Question on twin gas engine ignition setup
 

Hi, I am currently building a Yellow Aircraft P-38 and choose RCGF 45cc gas engines for power. I also purchased a Smart-Fly power expander with an optical ignition cut-off that I would like to use to cut power to both engines at the same time. I was planning to use two 2300 6V NiMh (no LIPOs sorry!) to power the receiver/servos and one 4400 4.8V NiMh to power both engine ignitions through a single optical cut-off. The obvious problem I see is that the heavy duty Futaba “Y” does not have the correct male/female connections to Y off of the battery to the Futaba ignition leads. Is this the best way to configure twin gas engine ignitions and if so how is the best way to do this? I do have some experience with gas – a DA-50 in an 30% Edge (no problem there) and a 14 year old Royal P-38 with twin O.S. 46AXs (no problem there either). Any help with be greatly appreciated as I am about to make my battery purchase. I was also going with 16oz tanks – is that large enough for 12 minute flights on RCGF 45cc engines?

Thanks,
Mike

RE: Question on twin gas engine ignition setup
 

your fuel consumption will be at least 3 Oz per minute

RE: Question on twin gas engine ignition setup
 

Unless you have counter rotating propellers (it can be done) I would not use a single battery to drive the ignitions to a pair of engines. You really don't want to deal with an sudden engine out on one side at a high power setting. Your only option would be to cut the throttle on the good engine.

RE: Question on twin gas engine ignition setup
 

I would still be using two seperate ignitions and it would still only be 4.8 V even if I lost an engine, right? The idea would be that I would rather lose both engines in the event of an electrical problem.

Thanks, Mike

RE: Question on twin gas engine ignition setup
 

Watched a large and beautiful P-38 with twin YS 120's (140's?) a couple weeks ago lose an engine. Hairy for the moment it took to throttle back on the remaining engine but after that use of the rudder and keeping the wings generally level permited the flyer a working engine to make the runway with. However, there is a lot of merit to losing both engines at the same. The decision about what to do bext is pretty well established.

RE: Question on twin gas engine ignition setup
 

Does anybody run two gas engines on one ignition battery and one ignition cutoff? Is it even possible or advisable?

RE: Question on twin gas engine ignition setup
 

If we leave the allure of modeling out of the equation, aviation uses twin engine planes to provide power plant redundancy and provide the ability to carry more weight. Modeling breaks away from manned aviation in trying to capture the visuals of artistic airframes, often eliminating the otherwise required redundancy factors in the process.

Your goal can most certainly be done, without much difficulty. As for advisability, it's an area only the owner can make the call on. If the set up meets the predetermined requirements, it fills the need. If you can't find Wye harnesses with the required connectors on the right ends it would be simple to make them yourself. Simply buy a connector kit and make them up. Only takes a few minutes. West Mountain Radio (ads in the model magazines) and AirWild sell extension kits, as would any decent electrical supply store