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K&B .61 engine?
Anyone have any experience with the K&B .61 engine? Is it any good? What size prop does it like to spin? The weight listed on their website appears to be the same or lighter than most .46 size engines. Is this correct?
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RE: K&B .61 engine?
Yes, it's good. For a sleek pattern ship it spins an 11-7, or 12-5 or 12-6. Has a little more power than a .46 and weigh's only a little more. Most modern .60's are based on .90 cases so the older .60's are lighter. Check out the screw head that is mail order direct as it is only about $100 and more powerfull.
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RE: K&B .61 engine?
The K&B 61 that I have is more powerful than my other 61's when it has a 11-7 prop on it.
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RE: K&B .61 engine?
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PM:
I love them, I have quite a few. Best replacement for a 40-46 ever made. Airplane in the picture will take off vertically out of my hand with a MAS 12x6 three blade prop. Bill. |
RE: K&B .61 engine?
One of the best engines ever built! Clarence Lee customizes them with Perry Directional Porting and they can keep up with most of the modern .61's!
Phil |
RE: K&B .61 engine?
The K&B 61 was originally the Veco 61 and came out in 1965. It was designed by Clarence Lee. It is 40 year old technology but still a dependable and easy to use engine. Mecoa sells parts for it. It isn't as powerful as a modern schneurle ported 61 but for the price it is a great sport engine. I used several of them 30 years ago. Still have a couple somewhere around here.
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RE: K&B .61 engine?
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Bruce:
I still have one of the originals. Bill. |
RE: K&B .61 engine?
Gee, what a surprize.
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RE: K&B .61 engine?
ORIGINAL: Sport_Pilot ...Most modern .60's are based on .90 cases so the older .60's are lighter. It is exactly the opposite of what you wrote! Most modern .90/.91 engines are bored and stroked .60/.61 engines. The OS.91FX is built into the the .61FX crankcase and has the same size, weight and mounting dimensions. The clones from Sanye China (Magnum, ASP, SC....) are the same. The MVVS .91 (and .77) is the same size as the .61, except for being slightly taller. The Super Tigre, likewise.... If you want to know what a real vintage .91 weighs and looks like, the OS1.08FSR (and its clones, 750 grams, 26.5 oz.) has the same size crankcase as the OS.91FSR. The old Webra Speed .91, like Dave Hobbs has, is also a 'real' .91... The K&B .61 is a particularly light engine, at just 14.25 oz. (404 grams) bare. Other light .61 engines are the 1024/1030 from Webra, at 445 grams. The OS, MVVS and Super Tigre, just for comparative purposes, are 550-567 grams bare |
RE: K&B .61 engine?
How would the K&B .61 do in a 3D type airplane with total weight of 5 pounds? Would it spin 12", 13", and 14" props pretty well? How is the idle, midrange, and transition on this engine? I'm wanting to be able to hover and have tons of power to pull out of the hover. This engine would be replacing a Mecoa .46 with a mousse can spinning an APC 11x4. Thanks to all for your comments.
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RE: K&B .61 engine?
Hi!
As Dar said...all modern .90 engines are bored and stroked .60 engines. A 11x4 prop is way to small for a .46 engine at sea level and certainly is too small for a .60 engine. If those K&B engines were so good they would have been used 20 years ago by most F3A (Pattern flyers)...the thruth is; most top fliers prefered other engines like OS, Webra and Rossi because these were more powerful and reliable. I don't say the more modern gold headed K&B .60 with screw in-head isn't a good engine, it is. but there are very many engines today that are equal to it or better. Regards! Jan K Sweden |
RE: K&B .61 engine?
ORIGINAL: jaka Hi! As Dar said...all modern .90 engines are bored and stroked .60 engines. A 11x4 prop is way to small for a .46 engine at sea level and certainly is too small for a .60 engine. If those K&B engines were so good they would have been used 20 years ago by most F3A (Pattern flyers)...the thruth is; most top fliers prefered other engines like OS, Webra and Rossi because these were more powerful and reliable. I don't say the more modern gold headed K&B .60 with screw in-head isn't a good engine, it is. but there are very many engines today that are equal to it or better. Regards! Jan K Sweden ---------- The K&B .61 was the last of the crossflow .61 engines that was flown in pattern. After that, the much larger crankcase equipped Schneurle ported engines took over. That is why the modern .61 engines are so large. Schneurle porting forced them to widen the crankcase (that and larger bearings). The .91s were outgrowths of those changes. The K&B .61 was "hot stuff" in pattern (AMA not FAI) for a very short while in the early to mid seventies. But was soon surpassed by schneurle ported engines that responded better to the use of a tuned pipe. By the early eighties, the K&B .61 had been hopelessly outclassed by virtually any Schneurle ported engine. Would it be good for 3D? Truthfully, when it came time to make that decision, in that power range, I bought a Rossi .45 3D with special 3D muffler and two Saito .82a engines. I love the K&B .61, but I don't love grubbing for parts for them. |
RE: K&B .61 engine?
Ed,
Do you happen to know what type of porting K&B uses in the Twister 6150 and 6170 engines? The crankcase seems to closely resemble the 6550 that is discussed here, but the twist-on head precludes the use of baffled piston, unless the baffle slot is in a separate head button... This all strongly suggests it is Scneurle ported, but who knows. They all use the same bearings... same sizes and even the same weight... So, are they Schneurle ported, or not? |
RE: K&B .61 engine?
Parts are readily available from mecoa.
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RE: K&B .61 engine?
The K&B .61 was the last of the crossflow .61 engines that was flown in pattern. After that, the much larger crankcase equipped Schneurle ported engines took over. That is why the modern .61 engines are so large. Schneurle porting forced them to widen the crankcase (that and larger bearings). The .91s were outgrowths of those changes. Odd that the .91 sizes weigh little more? Their crankshafts are not as beefy relative to size. The modern crankcase size and bolt patterns are much larger than the earlier ones. Apparently they did this so that they would be able to use the same mounting on the .91 sizes. This was done on paper, before the engines came out. So even though the .91 engines were not out yet, the design for the .61's were basically a destroked and debored .91 design. With changes to the casting pattern to reduce the external cylinder size. There a few modern schneurle .61's which show that they need only to be slightly heavier than the old loop engines. The K&B, Webra, HP, and Fox come to mind. The Fox shares the same case pattern with the .74 so it is heavier than the others, but at 18 ounces it is still much lighter than the +20 ounce OS and OS clones. |
RE: K&B .61 engine?
ORIGINAL: DarZeelon Ed, Do you happen to know what type of porting K&B uses in the Twister 6150 and 6170 engines? The crankcase seems to closely resemble the 6550 that is discussed here, but the twist-on head precludes the use of baffled piston, unless the baffle slot is in a separate head button... This all strongly suggests it is Scneurle ported, but who knows. They all use the same bearings... same sizes and even the same weight... So, are they Schneurle ported, or not? -------------------- IIRC, they are indeed true schneurle ported engines and they are very snappy to boot. A few years ago there was a lot of hoopla when those engines were introduced. I've seen serious K&B iron at work in the past, so I know when they bear down on a project, it is going to scream. I never did get around to buying their Twister .61 or .48 engines. Sadly. I'm glad that RJL is still producing them. Maybe I'll spend a few bucks and play "catch up" with these two engines. |
RE: K&B .61 engine?
Light weight ball raced ABC engines can still be made when a company really tries to do it. Look at the Stalker range. The 40RE at 9.25 ounces, 40 and 46SE at 10.2 ounces, 51RE at 10.4 ounces, 55 and 61 in either SE or RE at 13.5 ounces. All of these weights include the muffler. The 61 is also available in a light weight :) version but I believe it's only about .5 ounces lighter.
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RE: K&B .61 engine?
So how would this new K&B .61 at www.mecoa.com compare to my Mecoa .46 with mousse can? I'm currently spinning an APC 11x4 a little over 14,000 rpm. Would it do well with a low pitch prop in the 12" or 13" range? Thanks for all the replys.
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RE: K&B .61 engine?
ORIGINAL: plasticmaster So how would this new K&B .61 at www.mecoa.com compare to my Mecoa .46 with mousse can? I'm currently spinning an APC 11x4 a little over 14,000 rpm. Would it do well with a low pitch prop in the 12" or 13" range? Thanks for all the replys. --------------- If you were to buy the latest Twister edition of the K&B .61, it would easily blow away the MECOA .46 on any size prop. |
RE: K&B .61 engine?
My K&B Twist spins a 14x6 prop and produces almost ten pounds of static thrust on my thrust bench. Is that enough thrust for a 5# plane?
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RE: K&B .61 engine?
ORIGINAL: Sport_Pilot The K&B .61 was the last of the crossflow .61 engines that was flown in pattern. After that, the much larger crankcase equipped Schneurle ported engines took over. That is why the modern .61 engines are so large. Schneurle porting forced them to widen the crankcase (that and larger bearings). The .91s were outgrowths of those changes. Odd that the .91 sizes weigh little more? Their crankshafts are not as beefy relative to size. The modern crankcase size and bolt patterns are much larger than the earlier ones. Apparently they did this so that they would be able to use the same mounting on the .91 sizes. This was done on paper, before the engines came out. So even though the .91 engines were not out yet, the design for the .61's were basically a destroked and debored .91 design. With changes to the casting pattern to reduce the external cylinder size. There a few modern schneurle .61's which show that they need only to be slightly heavier than the old loop engines. The K&B, Webra, HP, and Fox come to mind. The Fox shares the same case pattern with the .74 so it is heavier than the others, but at 18 ounces it is still much lighter than the +20 ounce OS and OS clones. ----------------- You are correct, I mispoke. The increase in size had more to do with an increase in crankshaft diameter and the resulting increase in ball bearing size. I realized it after I hit the sent button. The HP .61 popped into my mind. They had small crankcases. Thanks for the correction. |
RE: K&B .61 engine?
ORIGINAL: Sport_Pilot I suspect that was the OS which caused the modern .61's to gain weight, and I suspect it was a marketing ploy, that it is so much powerful that we had to put in larger bearings and crank. But since the OS FX the modern .61 are real pigs. I agree the OS.61FSR and other competitive .61 engines of that era, are much heavier than they actually need to be. Odd that the .91 sizes weigh little more? Their crankshafts are not as beefy relative to size. The modern crankcase size and bolt patterns are much larger than the earlier ones. Apparently they did this so that they would be able to use the same mounting on the .91 sizes. This was done on paper, before the engines came out. So even though the .91 engines were not out yet, the design for the .61's were basically a de-stroked and de-bored .91 design. With changes to the casting pattern to reduce the external cylinder size. They are HUGE in comparison to current .60-.91 engine. And no, those original Schneurle .60-.61 engines were not originally designed to be over-bored and over-stroked, to become .91 engines, or the original OS.91FSR would have been the same external size as the original OS.61FSR... There are a few modern schneurle .61's which show that they only need to be slightly heavier than the old loop engines. The K&B, Webra, HP, and Fox come to mind. The Fox shares the same case pattern with the .74, so it is heavier than the others, but at 18 ounces it is still much lighter than the +20 ounce OS and OS clones. |
RE: K&B .61 engine?
At a 2/1 thrust to weight ratio I would say you would have a real tiger by the tail! Should vertical OOS from your hand!
Phil [X(] |
RE: K&B .61 engine?
MikeSell,
What kind of rpm are you getting on the 14x6 prop? How is the transition from idle to full power? What about midrange? Which K&B .61 Twist do you have? Is it the one with the tuned muffler or the one that's available for $79.99 with trade in on the Mecoa website? |
RE: K&B .61 engine?
I have both the types of twist .61s. Two have the long pipes and one has the shorter fat pipe (6050 & 6060). Both out perform the OS.61FX by a sizable margin (I have a few of these too). I have not ever tached these engines with the 14x6 props but I did extensive thrust testing with a wide variety of props. Not all 14x6 props allowed the engine to peak. Some brands of props a 13x6 worked better.
The throttle response was very acceptable with the long pipe versions. I've had limited experience and testing with the fat muffler version (although that muffler does quite well on a .48). My purpose was weight lifting and thrust not speed was the major consideration. The plane lifted 52# gross weight and had a 15 foot wingspan. |
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