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the K&B .48 WILL turn an 11-7.5 faster than a majority of the 60's that are contemporary with the KwikFli design.... including my Webra Speed 60, K&B .61 and ST Blue Head .60....
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What does it turn it at ? I'll check my 6550 with a MAS 11-7.5. I'm curious ....are you talking about the MAS prop ?
Edit: I'm gonna guess 13.8K on the 6550.
FBD.
< Message edited by Flyboy Dave -- 4/25/2005 10:11:46 PM >
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There does seem to be a lack of American engines on the market. I personally prefer 4 strokes over 2 and so I'm even more limited.
In the past I have had very good luck with K&B engines; I had a 65 Sportster for some time and while it was no power house and weighed a bit more than desirable it was reliable. Same with my Sportster 20s but the king of all American made engines I have had are the 2 Fox 50s I had back in the early 90s. I used them on two different Sig Kougars and ended up crashing both of them badly damaging both engines badly (nose in, high speed, broken cases). I wouldn't have expected any engine to survive those crashes so I won't comment on them negatively for it. I ran one with a tuned pipe and a 10x7.5 three bladed prop. It's been a while and I don't recall the RPMs but I was pleased with the speed and response at the time.
I also have similar complaints to engine sizing...
Recently Magnum discontinued their 61 4 stroke which is an extremely light and well performing engine. I wish I had more, now all they have is their 70 which is almost the same size and weight as their 91 (which I have two of). The 61 though is very light and pulls a 13x6 prop very well on my Venus 40....when they disco'd it I was depressed and irritated.
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MAS doesn't make props..... those are double ended paint stirrers....
if you read my post you'd know that I'm viewing the KwikFki with a nostalgic eye..... that's why I spec'd a RevUp 11-7 1/2.... or maybe you were born after RevUp went out of business
FWIW....I have a friend with one of those, a blue and white one, new model. He has a Super Tiger .90 in it....we had a couple races last season. I blew his wings off with a 35 year old Super Kaos, and an OS .61 long stroke pattern motor. (slow revver)....with a 12-8 Zinger.
The reason he got blown off so bad was....that big fat KwikFli couldn't get out of it's own way....no matter what he had in it....
....so lemme see, your gonna put a .48 in the KwikFli....and do what ?
Man, I love a good story.
FBD.
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Phil Kraft's beauty in it's current incarnation....
SPECIFICATIONS NAME: Kwik- Fli. MANUFACTURER: Global Hobby Distributors WINGSPAN: 1422mm (56 inches) WING AREA: 37.1dm.sq (575 sq. inches) WING LOADING: 20oz. sq ft. AIRFOIL: Semi Symmetrical FUSELAGE: 1042mm (41 inches) WEIGHT: 2.39kg (5lb 2 oz) no fuel on board.
don't know where you got your mis-information !! These numbers agree quite closely with every current .46 type sport/pattern plane out there these days, and set the norm for .60 powered ships in it's day !!
PS.... the Kwik Fly was designed for TOC pattern flying, not pylon racing....
< Message edited by FenceMagnet -- 4/26/2005 12:38:59 PM >
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OK, FenceMagnet....I'm glad they made a smaller one. The wing on that big one must have been 3 inches thick....what a "log". You hang in there with that TOC pattern plane.
That K&B screaming .48 is a good engine I hear. --------------------------------------------------------------------------------------
Back to the K&B .61 business....I wish I had a Twister to run up against the old 6550 with, they are supposed to have "improved power and performance", but I've not heard of any real world specs on them. One would expect more RPM just because of the ABC type construction.
Here's my 6550 prop test. The 13.8K number I had in my head turned out to be the high rev number for the old .61. The test engine I would call "mid-life".... not new, but in good shape with an OS 7B carb on it, which is the same bore as the K&B carbs. I used some fresh 15% PowerMaster for the test.
11-6 MAS 13,800 11-7 MAS 12,900 11-7.5 MAS 12,200 12-6 APC 11,400 11-8 Graupner 10, 600 13-8 APC 9,200
See the 1500 RPM "dogged down" numbers for the 12-6 APC, as compared to the 11-7 MAS. The MAS will literally fly circles around the APC....yep. The 11-7.5 MAS trounces it even worse in real life.
The "Dog Prop of the Year Award" goes to the APC 13-8 at 9,200....I would expect the 13-6 APC to come in about 10K even....knocking almost 4,000 RPM off a perfectly good engine....so much for the "prop charts".
FBD.
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I have a K&B 6550 CF Lee engine and it does the 11-7 APC at 13,800. It's incredibly loud. Uses the old K&B square carb that resembles a HB carb except all silver.
I have a Direct Connection Kaos that I've set up for the K&B. The plane did nave a Fitzpatrick but I sold that engine to Hobbsy.
Enjoy,
Jim
< Message edited by w8ye -- 4/26/2005 2:52:32 PM >
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I have to wonder...... it's my considerable experience, having been at this for over 30 years, that the increased revs that you see with MAS props is because they flatten out.
< Message edited by Flyboy Dave -- 4/26/2005 6:46:47 PM >
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Yay, yet another APC vs MAS argument, yawn. I like both the epoxy spreaders (APC) and the paint stirrers (MAS). Which is better has, is, and probably will always be a subject for considerable debate. I'd really rather be running wooden props but since I fly off a grass field with some bumps, thick grass, vole holes, and lots of piles of deer "stuff", it's just not practical.
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quote:
ORIGINAL: piper_chuck
Yay, yet another APC vs MAS argument, yawn. I like both the epoxy spreaders (APC) and the paint stirrers (MAS). Which is better has, is, and probably will always be a subject for considerable debate. I'd really rather be running wooden props but since I fly off a grass field with some bumps, thick grass, vole holes, and lots of piles of deer "stuff", it's just not practical.
Must be a nightmare when the Stuff hits the fan !! (or the apc, or mas, or what ever.... )
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