I am in the process of installing a Zenoah G26 (magneto version) in a 1/4 scale Cub and I was wondering what precautions are needed for RF protection. I have ordered servo harness extensions with RF chokes and applied aluminum "speed tape" to the firewall to block RF noise...
Also, I am looking for pix or advise on fitting this engine into a H-9 Cub cowling.

Anything else?
Thanks!

2.4 ghz is one solution.
They make optical isolators. There are may routes that RF can take back to your RX. Make sure your throttle pushrod is nyrod, and not metal from contact to contact. Put the RF filters on the throttle servo lead. The aluminum tape sounds like a good idea, and maybe people use it, but I might worry about what happens if you are flying the plane at an attitude straight toward you...Does it deflect your radio signal? Just a thought.
Right now I only have one gasser. It was flown on 72 Mhz with no problems for about a year, and then I switched over to 2.4 and (still) no problems. I will soon be flying two gassers, both on 2.4 ghz, so I'm not too concerned about interference...But I'm still not getting sloppy with it..

The G-26 I had mounted on my ultrastick gave me no RF problems at all. I only used the same precautions one would in building a glow powered plane. Always use a resistor plug and no metal on metal mechanical connections. You should have no problems with your setup.

2.4

What does simply being on a higher frequency have to do with eliminating RFI?

Yeah...although 2.4 may be less affected by RF noise, if at all, I've never liked the thought of blinding yourself to improper setup or failing parts, due to another component keeping you from noticing. Many folks still use older FM or PCM receivers to initially setup their plane and range check, engine running, to test for RF, and then move to their PCM or 2.4ghz receivers.

Because the RF noise generated by gas engines is no where close to the 2.4 ghz frequency. Therefore, it poses no realistic problems to those radios.

No need to upgrade to 2.4 simply because of a gas engine. While there's nothing wrong with 2.4, it'd be hard to use "I'm running a gas engine" as justification for that expense if you're happy with your current setup.

Simple precautions are all that are necessary. The philosophy is this: Don't "transmit" rf interference to the back of the plane with metal. Metal typically means: Ignition switch harnesses and throttle pushrods. So...

1. Mount your ingition switch up ahead of the firewall.
2. Use plastic for your throttle pushrod.
3. Philosophy: No wiring (or other metal) should "bridge the gap" across your firewall. Try for 12" separation if you can, but I've run less without issues.

I use a 9cap futaba, and have flown several gas powered airplanes without problems this way.
As with glow, avoid metal-rattling scenarios with control surfaces and the like.
Do a thorough range check, and this will instill confidence that all is well.

A spark contains an infinite number of harmonics. It does reach in the the 2.4 GHz band, just has less amplitude, but its there.
FM was better than AM when it came out, PCM was better than PPM when it came out, 2.4 is better than PCM, BUT it ain't fool proof.

Dear Nathen,
I think your question has been answered....