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Building Tips and technical articles. => 1/2 A building. => Topic started by: Steve Thornton on January 20, 2015, 10:44:11 AM

Title: Metal carb body for TD engines
Post by: Steve Thornton on January 20, 2015, 10:44:11 AM

After reading some of the threads, it seems that a metal carb body will be a good idea for my TD's.  Any opinions or complications?  Are there any available...can't seem to find one on the web?
Thanks for any help.
Steve 

Title: Re: Metal carb body for TD engines
Post by: Tim Wescott on January 20, 2015, 11:22:18 AM

It seems like a nifty idea.  I've never heard of such, but I'm not involved in any competition classes that would use it.

I'm pretty sure that such an animal would need to have O-ring seals.  Moreover, the "D" shaped hole would probably have to be broached: it'd be an interesting machining challenge to make it accurately enough to be worthwhile.

Title: Re: Metal carb body for TD engines
Post by: Andrew Tinsley on January 20, 2015, 03:07:35 PM

Yes they are available, I got mine from someone in NY state and it is now running well on an .O9 Tee Dee. I will try to find the guys address. I have it somewhere!

Andrew.

Title: Re: Metal carb body for TD engines
Post by: Phil Krankowski on January 20, 2015, 07:32:31 PM

There is no D to the hole, it is just turned, maybe reamed.  There is an o-ring.  They work pretty good, but make the intake more sensitive to being bored out in my experience.  I had a bored out venutri on the plastic body and the engine ran fine on pressure bladder, but on the aluminum body it was a pain with the same bladder system.  I switched to a new stock venturi and the engine ran fine again, better than ever in fact.  I don't know if it is making the same power as before but it is pulling a baby flite streak just fine.

I have no idea what the venturi bore was, but it seems to be larger than recommended.  A 1/8 inch drill bit floats in the bore. 

I was initially concerned about the body rotating and changing the engine timing, but this won't happen as the timing is set in the case.  As long as the body is lined up close enough that it is not getting obstructed there is no possible change.

Phil

Title: Re: Metal carb body for TD engines
Post by: Steve Thornton on January 20, 2015, 08:31:14 PM

Man are you guys smart!  My logic was centered around the fact that I still crash a lot and I read that the plastic gets smashed up and bends the needle. Andrew please don't waste a lot of time looking for the address, I'm sure that there will be one on EBay sometime.  Phil what line length do you use for the Flight Streak?
Steve

Title: Re: Metal carb body for TD engines
Post by: Larry Renger on January 21, 2015, 08:24:05 AM

Cox International sells the units.

Title: Re: Metal carb body for TD engines
Post by: Phil Krankowski on January 21, 2015, 12:33:00 PM

35ft in my side yard (space limit) 45ft if I have the space.  I run 20# power pro in either case.  It is a little crazy on the shorter lines, but manageable. 


I got my venturi diameters here
http://www.coxengineforum.com/t4526-tee-dee-049-051-venturi-hole-size-question?highlight=venturi+diameter

Phil