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JBA .56
Does anyone out there have a JBA .56?
I was just curious about how they run. |
RE: JBA .56
Hi Ed: I have two .46's and one .39 JBA engines. The .39 is the only one having gone through the break-in. It is mounted in an old Royal trainer right now waiting for test flying. While on the test stand, this .39 engine with a 9x5 prop and 10% castor oil fuel ran over 18,000 at the rich 2 cycle break point. The muffler does not keep the noise down very well though. My inspection of the engine before running found no bad discrepancies although I thought the c/s drilling for the carb induction a bit wrough. The .56 engine may perform as well as your SK .50.
Rich S. |
RE: JBA .56
Personally, I just love engines. I usually buy them to try them. I did tell the wife to get me another OS .55AX for Christmas.
I was just speculating on the JBA. If you calculate the displacement, it comes to just under .58. This is in a .40-.46 size case. Some time, if you punch the displacement out too much, you don't have enough room for the porting. I would hope the JBA would be like the old small case Super Tigre 60. The OS .55 is not in the same case as the .46AX. It looks slightly larger, but only weighs a little over 1 ounce more. It appears to be designed from scratch for the .55 displacement. Remember, nearly all of the .46s are bored out .40s with a larger bore and the same stroke/crankshaft. I remember some discussion several years back on the Just Engines .56. As I recall, they were trying for the largest displacement in a .46 size case. There were mixed reviews on it. Since it was the first of that size, it might be growing pains of the first production run. I'll probably get a JBA .56 down the road and hang it on a Stick to see how it runs. |
RE: JBA .56
J'EN .56 and JBA .56 ... same wine, different label? :D
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RE: JBA .56
Hey Ed, if I bought a JBA 0.56A and shipped it to you new in the box, would you write up a review (just a new post here in the glow forums) and then just send it back to me when you're done with it? I'm not looking for "War and Peace," maybe just some comments about break-in and flying along with some rpm readings of a few different popular 11" and 12" props.
I think a lot of engine enthusiasts would love to hear more about the JBA engines, and I'm sure I could find an airframe for it once you were done playing with the engine. Of course, there is this review out there: http://www.rcgroups.com/forums/showthread.php?t=603739 |
RE: JBA .56
Also I wonder what is the reason of that price difference from SK brand? What is the advantages of JBA s on them?
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RE: JBA .56
The new Just engines "56 is now a 57" same engine however it is now RINGED I have 2 JE 56s and no issues one had a sticky barb barrel a slight cleanup to the barrel slot fixed it
they are both the diesel version martin the very early versions SKs had samme problems no more under any of the labels |
RE: JBA .56
Ed,
That sounds good to me. I'm still going to get one myself. I'll PM you with my address and the details. I was stationed at the old Lincoln AFB back in the 1960s as a B-47 pilot. I flew control line then. It is probably not good flying weather this time of year. |
RE: JBA .56
Yep, that's why I thought I'd send one to you in Florida. We're well into building season here with snow on the ground and temperatures down into the teens and twenties most days.
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RE: JBA .56
One very experienced modeler striped the thread off as he was tightening the prop nut. The crankshaft was way soft. The engine never got a chance to run. I think it was the 40 size.
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RE: JBA .56
Wow! That's a pretty frightening antecdote, freakingfast. I can't imagine a prop shaft that was so soft the threading would just strip away like that; that must have been a sight to see.
The JBA .56A is ordered and on its way to Ed Moorman, so hopefully we'll all know more soon. |
RE: JBA .56
Prop shaft ends of crankshafts are rarely hardened.
Most likely the threads were undersized again from poor tooling practices and quality control? |
RE: JBA .56
ORIGINAL: w8ye Most likely the threads were undersized again from poor tooling practices and quality control? This is the biggest problem the Chinese face right now, ensuring that they ship products of a consistent quality. My SK50 (from the same factory as the JBA) came with a glow-plug hole that was so far out of spec I had to re-tap the threads myself. Obviously they weren't running any kind of regular check on the tooling or engines because the plug threads were so undersized that the tap they used must have been worn out ages ago. It strikes me that although the factory which makes Magnum, ASP, GMS and SuperTigre engines seem to have their QC sorted, the JBA/TS/SK factory has more than a little way to go in this regard. If you're lucky you'll get a nice engine -- if you're not, well you might as well flush your dollars down the drain. |
RE: JBA .56
1 Attachment(s)
Don't be so sure that the SK and GMS/Tower/Super Tiger engines are not made in the same factory.
Look at the mounting lugs of either of these engines. On the outer edges you will see the same numbering system. On the right lug is the year and month and on the left lug is the manufacturing sequence during that month. There is also a lot of similarity in the way the castings are designed around the bypass ports and the way the carburetor looks. The parts pictures are of a GMS 47 Tower 46 B&S 22 X 19.6mm GMS 47 22.4 X 19,6 SK 46 22 X 19.6 SK 50 (I mean 52) 23.64 X 19.6 JBA 52 23.64 X 19.6 JBA 56 (oh I mean 58) 23.64 X 21.6 JBA 56AR 23.35 X 21.6 |
RE: JBA .56
Hi W8ye,Though SK crankcase has a manufacturing no (ie:KA 01569) at left lug,no signs on right lug.Crankcase carb base casting is square
not rounded and prop driver hub has no separate cone,only has a matching flat surface sliding onto crank.So Im not sure,same factory products with Towers.But carbs seem same factory production most likely. |
RE: JBA .56
Turk,
Thanks Jim |
RE: JBA .56
Here's the quote from the Kangke web site:
Kangke USA is proud to add JBA engines to their line of quality products. Jiangnan Blue Arrow manufacturing is a trusted name in radio control engine production throughout Europe and Asia for many years. JBA designs and manufactures engines for airplanes, helicopters and cars and has been producing engines for other brands for many years. Only recently has JBA offered their line of engines bearing the JBA name. Their ISO9001 production facility is state-of-the-art with CNC machining, extensive quality control and an ongoing research and development that exceeds the industry standard in every aspect. Annually, JBA produces more than 200,000 engines for the radio control hobby industry. JBA products consistently exhibit stable performance, operate through extreme pressures and temperature ranges, have reduced weights, wide operating and adjustment parameters, smooth running, and high horsepower output. From design through production JBA has invested every possible resource to produce the highest quality engines, but at an affordable price. JBA engines come in two-stroke displacements ranging form .12 (2.0cc) to 1.20 (19.7cc) and horsepower output from .45 to 3.1. All JBA engines have a one year warranty. Kangke USA will also provide all replacement parts. Engines are shipped with mufflers and are pre-run at the factory to ensure easy starting and performance. Engines are equipped with a low-speed needle adjustment and a high-speed adjustment. JBA suggests 10-15% nitro fuel with glow plugs in the medium to hot range. Please keep in touch an JBA released their line of 4-stroke and gas engines in the near future. I would bet that a lot of the Chinese engine manufacturers use the same suppliers for many parts. This may account for the similarities. |
RE: JBA .56
Please keep in touch an JBA released their line of 4-stroke and gas engines in the near future. David |
RE: JBA .56
I asked Kangke for those Blue 4 strokes but they cant say any near future to provide.Why? I dont know.
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RE: JBA .56
You never know when something is going to creep up in the manufacturing process to cause delays. Thunder Tiger was delayed in introducing their new F-75s four stroke for over a year, and they've manufactured four stroke engines for many years.
Getting a whole new engine line ready to ship can't be an easy project. |
RE: JBA .56
Well, chalk one up for KangkeUSA; their shipping is fast. They got an engine from Deer Park, NY to Ed Mooreman down in Florida in four days right before Christmas.
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RE: JBA .56
Ditto BigMustafa,to otherside of the world,here, arrives mostly in 3 days after my order mail.Rarely 4. day delivery.I appreciate them.
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RE: JBA .56
I just ran the break-in on BigEd's JBA .56. Seems to run like an SK, which is really good.
1-flip started on every tank full. Never had to resort to a starter. After five 8-ounce tanks, I am turning an APC 11-6 at 12,800. This is the same as my OS .55AX. Same prop actually and same fuel, Omega 10% nitro, castor blend fuel. I set the low end on the 5th tank and it will hold a low idle (I didn't check the actual rpm, but it's low enough for me to taxi) then go straight to full power without a hesitation. I also ran for more than 30 seconds with the carb half open, then full power. No hesitation again. Next, I ran at 1/4 open for 30-40 secs and full power. It seems to have a very good carb. It does not shut down when you close the carb. Those of us who have SKs know that it takes about a gallon of fuel for the engine to really come in and at around that time, it'll shut down. This was mentioned in the SK thread and it worked for my engines. Maybe it takes that long for the castor oil crud to close up all the minor air leaks. I don't know. I do know the SKs keep gaining power for a gallon or so. I am going to assume the same for the JBA. I haven't flown it yet to see how it reacts in the air, but at first glance, it seems to be a good running power house for a low price, $80. I do plan to run several other sizes of 11" and 12" props and I have a Jett muffler to try. Since Ed can't use it right now up in Omaha due to snow and cold, I'm going to give it a good test. By the way, I also ordered my own JBA .56. |
RE: JBA .56
Ed,
That's a good report. |
RE: JBA .56
hi all. i use JBA 46, 56 and 61, 91, i saw all the engine is running well and good performance. i put JBA 56 AR on my spitfire with bolly propeller 11.5x7, the result the plane can fly very fast, and stable performance. and i fly it for 7 months already
i dont think that JBA is the same factory with SK or TS. but i think JEN and JBA engine is the same wine with different brand. |
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