][:(]
Image.
PS - Also broke ANOTHER MA prop!

Keith J (member OGC)
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boiler
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Post by boiler »

Your muffler or mine? I actually borrowed one from Hat. It was sheered off in the collision with only the bolts left in my engine. Keep the tank, I may go to bladders when I finally destroy the last of my tanks. It seems like I'm always having problems with damage to tanks and fuel lines. Bladders let you know if they are bad before you launch and cost a ton less. They also assemble a ton faster![B)][B)]

Bob Loescher
Lima Ohio
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lightning
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Post by lightning »

Hey Bob, don't know whose muffler it is! My engine had no muffler either when we found it!!
It's a stock OS 25FX muffler, less baffle. Remains of one screw still in it, the other is gone with threads stripped out. It'll need retapping to 4-40 to use it again. No rush - I have a few!
If you (or Mike) need it I'll keep it in reserve for next time we meet! That or I'll donate it to Don Veres as he gave away all his stock OS's


Keith J (member OGC)
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lightning
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Post by lightning »

OK, we had a new flyer who borrowed one of my old Spads at the RCCD Limited B demo this weekend.
Stock OS25FX, baffle removed, MA 10x4 prop, Ritches brew 15% fuel, 74 degrees, humidity ???. 14,100 rpm.
Plane was as fast as any of them.[:D][:D][:D]
The new kid had a ball and can't wait to build some of his own.[8D][8D][8D]

Keith J (member OGC)
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boiler
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Post by boiler »

Your muffler. The one that Hat loaned me had the full baffle in it.[:D]

Bob Loescher
Lima Ohio
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Post by sgilkey »

Data from engine/prop tests at the RCCD Limited B demo. Pls note these are almost all from different tachs, so there is some measurement error here. THe only readings I normalized were from mine/Brians and Dr. Evils runs, which I took with my tach (TNC) to get direct comparisons. Listed readings will show % nitro (if available), muffler, prop, rpm

25FX engines
15% Ritch's, baffled muffler, 10x3A, 14k
15% Ritch's, no baffle, 10x4M, 14.1k
25% Omega, no baffle, 10x3A, 15,2
15% Powermaster, no baffle, 10x3A, 15.2
15% Powermaster, no baffler, 10x3A, 14.9
15% powermaster, no baffle, 10x4M, 14.7 (same engine as above at 14.9 on APC)
25% powermaster, no baffle, 10x3A, 15.3

NOrvel BM
15% Powermaster, stock muffler, 10x3A, 14.6

OS 28F
15% PM, stock muffler, 10x3A, 15.3
15% PM, sotck muffler, 10x4M, 15.0 (same engine as above)

Thanks to everyone for checking their motors, and thanks a bunch to Dr. Evil who recoreded everyone's readings for me!

We had so many planes in the air at once that it was impossible to get direct performance comparisons, however my lilmited observation is no engine or prop was out of the hunt. Speeds and performance looked pretty equivalent, nothing really stood out to me. I welcome other observations.



Scott Gilkey
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Post by RHorton »

Scott we need some flying with a 10x3 against the 9x4 and no tuned muffler. Just getting rid of the tuned muffler goes a long way in slowing open B down. If we can just get that done with open B I would see that as a big accomplishment. We are slowly adding new combat pilots up here, and all are flying stock mufflers.[:)]
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Post by Lou Melancon »

Ron,
I think you and Scott are talking about two different things. The first is Limited B, which is a different class than Open B. The folks who like Open B want it to remain Open. The idea that I think they are all working towards on this thread is to create a class slower than Open B with .25s.

Lou Melancon
Alpharetta, Georgia
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Post by BigCountry »

Ron,

While as Lou indicated we're speaking of two different ideas here Jimbo and I did exactly what you're referring to long before ever broaching the idea of creating a Limited B class and that is what drove us to the realization for us anyway that a 10" prop was necessary to knock some of that topend speed off the Open B planes. My testbed was the WASP and Jimbo's was of course his Raptors. While we didn't conduct extensive grueling tests we flew them enough to feel as though a larger diameter prop was necessary. I believe that if the results of the first three demos are evidence of a trend the 10" prop is one thing that will remain unchanged from the first rules draft. Now whether it's a MA or APC will remain to be seen but 10" none the less. I know that you feel strongly that a change to Open B is all that is necessary but that is not at the core of the Limited B idea. We have said that numerous times from the beginning that WE (Jimbo and I) do not want to see Open B changed. This idea was to provide a middle ground that folks would hopefully find doable and enjoyable...

Image
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Post by boiler »

I think I already confirmed Scott's observation, if I didn't then I will say all the planes were competitive. Of course you needed a good pilot to do well. Mine didn't.[;)]

Bob Loescher
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Post by C/F »

Hey, been reading thru here and guess what?? Still no Webra or Jett tests on any nitro let alone 30% heli my fuel of choice and used to break in all my engines.

Heres some points you are missing:

A jett 30 becomes a jett 25 for a $60 piston liner set. per dubb and myself conversation. Still own one Jett.30

Dubb will custom make any piston/liner timing needed even one to accomadate an expansion muffler as he built me a Jett.46 heli engine that I run on a muffler other than his for noise.

Webra 25 @ $85 "DO NOT" come with a muffler. However the Webra .32 does come with a muffler and the bolt pattern is the same since the .25 is the .32 case. I have a few .32 mufflers laying around.


I would gladly do the testing but 10X3 APC or MA are about as illusive as your Webra tests are. Send me some props ASAP...


Once "THE" muffler is found to be 15K and above (HELLO MACS) it will become a one muffler/engine class, and then the carb dialing on inspection joke continues just as long as you do not appear faster than the fastest plane regardless of the fact that his airframe is cleaned up with wing fillets and rounded LE coro tails, and all your guts are hanging out the side.............Theoratical speeds will be the norm two years from now bank on it.........
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Post by Jimbo »

I'm glad you thought of that. I guess we'll put an engine claim rule in and a price limit of $120. that would include the muffler. Why would anyone buy a HEAVY Jett to get 15.5K I have three and I wouldn't be stupid enough to put a $275. engine at risk to do the job of an $85. engine.

Limited-B
Try it,you'll like it !
Jimbo
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Post by Jimbo »

Now that you mention it Mike someone could also add and take away lead from their plane just for the tech inspection. Someone could also use high nitro for each round to get more R's and probably not get caught. Someone could work just the exaust port to get a better unload that would not show on a ground test. Hell lets just say F*** the whole thing and foget about it.

Limited-B
Try it,you'll like it !
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Post by Rabbit Leader »

Jimbo, keep at it, buddy. I think that the engine claim rule is a very good idea, as is an RPM check. BTW, just make all contestants peak their birds NOSE UP, with the needle, till she goes lean...back it off and tach. Doesn't take that long, gives you a TRUE reading of what the engine will turn, and you don't have to deal with pinching, etc.

"Furballs are for cats!"
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Post by Bad Dawg »

Don't give up Jimbo. There are some folks (myself included) who were born to debate and they will find points to refute and confound your ideas. Look at how quickly many of the the most active combat fliers have come on board to your idea, and how little dissagreement there is with your basic proposition. You are getting less forum oposition than SSC did, and you are getting more demo tests in less time than I expected. Keep at it. You are right.

NUNC AUT NUNQUAM
Mark V.
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