Five years ago a member of the Cox Engines Forum posted about a horribly abused Cox TD .15 for sale.  It looked like it had been sitting out in a field for about a decade.  I bid on it and got it for $11.







It sat in a baggie until late last year.  I disassembled it and started looking for rebuild parts.  I had looked at what it would cost to do it back in 2019, and it would have cost $85 in parts.  I put it off for later, but now there are not enough parts to buy online available to rebuild it.  So, I decided to give it the same treatment that I did on the bladder conversions I previously posted here on .049 and .09 Medallions. 





It was cheap and easy, as I only had to buy a $13 Medallion .15 venturi body from MECOA.  I used a normal Cox .049 product engine NVA I had, soldered into a brass tube the same as on the previous conversions.  I was hoping to get somewhere between Medallion and TD.15 RPMs as this is a hybrid.  Initially I was only getting 11,400 RPM.  Instruction sheets for the TD and Medallion say that on an 8x4 prop I should get 13.8K on a Medallion and 15.7K on a TD.  I opened up the throat of the venturi and ran it today.  I am now getting 16.4K on the 8x4 prop.  I’m calling it good.

So, if you ever find yourself with a TD.15 and no venturi parts, this is one  way to go.

Mark

Mark,
That is just remarkable work!

Do you remember there was chatter on CEF about using the AP .061 carb on Tee Dee .049 bodies? In fact Juan in PR has one he's getting ready to try. I seem to remember it was a matter of bushing the smooth case carb with an internally smooth/externally threaded bushing to replace the Tee Dee venturi and spray bar.

I wonder if the AP .09 carb would work on Tee Dee .09s...and if AP .15 carbs would work on the Tee Dee .15s. I may have carbs from those two APs kicking around. Care to trade measurements?