Cox Fuel Mods, Converting Medallion to Tee Dee, onboard igniter wiring to engine

PeterJGregory wrote:I have seen forum-ites mentioning that the Tower Hobbies Cox Fuel is, ironically, not good for Cox engines due to lower than necessary castor oil.
Is it straightforward to just add castor oil, like 3% by volume more?

I bought a used Tee Dee 049 except it turned out to be a medallion. Is it straightforward to just replace Delrin body with a Tee Dee version and add a Tee Dee needle valve/spray bar and aluminum throat? (sounds like as many $ as the engine cost me(!))

I was  reviewing the Guillow's Bellanca Cruisemaster plans and they show the Cox engine glow head wired to the outside of the cowl that totally enclosing the engine. Anybody with 1st-hand experience about how to set that up so it is reliable?

Many thanks in advance,
Poughkeepsie Pete

Cribbs74 wrote:Cox super fuel has 18% oil and of that 90% is synthetic and 10% is Castor. General rule of thumb for these engines is 20% oil with at least 50% being castor.

Pretty much if you add castor to bring it up to 50% you would end up with glue.

The crankshafts in the Medallion and TD are very different as well as the cylinder porting. So you can't just change out carb/venturi assemblies and expect TD performance from your Medallion.

Ron

RknRusty wrote:I agree with all of the replies so far. You might as well keep it as a Medallion, which is a fine engine and much less finicky about pulling fuel from a tank than a Tee Dee. Though it doesn't develop as much power, it's still stronger than a Bee, and a nice addition to any inventory of Cox engines.

As for your Guillows question, I can't offer any help. Maybe someone will notice it and answer. If not, start another thread about that specific question.
Welcome to CEF.
Rusty