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Author Topic: K&B .40 by Clarence Lee?  (Read 472 times)

Offline frank mccune

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K&B .40 by Clarence Lee?
« on: July 06, 2022, 10:26:14 AM »
        Hello All:

         While flying the other day, my flying mate produced an older K&B .40 engine that ran perfectly.  First flip start and perfect 4-2-4 run.  I asked about the engine and he told me that Clarence Lee had worked on it. Total cost was $35.00 so this must have been decades ago.

          Has anybody ever else seen or used this engine as reworked by CL?

          Be well,

           Frank

Offline Dave Hull

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Re: K&B .40 by Clarence Lee?
« Reply #1 on: July 07, 2022, 01:31:46 AM »
Frank,

I have not seen a Lee-reworked K&B .40, but not too many years ago, Brodak carried a control line version of the old 4011 engine built by MECOA. The one I saw ran fine.

Dave

Offline Steve Helmick

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Re: K&B .40 by Clarence Lee?
« Reply #2 on: August 04, 2022, 06:13:35 PM »
Not too many years ago Clarence Lee advertised in Model Aviation classifieds, selling reworked K&B/Veco .61's, as I recall. I would expect that he would select parts to give better fits, adjust the ring gap better than factory, and not a lot else. I don't recall anything about CL stunt in the ads, so I'm thinking he was more into supplying better than average engines to the Vintage R/C Pattern guys. Would imagine he's in his 80's or 90's and maybe stopped that.  :o Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Steve Helmick

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Re: K&B .40 by Clarence Lee?
« Reply #3 on: August 04, 2022, 06:32:43 PM »
Frank,

I have not seen a Lee-reworked K&B .40, but not too many years ago, Brodak carried a control line version of the old 4011 engine built by MECOA. The one I saw ran fine.

Dave

That was the #4055, with the late (sturdy) front end. They are really heavy. The best thing I found out about the one I flew awhile in a Humongus was that a .46LA bolted right into the same holes and let me take some tailweight off as well as significantly more power. Believe there was also a #4050, maybe with throttle? They were made just before K&B went Tango Utah, and the story I read was that Brodak's order for them delayed K&B's closing by a few months.

I'm not real sure what a #4011 was, but think it was the earlier type front end with the propdriver held in place with a setscrew and (later ones) also a splitpin?

The #4055 was ABC, had 3 intake ports, but the crankcase only had one big bypass. I think it was just cheap to produce with existing case castings. Can't really see that being optimal...can you? They did run ok if you could cope with the approximately 10.5 oz weight without muffler.  :'( Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Dave Hull

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Re: K&B .40 by Clarence Lee?
« Reply #4 on: August 05, 2022, 02:07:39 AM »
The older .40 with the small bearing front end, the aluminum hub that was set-screwed and pinned on was the 8011 in its R/C form. They work ok as long as you never let the sacrificial prop shaft come in contact with the roll pin. The bigger front end engine was the 4011 which got rid of the sacrificial shaft and used a one-piece crank. No more loose drive hub from pin failure or pounding set screws....


Offline Motorman

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Re: K&B .40 by Clarence Lee?
« Reply #5 on: August 05, 2022, 10:58:37 AM »
The 8011 also had a lighter crankcase and was availible with the "P" head for precission areobatics. The 4011 had the stronger crankcase and front case and was basically bullet proof even in modified form with pressure venturi on 10% nitro.

The ABC 4050 and 4055 ABC stunt had the 4011 crankcase bored out to fit the ABC liner which was fine for the intended aplication. In modified form for racing the clylinder of the 4055 would burst apart and send the top of the engine flying.

I was working with Mecoa to address this problem. Mecoa is sitting on a run of 4055 crankcases castings that have a thicker wall at the know break point but as of yet they have not done the finish machining on them. I have one in my shop also unfinished as the racing event for that engine, alas, is no longer flown.

As the story goes, the initial run of ABC engines from K&B were properly fit and ready to go when the decicion was made to loosen the piston fit a little more for the RC market. These were softer aluminum chrome plated pistons taken from the Sportster 45 line, chrome removed and machined down to fit the 4055 sleeves.

This was the death knell of the 4050 - 4055 as the piston fit was not great from the start and then wore out in a few flying sessions. The fix in the mod shop was to get a high silicon piston casting from a K&B 6.5 and machine it to fit the 4050 sleeve. I have one of those too but alas, no where to race it.
 

Motorman 8)
« Last Edit: August 05, 2022, 11:19:26 AM by Motorman »


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