Recent engine acquisitions

NEW222 wrote:
Left to right, top row first
OK Cub 049A, OK Cub (model unknown), OK Cub .099, Ok Cub .074

The unknown Cub will be their first model .049.  It is known as the "Long Stroke" model. The case is the same, I believe, as the .074.  The fuel tank as pictured fits both size engines. The first .049 takes a long glow plug wheras all subsequent .049s use a short plug. No parts are interchangeable between the first .049 and the .049B which followed.

I bought on ebay recently, and the postman just delivered this brand new, very early ( early 1960-s) production TD049 featuring:
1. Beautifully contoured No. 4 thin wall cylinder without flats on the top fin for wrench:

Later cylinders were first stepped wall then thick wall and flats on top fins are on these later ones only.

2. Tapered fit piston with tight pinch on TDC. The piston has the balljoint cup swaged into the piston crown, unlike later pistons that have the cup machined from the piston parent material itself:


3. Oiling hole in rod big end:


4. Thin web on crankshaft. Later production runs had the web thickened and a No2 stamped on the crankcase mounting bar:



5. No screen on venturi intake...screens appeared first around 1972-3:



Many of the above design features were changed over time as operating experience and cost cutting efforts dictated, including thick wall cylinder, thicker web, tapered piston- cylinder fit and oil hole abandoned etc.

All in all a nice historical relic I have been looking for long.

Congrats on the find, balogh. No doubt the thinner profile was intended to produce a powerful lightweight engine. I imagine Cox engineers listened to top contestants for comments and resulting metal thickening came as a result for engine improvements.

I still like the older earlier engines, they are classics.

RE: Collection of Cubs-- especially .074. Does anybody have any extensive experience with these. I have a few of them (most in very good condition) and I have yet to run one that will put out any more wind than just an average .049B or A. I can't even find an advantage using a 7" prop. What was the point of this engine?

That is a beautiful engine Andras! I agree the early engines have the purest form. Did you notice the early style Tee Dee head? My QZ came with one, and I replaced it with a new one because it was dirty After looking at the cleaned up engine for a while thinking ”why does it look out of place?” I realized that the early High compression head looks different. It is externally just like a 302, but with the knurling. So I cleaned up and installed the original head, much better.

I have a couple of .051 versions with the step style cylinder (never understood the point of that shape), but haven’t come across one of those really early versions. Maybe I should start browsing eBay too

Thanks GallopingGhostler and Kari...I like the classic contour of thin wall COX cylinders as they resemble the 4-stroke knuckle-head cylinders of old Harley Davidsons.

Kari I read somewhere that when COX realized the weakness of thin wall cylinders and wanted to increase wall thickness, the recess/groove seen under the exhaust ports on the step wall cylinders was machined because the honing tool required that groove. The later tools were different and the groove became obsolete and the thick wall cylinder was born.

Also thanks for calling my attention ho the high compression head on this engine! It really shows a different knurling than what we know on latest HC heads!

.

Duke prototyped the engine as a .049 for Comet, but switched to .07 once production started, after Comet they were sold as a 'hobby' engine and later sold as a .049

Thats my favorite TD .049 and keep an eye for them. The cylinder has 4 boost flute also, no?
Need a similar Medallion to go with it.

Yes it is No4 cylinder with 2 bypass and 2x2 booster flutes. Good luck for finding one they are rather rare find though..

I find them but they always get a high bid so I'm not the only one looking.

Mine was a good deal at 42 bucks plus shipment

ticomareado wrote:RE: Collection of Cubs-- especially .074. Does anybody have any extensive experience with these. I have a few of them (most in very good condition) and I have yet to run one that will put out any more wind than just an average .049B or A.  I can't even find an advantage using a 7" prop. What was the point of this engine?

Don't have one of those, but have several A.C. Gilbert .074 Thunderheads. That was fairly typical for the day that the .074's produced the power of a Cox .049 Babe Bee, another reason why Cox dominated along with Cox's lower price. This is why Walt Musicano's Scientific CL designs designated engine range from .020 to .074. As in all, engines are usable if fitted to the right airframe.

Mudhen wrote:

KariFS wrote:...I have a couple of .051 versions with the step style cylinder (never understood the point of that shape)...

Cox used the stepped, (grooved,) cylinder to provide a bearing surface the speed control sleeve.
It started with the throttle controlled P-40, (350-2,) that was released in mid-1968.
At the time it was referred to as a "Special Cylinder."

Yes, I understood why the thick part appeared, but not why the thin area remained

balogh wrote:
Kari I read somewhere that when COX realized the weakness of thin wall cylinders and wanted to increase wall thickness, the recess/groove seen under the exhaust ports on the step wall cylinders was machined because the honing tool required that groove. The later tools were different and the groove became obsolete and the thick wall cylinder was born.

That is probably the reason, makes sense definitely. Many times when there is an odd feature like that, one that does not improve the aesthetics, and does not make sense when engineering of the final product is considered, the reason lies somewhere in manufacturing and tooling.

I always figured, if you need the cylinder to be thicker at the exhaust port area than at the bottom flange, why still machine a groove and a flange Engineers are lazy, drawing extra lines is laborous, manufacturing hates extra phases in machining and bean counters hate unnecessary cost. But if they had an expensive honing tool or a fixture, they probably wanted to get all the ”mileage” out of it before scrapping.

Learn something new every day

I got home last Friday and my wife asks, ”have you ordered cigars from America?”. I am like ”uh... huh? What?”

Here’s what I found:



Turns out it is a surprise present from a fellow in Texas, here’s what was in it:



Three cool little engines and a stack of propellers. A Tee Dee 049, a Black Widow with a 5-fin Texaco head, and what looks like a Norvel AME 049 or 061. And check out that military patch, it is the patch of the ”Company E "Chaos," 227th Aviation Regiment, 7th Squadron, 17th Cavalry Regiment” that operate the ”Gray Eagle” UAV. Looked it up, really fascinating technology, a diesel-engine-equipped unmanned aircraft that can operate up to 50 hours, either reconnaisance/overwatch operations or actual attack missions.



The Tee Dee has an aftermarket NVA with the 128tpi needle, always wanted one of those!



And the AME, never seen one ”in person” before. That rectangular intake is huge! The sandblasted case and overall ”no nonsense” functional attitude is very cool. The engine is also surprisingly light compared to the other two Soviet engines I have (a CSTKAM and a MAP3 ”MARZ”, both 2.5cc).



Here are the propellers, the two small ones look like they have been modified, possibly for speed flying?

Also, stuck in the tape of the bubble wrap there was a little vintage Top Flite nylon prop, not in the pictures. I already mounted it on my Space Bug Jr, you’ll see it in an EotM pic cavalcade soon

So once again, big Thanks to our friend in Texas!

(Not sure if you wanted to stay anonymous, so I withheld the name for now)

Begs the question, does Santa live in Texas............only he arrives via the mailbox rather than the chimney. Either way it's fun times.

Looking at what you received it’s pretty easy to figure out where it came from.

I have a hunch that same Santa gifted me a Super Tigre .35

Yea Looks Fast to me Great stuff man i think someone is trying to get ur butt in the Air !! I meant to say Help U !! Man That's just Christmases E

Out here in po dunk rural Texas I have two post offices to use... my county road is exact half way between the two....Lampasas PO serves 7000+ town and usually has a line....the Kempner PO serves 1500 folks and most days I am only one in line

All of our family is distributed around the globe.. so we mail out a lot of stuff every month...in fact we have a budget item called postage

Over the years now as CEF guy I have sent gifts around the world, Singapore, Australia, Germany, England...and now Finland...my postal lady at the Kempner post office and I have great fun figuring out the right customs form and the correct set of lies so the recipient does not get slammed with what ever value added tax (VAT) or country specific import tariff on the items

and one must be crafty and vague else claiming one thing but sending another becomes a federal and international crime...and that dear sirs is why on a customs form they demand you the senders perfect identity and contact information....

so the gift went as "misc model airplane repair parts" value under $20 US....there is/are no lies in that declaration....

I follow 5 different forums...lots of between the lines things to learn... we all know some poor customer that did not get a model airplane engine from e-bay because they (we still do not know who THEY is/are)  confiscated it as not exportable or not importable for what ever stupid reason

Thus it seems to me not very wise to declare any internal combustion engine as a complete model engine

I am confident if some customs agent arrested me---- my lawyer could easily describe each of the items I sent as repair parts listed in multiple catalogs as replacement or repair parts...for a lager assembly

So Now I am just rambling...wet cold day

If you are ever the recipient of one of my boxes of goodies...Trust me! I do not need any reciprocal gift...if you must ----pay it forward

CRS is such that I should have kept a list--- as right now, I do not remember if I have sent any thing to Budapest Hungry

Thanks Fred! I will pay it forward, someday, somehow

My friend- and flying buddy while he was assigned to Fort hood --is Sean McEntee...

His dad is a member here but does not participate in CEF --he had items he thought we would be interested in to buy

Any way, Sean is now a E -7 platoon sergeants who fly's the Grey Eagle (and others) UAV, and he has an impressive (OK this is not PC ) number of successful missions...you read between those lines

His last deployment he took a Brodak electric Ring Master ARF and flew it on the RM marathon week end

That patch is from his unit here at fort hood...He is now assigned to Ft Carson Colorado

I was in the 1st Cav  4th Aviation Brigade, 227th Battalion, twice in my career... Sean sent me several of those real cool patches...was pretty sure KariFs would get a kick out of it and did exactly what I assumed...googled it...too cool

fredvon4 wrote:

…….CRS is such that I should have kept a list--- as right now, I do not remember if I have sent any thing to Budapest Hungary

Yes Fred you indeed sent me a COX 09 muffler plus one for an Enya and I remain obliged for your generous gift!!!

Got theses a few weeks ago , haven't had time to play with them Yet I was getting down to only a few Pee Wee's  

Now i got i think 4 of the .049 medallion slide throttled ones