Cox Tee Dee .049 engine
#1
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Cox Tee Dee .049 engine
My latest purchase I got in a lot of engines. It's a custom single exhaust port made from a Cox factory blank, duel bypass cylinder with the bypass ports set at an angle vs vertical, no boosts, standard high compression glow head, Torpedo 5/3 prop running Sig 35 fuel. I wish I knew who built it.
#5
RE: Cox Tee Dee .049 engine
A buddy once told me that if you don't have to reset the piston after every visit to the flying field, your not spinning it fast enough. Me, I tend to keep them a bit slower than the one in your pic. I love to see other folks' engines spin like that, though.
Neat engine, btw.
Neat engine, btw.
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RE: Cox Tee Dee .049 engine
Fastest I ever had a TD 049 turning was 25,400-on a DC 5-1/4x 3-1/2 plastic-sounded fantastic-and didn't fly the model worth a pinch of..........all noise and no thrust-the soft styrene blades used to wash out till almost zero pitch.......and yes I did have to reset the socket afterwards................ It was a fairly std TD-but with the exhausts fore and aft-that a few people claim give better scavenging-and shimmed with the KK cylinder shims as per his recommendations. IIRC it might have had a KK shaved head on it as well-but no porting mods or anything else. I think I still have it..........in a Payload model tucked away somewhere.
'ffkiwi'
'ffkiwi'
#7
RE: Cox Tee Dee .049 engine
Yes, props certainly vary a lot in terms of their developed thrust and needed power. The cox props are among the highest in terms of requirements but also deliver thrust even in the 5x3 size.
I don't think I have ever seen a "Torpedo" prop though. Is it a Tornado Grish perhaps? They are quite low in load compared to other brands. You could try a cox 5x3 for a better comparison to others, or simply run a regular TD on the same fuel and prop.
I don't think I have ever seen a "Torpedo" prop though. Is it a Tornado Grish perhaps? They are quite low in load compared to other brands. You could try a cox 5x3 for a better comparison to others, or simply run a regular TD on the same fuel and prop.
#8
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RE: Cox Tee Dee .049 engine
1/2A Control line planes were pretty tiny and Cox 5-3 props on TDs made them go like rockets up to 70 mph on 35 foot lines.
Same apparent speed as a .35 powered plane doing 100 mph on 60 foot lines.
The Grish 5-3s we called "White Trash" because they were inferior to the Cox props. In Combat, there is no guessing as to what works best. The proof is right there in front of you.
Some guys would cut the 5x3s down to 4.75x3 and get well over 26,000 rpm on the ground but the ball sockets quickly failed. You can get away with it longer with a shaved piston.
The Grish White Tornado props were still OK sport props.
Same apparent speed as a .35 powered plane doing 100 mph on 60 foot lines.
The Grish 5-3s we called "White Trash" because they were inferior to the Cox props. In Combat, there is no guessing as to what works best. The proof is right there in front of you.
Some guys would cut the 5x3s down to 4.75x3 and get well over 26,000 rpm on the ground but the ball sockets quickly failed. You can get away with it longer with a shaved piston.
The Grish White Tornado props were still OK sport props.
#9
RE: Cox Tee Dee .049 engine
For a while you could buy blank cylinders from Joe Klause or Dale Kirn or somebody. We milled all kinds of port shapes and they were all about the same as a dual port Tee Dee. One Schneurle one worked well with a pipe and a brass outlet brazed on the back until it wore out a few pistons. I think we used a Cox 5 1/2- 4 cut to 4 3/4" and shaped the tips to look pretty for the 1/2A speed planes. 80% nitro and Klotz/castor. I think a lightened piston would do a lot of good for the Cox stuff. I was going to turn the inside of a piston a bit bigger while holding the rod, but thought life is too short. The .051 pistons in a Baby Bee would shake like crazy proving my theory that they are on the verge of being too heavy. The ball socket would last longer with a lighter piston and the cranks maybe wouldn't break as easy.
#10
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RE: Cox Tee Dee .049 engine
The late Gene Hemple, who wrote the Model Aviation CL speed column for 14 years, and held a record or two, made cylinders like that. As, said, so did several others. I'd love to get hold of some blank 09 cylinders to try to make up an engine for CL endurance.
#11
RE: Cox Tee Dee .049 engine
I think the AP Hornet .09 would be a better candidate for that. It is a good start to change things up. I made a couple of exhaust extensions for them to use a pipe instead of the nice looking but power robbing muffler that comes with it. I had to buy a die for it. Maybe the cyl. came from Gene Hemple it was in the late 1970's I think.
#12
RE: Cox Tee Dee .049 engine
jsesere,
What kind of plane are you putting the engine in that you need so much RPM? IMHO, up the prop size, lower the RPM a bit, and enjoy the engine.
If you really need the RPM, consider getting a more modern engine that can handle it.
I THINK I read that Kustom Kraftsmanship (KK), (Klause and Kirn, as stated above) had blank cylinders available, but that was years ago. Then again, the TD is a 50 year old design.
Good luck with you TD.
George
What kind of plane are you putting the engine in that you need so much RPM? IMHO, up the prop size, lower the RPM a bit, and enjoy the engine.
If you really need the RPM, consider getting a more modern engine that can handle it.
I THINK I read that Kustom Kraftsmanship (KK), (Klause and Kirn, as stated above) had blank cylinders available, but that was years ago. Then again, the TD is a 50 year old design.
Good luck with you TD.
George
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RE: Cox Tee Dee .049 engine
Hi Mr Cox I have a Question for you, I have 3- 5x3 tornado / grish white props with black lettering and black stripes, 2 look to be new and 1 is slightly used, are these props concidered collectors items ? I figured you would be the one to know and what do you think they may be worth, I would not use them as i bought these back in the late 60s early 70s, but they would look nice on a old cox eng for a display. Thank you for your time, Chellie
#14
RE: Cox Tee Dee .049 engine
I'm sorry, I wouldn't know much about their collector value, I'm a mere user of 1/2a stuff and they're not very special in terms of usage or performance as far as I know. Who knows what the odd collector might think though.
#16
RE: Cox Tee Dee .049 engine
I used to use them and the yellow tornado props because you could crash, and do touch and goes with control line on the pavement and they wouldn't break. I still have some left, that's how tough they are. I had to throw out a few because of age. They would get soft and brittle if you bent them back even just a little they would break. I don't think they would be worth more than a buck or two. I am not a collector though. Just an addicted user. I got a clear nylon one at Toledo for a dollar, and thought it was a collector thing too. It just looked cool and I had never seen one before.
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RE: Cox Tee Dee .049 engine
Thank you for your thoughts on these vintage props, I listed 2 of them on Ebay for 9.95 , see what happens i guess here is the listing if anyone is interested, Take care and Have fun, Chellie
http://www.ebay.com/itm/2-Rare-Vinta...item20bf76f457
http://www.ebay.com/itm/2-Rare-Vinta...item20bf76f457
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RE: Cox Tee Dee .049 engine
We Have used props for utensils when at the flying field during a BBQ when people forget to bring the Utensils like they were suppose to they work Great for spreading Mayo
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RE: Cox Tee Dee .049 engine
I bought these props back then, because i was going to get into 1/2A combat with Foam Wings, and I was talking to a few people at the flying field at Whitter Narrows, and back then, these props worked the best on a 049 TD engine with a Bladder tank, I could not belive how much power and speed those motors had, from a distance, i thought they were flying 40 size engines in those combat planes, as the combat planes were rather big for the 049 engine size.