tewitt1949

Hi All, I'm somewhat new to this forum but I have question and I can't fine the answer by searching. How does the tee dee .051 compare to the tee dee .049 as far as performance, fuel consumpsion, weight, etc. Thanks Terry

air-madness

I think the .051 is basically a bore-up type of thing going on with that particular engine. I'm pretty sure the engines are the same. Perhaps one of the little engine guru guys on here will be able to answer your question more clearly.

combatpigg

My Feedback: (3)

Terry, one has a red carb body, the other black. That is the main difference. Apparently there are / were guys who would act like little girls if you tried to enter a .049 powered plane in A class competition. Cox then came out with the .051 to satisfy the engine size technicality. About as silly as it gets, a good example of grown men taking a little boys' game too seriously.

ffkiwi

There IS no difference in power and performance between the 049 and 051. The two variant were produced to allow a 1/2A model to be flown in Class A. The only physical difference between the two is the cylinder bore-0.406" for the 049 and 0.410" for the 051. The 051 piston has a shallow groove around the lower piston skirt just above the base, to allow identication, but this serves no other purpose. A factory correct TD 049 has a black carburettor housing and a TD051 a red one-but these are interchangable-so are not a reliable indicator, since this housing quite often splits in use-usually from users tightening the venturi too much-and often gets replaced with whatever the user can find-a black or a red one.
The WHOLE POINT of the 049/051 split is that there IS no difference in weight or performance between the two variants. This 'split' approach is a long established US practice, going back to the 40's=hence we have 049/051, 19/21, 29/32, 40/41, 49/51 and 60/65-though the larger capacties are less common, and some of the 41's are 'specials' ie produced to special order and not available thru normal commercial outlets. See my article in the current edition of 'Free Flight Quarterly' (plus the next issue)
With all, the intent remains the same-to allow a model (and it need not be just a plane model) to compete in two separate displacement classes simply by replacing the engine.

'ffkiwi'

rainedave

My Feedback: (1)

Very clear and concise, ffkiwi. As someone who has trimmed a lot of free flight models I can back up the importance of no difference in weight and power. It's crucial that a model fly exactly the same with either engine.

http://www.freeflightquarterly.com/ffqcurrent.html

I see there's an article on the Civy Boy in there. Hands down my favorite NosGas design.

tewitt1949

I see. Thanks a lot for explaining and giving the great difference/non difference between the 2.

ffkiwi

Not one of mine RainDave-but in NZ we have a Dec 1960 cutoff for the Nostalgia era-so we have another 4 years of designs to pick from than you guys in the USA. My vote goes to George Fuller's 'Dixielander' [I have 4 underway simultaneously at present-though Lord knows when they'll get finished!]
In our club (Christchurch MAC) we have one of the originals-Ian Henry-still flying F/F at 86+-he is a contemporary of people like Sal Taibi and Carl Goldberg etc-and still at it-despite starting in the 1930's! He has quite a stable of Civy Boys in various sizes plus a few variants such as the Civy Hearse-in fact he flew several this morning out at our field! Actually this morning he was trying to trim a TD 049 powered KK Gaucho-which was a lot hairier on the TD049 than on the usual 1.5 diesel...

In terms of popularity here in NZ, US designs predominate in the Vintage classes (< Dec 1950)and UK in the Nostalgia (Jan '51-Dec '60). Most popular Nos-tricky-probably a George Fuller 'Stomper', or perhaps a Barry Wheeler 'Eliminator'

'ffkiwi'

rainedave

My Feedback: (1)

That sounds like a great club. Here in North Carolina there just aren't enough good fields for ff.

Another of my favorites is Wensel's Stardust.

Yep, the 12/31/56 cutoff was in large part done to exclude dominant designs like Cunningham's Space-Rod.

Speaking of UK designs, are Gaster's Gastoves popular in NZ? There's a ton of building in those, but they're very streamlined.

David