K & B Engines

[Mike Griffin]

Are the K & B engines good for sport flying?  I have never used one so I don't know how the quality is.

Thank you
Mike

[Garf]

Which series are you refering to. I know of several.

[M Spencer]

Never Heard of Wisniewski ?





sounds dangerous. http://www.airplanesandrockets.com/motors/how-bill-wisniewski-reworks-his-engines-jun-1957-am.htm

bout 2 horse @ 22.000 .


Cor



Progenetor of Nelson 15 , good goodyear & .15 pylon , but the Rossis had arreived .



theres 28 K&B engine tests http://sceptreflight.net/Model%20Engine%20Tests/Index.html here. That should keep you going .

[Randy Cuberly]

Well the question was about Sport Flying not Rat Racing or Speed.  K&B dominated Rat racing through the 1980's and into the 90's.  A couple of guys from California were flying a carbon fast rat at over a 165 mph with one of the modified rear exhaust 6.5's (.40).

However as for sport flying the last series of engines they made were very powerful and ran very well but had serious longevity problems.  They used an aluminum piston running in an aluminum sleeve (no chrome etc just bare aluminum) and the results were exactly what you would expect.  Well designed but fatally flawed!  I still have one that Bill Wisnewski sent me to test.  He didn't like the results of my testing and I think I lost him as a friend.  It still runs pretty good but coats the wing of the airplane with shiny aluminum flakes after every flight!
No I haven't flown it since the early 90's but keep it as a "keepsake" for the time when Bill was my friend!

The older K&B "Racing Engines"  like the 5.8 (.36) (I have three that I used for carrier in the past), and two 6.5"s (.40) (that I used for fast rat).  They were fast (for their time), and reliable but parts soon became a problem when K&B switched to their  "Sporter Series",  The one talked about above.

The 4011 series (1970's and 1980's) were the Quickie Rat engine of choice.  They were reliable and fast for the rules of quickie rat at the time it was popular.

The last series that I'm familiar with before the Sporter series was the 4050.  I still have one of those that I used in a Jamison for OT Stunt, and it runs very well but not particularly powerful.  It is reliable and easy starting and easy handling.  It is in my opinion a good sport engine albeit a little on the heavy side when compared to the OS FP's.   Too bad they weren't more popular at the time they were made.  K&B might have done better to develop them instead of what they chose to do.

In the 1950's the K&B Green head series engines were popular for Rat Racing and Combat for a while.  I owned and used many of them.  A few Green heads were modified and used successfully for stunt in the 60's and 70's.

This is not meant to be a treatise on K&B engines just a review of the ones that I'm familiar with and used in the past.  There were many other engines designed and used by Bill W. and others to set world records in both CL and FF but not available to the ordinary guy!

If anyone has a 4050 series and wants to use it as a sport engine don't hesitate to do so.  In my opinion it's one of the best all around sport stunt engines K&B made!

The sporter series 45 could have been the answer to CL stunt if it had simply been made as an AAC (my humble opinion and what I told Bill W.).  The one I had to test flew a 59 oz Magnum with great authority until it just wore out the sleeve at about 100 flights.  Several other Expert fliers flew it at the time (early 90's) and were impressed with the power and stunt run!  I guess it just wasn't meant to be!
No it wasn't fuel problems.  It was run on 15% nitro and 24% Castor.

Randy Cuberly

[George]

In the .15 size, after the Green Head came the Series 61 which has a rear intake and BB's. Next was the Series .64 which was an improved Series 61. Next Bill Wisniewski developed his "Wart" .15 which had Schnuerle porting and was soon released by K&B. That bumped his speeds above other competitors. When other manufacturers started equaling his performance he developed the tuned pipe. That once again raised the bar for speed competition. I think development on the K&B .15 size stopped when K&B bought the rights to the Cox Conquest .15 and dropped their own .15. I believe any further development was on the Conquest.

Of course other sizes were also developed by Wisniewski during that time but I do not have any of them.

I have no idea of how many other engines Bill Wisniewski developed after I dropped out of modeling for a few years. Perhaps someone can fill-in the gaps.

This may not be completely correct but it is the way I remember reading it in the model magazines of the day. I have never flown speed.

If the question is about K&B's current line, I would suggest checking the K&B section of the MECOA site and ask about a specific engine you are interested in. If it is a previous version, SOMEONE will have flown it.

George

[Akihiro Danjo]

As for Mecoa's K&B 18, it is OK for sport flight.
I replaced the carb with OS 6.5mm venturi and Enya 4mm NVA.
The conrod is cheap bronze and the PC fit was not very tight. Has less power than OS FP15, but they are OK for sport use. Easy to start and easy to set.
I have used one with a profile model and a Bolly clubman 8.5 x 4 prop.
Aki