groran

My Feedback: (76)

I see at some vendors, they have DLE ignitions, some say #4, #1 and so on. Some say for this engine and that engine. Some say that DA engines HAVE to have their ignitions only. My question is, whats the difference? I know that some of them have different cap sizes, two cylinder, etc. Can I use a generic ignition as long as the cap fits and the sensor passes over the magnet? Some flyers say the different numbers are different advance curves. I figure as long as the cap fits, the sensor passes over the magnet, your ok. I also believe all modern ignition systems have auto advance in most if not all systems. Any info appreciated, thanks

av8tor1977

My Feedback: (6)

CH Ignitions used to be the most popular and used, and many of them did not have auto advance. They had a separate plug in unit called "Synchro Spark" that you could buy to make a non-auto advance unit into an auto advance. They also sold units with Synchro Spark, or auto advance built in. All the RCEXL units that I know about are auto advance. I believe it is the number 4 unit that has a funky advance setup that can be problematic and is not popular at all. Most if not all the other oddball Chinese ignitions are some variation or copy of the RCEXL units, and the RCEXL units are basically a copy of the CH Ignitions. In most all cases, the parts are interchangeable. As you mentioned, the units with a metal cap must be matched to the type of spark plug you have, and that fit is critical for operation without RF interference. The CH units did not use a shielded metal cap, but instead have a shielded spark plug wire that ends in a pig tail that must be grounded to the engine. The CH and RCEXL ignitions are quite good, and I wouldn't recommend the other Chinese offerings. A complete RCEXL system can be had for a little more than 50 bucks nowadays.

The Desert Aircraft engines such as the DA-50, etc., use a completely different system for triggering the ignition, and parts are not interchangeable with the CH and RCEXL types.

There are some other units out there that I am not familiar with, but the above are the most common these days.

AV8TOR

BadAzzMaxx

CH did make a shielded plug cap for the 3/4 hex plugs and was called a Botch cap I believe.

DA/3W/ZDZ ignitions are completely different ignitions systems than the CH style ignitions, They are timed from 3-6 mm before top dead center and to use a CH style ignition with new sensor and sensor bracket you had to drill and tap new threads in the engine to time it right.

About two years ago we deigned and manufacture a system that will allow you to use our ignition without having drill and tap new holes, It is a direct bolt on using existing mounting holes on DA/ZDZ/3W engines.

Milton

earlwb

Well besides the external differences, there can be differences inside. The more simple ignition units had no spark advance. Later they had a simple two step retarded and advance mode built in. Then more expensive units put in advance curves or multiple steps to control the ignition timing. Some differences would exist as they could program in different advance curves for different engines based on the need or requirements. The cheaper ignition modules tend to have a simple two step timing with retarded for starting and advanced for running. More expeneive units may have a advance curve in them. I think most all of the ignition modules now use microprocessors in them and are programmed at the factoryu based on their contract requirements.

Other differences is in the voltage level needed to run the ignition module. A cheap module may only work a 4.8v with 6.0v really being the maximum voltage allowed or the module will burn out. Better modules support 7.2v to 8.4v and sometimes even 12v voltage levels to power the unit with.

The issue can be obfuscated by manufacturers ordering batches of ignition units for a specific engine and leading one to beleive it is special just for it. RCExl for example slaps on stickers for every brand as needed in the contracts when they make them.

But with our model engines a generic ignition module will likely work just as well as the branded version. The advance curve may not be the same, but you may or may not be able to tell the difference.

w8ye

My Feedback: (16)

There are ignitions that are timed statically at 28* before top dead center and there are others that are timed at top dead center

Most all the CH and RCEXL's are 28*

groran

My Feedback: (76)

The wealth of information from very wise people is most definitely appreciated, thanks to all of you that responded and have answered my question, but feel free to add to the post, thanks again, Randy