Petrol engine ignition unit

[Graham Crossley]

I am fitting an MVVS petrol engine for the first time in an Xtra Wot and there is an extra 'lump' to mount somewhere ie the ignition unit. If fitting it inside the fuselage then a large hole(s) would have to be drilled in the firewall to get the plug connector and timing sensor through. I have fiddled around with this and the best place seems to be to have it mounted on an aluminium plate which is fastened under the side mounted engine.  Does anyone in the know have an opinion as to wether fitting the ignition unit that close to the engine is ok?

 

Thanks

 

Graham Crossley

[Wingman]

Well, generally, due to the pulsing high votage electricity involved, you want to keep the ignition system as close to the engine and as far away from the receiver as possible but you don't want to be mounting the ignition 'brick' directly to the engine metalwork as the vibration and heat transfer will damage it. The ignition unit of my Zenoah is mounted on the woodwork of the side of the engine bearer 'box' of the Maule and the  HT lead is coiled up beneath and behind the engine (inverted fit). This means there is only a very small hole through the firewall to the ignition unit battery which, of course, needs to be kept well away from the engine heat. Watch out for long metal throttle runs and metal servo horns causing interference oh and 2.4 is the way to go if you don't already.   

[Graham Crossley]

Thanks for the info' Wingman. I do have 2.4 radio and the plate with the ignition brick on to be screwed to the firewall so hopefully everything will be ok.