cox tee dee cylinders

and when were the last production runs, the tee dee cylinders dont have spi do they? i read it doesnt offer much gain on the rotor type engines.

My Tee Dees all have SPI. That's right, not as much benefit as the reedies get from SPI.

All TD cylinders have SPI. However, the gain is minimal for rotary valve engines.

Last production run was around 1996 or so. We bought the last 400 sets they had in stock.

so if i bought a tee dee from say 1989, it would have spi, tapered grind, and dual bypasses and 1 booster per side, so i would basically have a venom cylinder?

Maybe yes, maybe no. I would not rely on the year.

looperdude wrote:so if i bought a tee dee from say 1989, it would have spi, tapered grind, and dual bypasses and 1 booster per side, so i would basically have a venom cylinder?

More like a Venom would have a Tee Dee cylinder. But it's impossible to pin down production changes to a particular date. Even if you could ask Roy Cox, you still could not get specific answers because they made so many parts, that when production changes were made, they still had tens of thousands of the previous version that were still being shipped. So sales of new and old parts overlapped. Nobody can answer without guessing. We have had some former Cox engineers, designers and production workers tell us as much.

thats what i was thinking.

Cox International wrote:All TD cylinders have SPI. However, the gain is minimal for rotary valve engines.

Last production run was around 1996 or so. We bought the last 400 sets they had in stock.

I guess the only exception is the TeeDee050 that came with no SPI, as it was not possible due to the use of R/C throttle, and the muffler installed on TeeDee050-s where the engine would not react to the throttle, and inhale exhaust gases from the muffler through the SPI gap...Whenever I tried to use a muffler on a SPI cylinder the performance of the engine dropped dramatically. So I use my SPI TeeDee-s (010, 020, 049 and 051) without a muffler and I am the most unwanted nitro-flyer in the field because electric-flyer folks tend to be irritated by the sound of a TeeDee at a tach of 21+k rpm...which I wierdly love, though.

balough wrote: I am the most unwanted nitro-flyer in the field because electric-flyer folks tend to be irritated by the sound of a TeeDee at a tach of 21+k rpm...which I wierdly love, though.

Electrics.... No noise, no dangerous chemicals. Where's the fun in that?

Jim