I have recently dug up a couple of 20year + old Baby Bee Cox engines from my childhood days. They require a battery to start and although I can remember what they looked like, I cannot remember the voltage or current rating. I have been unable to source a suitable batter in South Africa so am looking to build a voltage regulator which will be powered from a 12 7AH battery. What voltage is required and how much current does it need to deliver ?

Just like the removable glow-plugs, these operate around 1.2 - 2.0 Volt. Your 12V field battery will fry it (literaly) faster than you can say OOPS. I single sub-C sized NiCd will provide over a dozen starts between charges. These days, if you buy a model with these engines, it comes with a battery case which holds 2 D-size Alcalines (in parallel).

How much current? I don't know, but I would guess a regulator which can handle 2-5 Amps should do. The glow plug will only draw as much as it needs, but the regulator has to be able to handle it without burning up.

I'm not sure about the old glowheads. If they are, in fact, 1.5v, then you can use C or D cells. I seem to recall seeing old glowheads that were a higher voltage though. You can try hooking up a 1.5v battery and seeing if it works, or looking to see if you have a bright glow or not. (heck, if they are that old, you should check to make sure they still light anyway.)

I think (not totally sure though) that a 1.5v glow plus pulls about 2amps normally.

My 20 year old Cox works fine with 1.5 Volts.

Since these small engines rarely have a muffler, you can look in the exhaust port(s) to see if it glows a bright red. A dull red may not be enough to ignite the fuel. Too bright, and it'll burn out quickly.

Cox heads are 1.5 volt rated and the 1.2 works just fine. Many people do hook a couple of small cells in series in an attempt to acheve easier starting and this is a mistake beyond the already mentioned fact that your plugs will not last very long.

The most common control we have of our glow engines ignition timing is the glow heat. A hotter plug will advance the ignition timing and a cold one will retart the ignition. Since easier starting is by retarding the timing and an advanced timing will cause starting problems. When you up the voltage in a Cox head you increase starting difficulty.

The best ignitor if you don,t have the Cox or one of the aftermarket clips is just a couple of 'C' or 'D' cells Nicd or alkaline with a short wire of at least 22AWG soldered directly to the cells in parallel and a couple of aligator clips for hookup.

Works just fine, as a matter of fact controlline team racers use a hot glove for pitstops. The pitman has a couple of cells taped to his arm and a glove with contacts attached to the index finger and his thumb. He just wraps his finger under the crankcase and his thumb on top of the plug . A single squirt with a bottle and a quick flip results in refuel and relaunch in seconds.


John

I run 40+% nitro in those engines. They run best on it. They run bad on low nitro.