*Cox Engine of The Month* Submit your pictures! -November 2016-

Extreme TD .09

Engine has many custom performance enhancements

- High speed performance crank
- Valentine Turbo Plug Head / OS Turbo Plug
- Kustom Kraftsmans 128 tpi NV
- KK big bore venturi
- Throttle sleeve - cut for SPI
- SPI Cylinder - dual bypass ports (not the RC version)
- Valentine .049 bullet spinner tapped 6-32 thread
- KK .09 back plate with fine hole pressure tap
- Aluminum carb body
- Phenolic thrust washer (for elect. starts)
- Master Airscrew 7x6 modified to 5x6N


   

https://www.youtube.com/watch?v=BqrjoTlrm3E



Published on Jul 2, 2016

Best level pass 143mph / per prop calc / 5.25x6.25E
Wavescope: 232.07 kmh / 144.2mph /down wind
The reading was taken at 1.52mins into the vid.
Temp 96F (16,975 rpm at launch) 30% nitro

I have the TD .09's the TD RC .09's  and the Medallion .09s
Cox made special glow plugs for each. If you have a TD Glow head mount
and flip the prop to feel the difference in compression. Out of the 3 types
the TD Glow plus has the most compression feel. Best plug if you have low
nitro or need top rpm or out to do some cold weather flying. On hot days
you can use up the Medallion glow plugs and still see good performance.
Use less compression for big props of course less stress on the pin, crank,
ball socket and rod. I have gone from 4 mins to around 11 mins with a bigger
prop when run time is desired with a 1oz tank.

A .09 engine will still function quite well with the glow head plug adapter style
over the TD Head.  The smaller displacement .049 can have losses, just seal the
threads with grease prior to installing the head adapter and glow plug to insure a
good seal. Make sure the adapter is seating on the head gasket. The advantage
using standard glow plugs is you have a wide heat range you can choose from and
of course some brands are better than others. If you have a large hole where the
element sits in you want to discard for a brand the has paid attention and only has
the minimum size possible to fit the element in to help increase compression.

I prefer the turbo plugs, they seal before the threads so there is no air leaks to
worry about if properly installed.

Mine is a special glow plug adapter head made by Mr. Valentine
The threads do not go all the way through the adapter.