Cox restorations for the week

Thanks Jason ; Its funny some can take it and others cant if you leave them too long in the denatured alcohol, forgetting and not having the time gets to be a problem ! You engines look Great !! and you got a bunch done in just a week Eric

getback wrote:Looking good Jason , what are you using to clean with if you don't mind me asking , I been using denatured alcohol and recently have been getting a tarnish after soaking only 2 day on the BB cases and that's a pain to get off ? the tanks are no problem chuck them in a drill and some worn out sand paper then polish.      can't see it that well in the pic but its there I can sand it out but a lot of work to get in the recess places. getback

Doesn't denatured alcohol contain water? Water can cause aluminum to oxidize or tarnish.
  I use old fuel. Any fuel over 1 year has lost most of it's nitro and makes nice engine cleaner. Besides most of my fuel is over 15 years old. Be careful  if you use radiator fluid because the fumes bother some people and the fluid is toxic to dogs.

P.s. Check the denatured alcohol label for contents. An additive may be water.


Happydad

I think your thinking of isopropyl alcohol that can have up to 50% water added. Denatured alcohol is ethanol with usually methanol added. Adding water to ethanol would still make it drinkable of which the TTB would not like.

Jason_WI wrote:I think your thinking of isopropyl alcohol that can have up to 50% water added. Denatured alcohol is ethanol with usually methanol added. Adding water to ethanol would still make it drinkable of which the TTB would not like.

But, like Rusty pointed out if you leave parts in alcohol exposed to air too long it can take moisture out of the air. I have seen parts like copper cleaned with denatured alcohol oxidize quickly again after cleaning. Anything left in the open can absorb moisture out of the air, especially liquids. I always use oil based cleaners on my engines to be safe.

happydad  Happy Thanksgiving

More restorations this week. Can you spot the early babe bee with the 3 piece piston?

The backplate on the top right engine looks right but other things don't add up, so I'm guessing the engine below it, middle right, behind the Pee Wee.

Rod.

Looking Good , I will guess the one above the red TD 51 ? getback

My X-Ray vision does not work over the internet, so I can't see the internals. I'm gonna guess it's the top right engine with the non plated backplate?

I'd say 2nd row right before the Pee Wee, it appears to have the smaller intake without screen and the larger turning knob on the needle valve.

Yep, its the middle engine just behind the Pee Wee. I has the bright zinc chromate backplate and no Cox logo on the backplate. Also no provision for a screen either.

Good "Where is Waldo" analogy.

yep, it was one of two with the large needle, the other has the newer "brass" backplate.

Oldenginerod wrote:The backplate on the top right engine looks right but other things don't add up, so I'm guessing the engine below it, middle right, behind the Pee Wee.

Rod.

As I mentioned, I felt that the backplate on the top right engine looked to be the right colour for an early engine, but my final choice (the correct one) was due to the shape of the intake region (hard to see), crankcase nose, thin walled cylinder & large needle knob. I becomes a little difficult because after all these years many engines have been mixed & matched. I have 2 of the first-run Babe Bees & for some reason haven't been able to get them to run.

Rod.

More restorations this week. The killer bees are real. One is pre '96 the other is post '96. Got them in a RC Groups lot a week ago. Could see the double groove .051 piston in the lot pic.

Jason_WI wrote:More restorations this week. The killer bees are real. One is pre '96 the other is post '96. Got them in a RC Groups lot a week ago. Could see the double groove .051 piston in the lot pic.

Nice Jason, Very Nice. I would venture a guess they set you back a pretty penny or 2. especially the 2 original KB's.
I am very envious, but on a strict budget. Pay the bills 1st, buy food 2nd, spend the rest on gas for the cars. Retirement has it's benefits and it's drawbacks.
  Show us more as you continue your restoring project.

happydad                    

NICE GROUP !! you are just having way too much fun lol I have got to get some cleaned and back out there for sale sold all but two . I was eye balling my engines on my planes hanging around and they are not SHINNING getback

Great Collection !!

Jason_WI wrote:More restorations this week. The killer bees are real. One is pre '96 the other is post '96. Got them in a RC Groups lot a week ago. Could see the double groove .051 piston in the lot pic.

Nice assortment Jason and good job on the clean up. Recently I came to the opinion that it is just not worth collecting older non-Cox 1/2-A engines for use. The reed valve Coxes are the most powerful sport engines available, exceeding legacy sport rotary valve engines of the their day.

Why even the Pee Wee exceeded the performance of some of the .049's available in the 1950's / early 1960's. The novelty of legacy stuff is wearing off as I get older. And for RC planes that use an .020 Pee Wee or Tee Dee, one can take a Sure Start, add throttle or put mild prop backwards or use a clamp exhaust restrictor, or have fun with that plane with a little more zip.

More restorations for the week. The TD .09 is definately just a runner. Not pretty with the mounting holes drilled or the tool marks on the case and drive hub. I had wanted to swap the crankcase with the Medallion .09 but the Medallion .09 crankcase had a larger diameter crankshaft. Sometime in the early 80s Cox must have increased the crankshaft diameter on the Medallion .09. Not all .09 crankcases are the same.

One Queen Bee has a custom muffler. It is a later one with two bypass ports and 2 boost ports milled in one on each side. The QB with the original muffler only has to bypass ports.

Jason_WI wrote:More restorations for the week. The TD .09 is definitely just a runner. Not pretty with the mounting holes drilled or the tool marks on the case and drive hub. I had wanted to swap the crankcase with the Medallion .09 but the Medallion .09 crankcase had a larger diameter crankshaft. Sometime in the early 80s Cox must have increased the crankshaft diameter on the Medallion .09. Not all .09 crankcases are the same.

Joe Wagner, engine guru and columnist for various magazines one time had an article on how he restored engines that had broken mounting lugs by making cardboard forms and J.B. Weld to make up the missing portion. I suppose you could fill the mounting holes with J.B. Weld and redrill them. For me, I'd practice on a junk case before trying it on another.

Regarding the tool mark case nicks, I've used a fine file to remove burs and high spots followed with Mother's Mag and Aluminum Polish cream to help remove or defuse them. Cleaned up a couple Enyas and an OS Max .40-FP that had that problem quite nicely.

One Queen Bee has a custom muffler. It is a later one with two bypass ports and 2 boost ports milled in one on each side. The QB with the original muffler only has two bypass ports.

That is interesting. I never inspected the porting on mine, it is one of the earlier. I got it thinking it would make a nice RC engine, but had a bugger of a time attempting to start it with the Cox glow plug. Later I found that if I had replaced their plug with another I'd have better luck. That engine was a disappointment because of its heavier weight. I never understood why Cox didn't simply upsize the .049 reedie and made a larger, lightweight Sure Start style of a motor with a lightweight exhaust throttle muffler. I'm sure it would have been a hit with more power output than the .049 sport reedies. If they matched the bolt mounting pattern of the Cox .049 tank reedy, it would have been a sure hit. It apparently didn't sell well and was discontinued not much long after, IMO. It was then that I figured that Cox was on its way out.

Another oddity was the .049 R/C Bee. It was a reliable, great sport engine but used an odd thinner internal clunk fuel line that was looped to provide clunk action. It was sold only for a short time, and the tubing wasn't long lasting. I ended up replacing it with thicker silicone fuel line loosing clunk action. The motor was well worn with many flights onto its second cylinder. Since I flew it on a single channel Minnie Mambo with Ace Pulse Commander and Stomper Actuator for rudder and KRD sequential quick blip throttle servo, there was no need for clunk action. I found rudder only a real blast to fly with Minnie. It would loop like crazy with its short coupled elevator to wing.

Jason_WI wrote:More restorations for the week. The TD .09 is definately just a runner. Not pretty with the mounting holes drilled or the tool marks on the case and drive hub. I had wanted to swap the crankcase with the Medallion .09 but the Medallion .09 crankcase had a larger diameter crankshaft. Sometime in the early 80s Cox must have increased the crankshaft diameter on the Medallion .09. Not all .09 crankcases are the same.

One Queen Bee has a custom muffler. It is a later one with two bypass ports and 2 boost ports milled in one on each side. The QB with the original muffler only has to bypass ports.

Jason, That .09 Tee Dee, is an older, early model .09 with a thin wall cylinder. The cylinder looks to be in great shape. The TD .09 is one of my favorite engines because of the power output. I keep a close eye on ebay and the older models are somewhat rare. Nice catch. Andy

Question : the BB top right thin neck crank , Is that considered a product engine I haven't been able to find info on them , shows BB as the bottom right ///I Know its an early version and people will buy those before the other. getback

getback wrote:Question : the BB top right thin neck crank , Is that considered a product engine I haven't been able to find info on them , shows BB as the bottom right ///I Know its an early version and people will buy those before the other. getback

Regarding crankcase taper year discontinued for straight untapered, not sure exact year, but it must have been sometime in the early 1970's. Engines I have (purchase date not manufacturer date) up to 1971 have the taper. Ones I picked up 1974 or 1975 on did not. (Just checked a Cox 190/290 postage stamp back donor engine from a Cox RTF I bought and crashed in 1971, it has the taper.)