TechTom

My Feedback: (1)

Hello guys, Got a question. I am building my first gas plane. I have come to the realization that I am not sure how or where I want to mount the ignition on this bird. Its a DA50R with the electronic ign. The plug wire is only so long for one thing. If I mount this behind the firewall do I drill access large enough for plug wire boot and then use a grommet? I am just not sure. Feel free to suggest anything. Thanks!

flyinrazrback

My Feedback: (69)

do you have room to mount it on the outside of the motor box somewhere? I prefer mounting mine outside the box to insure they get airflow to keep cool

TechTom

My Feedback: (1)

Hey Flyinrzrback, I am looking into that as an option also. I am putting this in a GP Christen Eagle. If I can find a way to mount this where the cowl mounting ring isn't in the way I may do just that.

flyinrazrback

My Feedback: (69)

No matter where you mount it, its good for it to get air flow, also when you mount it, try to mount it where air can get under it as well, just 1/8" clearance is enough. Even DA ignitions fail, so rule out the overheating probability right from the start.

TechTom

My Feedback: (1)

Thanks for the input. When I get the engine back on it I will try different configurations and see what my options are. I am connecting linkages now so that should be fairly soon.

TechTom

My Feedback: (1)

OK, I have an idea of where I want this thing to go. Got any ideas of how I want to mount it? I think I can mount it in the engine compartment but how do I air to flow on all sides?

flyinrazrback

My Feedback: (69)

What I do is find some 1/8" ply or such, and make little squares to mount it on allowing air to go under it, cant remember if the da ignition has the little u shaped recessions allowing for a servo grommet, but if it does, thats what I use, then use screws to hold it down, all sides do not have to have air flow, but the general unit needs to have some as well as space underneath it, are you mounting it on the motor box on the outside? also if you dont want to use screws zip ties or velcro works too.

GeraldRosebery

My Feedback: (14)

I am curious as to why you want to use a location right next to ahot engine to keep the ignition cool. It uses about 250 ma (1/4 amp) at 4.8V (say 5V) for a power dissipation of 1.5 watts in a device that has a mass of 3 ounces in a heavy duty aluminum (heat sink) box. None of my ignitions have ever been above ambient. If you want to keep it cool, keep it away from a hot engine and exhaust.

flyinrazrback

My Feedback: (69)

I dont recall mentioning mounting it on the bottom of the box by the muffler, I always mount mine on the top of the motor box. I have done this with DA and 3W ignition for several years and never had a single failure of any ignition that I have had.

TechTom

My Feedback: (1)

Ok...I have ended up with the ign. mounted on the side of the engine box. The spark plug wire was too short for me to feasibly mount it in the fuselage. It is just too enclosed to get my hands in there. The ign. is over an inch away from the exhaust. I sure hope this is adequate

02ViperTwin

I don't know the specific differences between DA's and C.H. Ignitions' Electronic Ignition Modules, but FWIW C.H. Ignitions seems to be more concerned about vibration than cooling. Here's an excerpt from the instructions that came with the C.H. Ignitions unit packed with my Taurus TS-52...

1. Wrap the ignition module in foam, just as you do a receiver. We usually put the module in a plastic baggie before wrapping in foam. Protect from vibration. I have been asked if it is OK to mount the ignition module on the front of the firewall ... beside or below the engine. This is fine but you do need to protect the module from fuel and vibration. I put a couple of cup hooks in the firewall and then place a 1/2" thick piece of foam under the module. The unit is held to the firewall by rubber bands ... simple but effective. Our big engines shake a lot. You MUST protect, the module. Please don’t use Super Glue or RTV to glue the module solid to the airframe.

Hope this helps.

GeraldRosebery

My Feedback: (14)

Yes, that's OK, I am not challenging where you want to put your ignition for convenience or balance purposes. What I meant was that there is no need to arrange for cooling of ignitions. It's just not a problem.