Hi Azarras,

I've gotten back into this hobby over the last 8-10 months after a break of 25+ years so Iam not the expert on this issue by any means. Idon't recall there being any/many gas engineswhen I first started flying RC back in the early/mid '80's. The equipment certainly has changed as has the quality, size, and complexity of aircraft being offered and certainly the skill level of the people this hobby has by the short hairs, me included... not skill level.....the other 'cause I'm hooked!

With that said, my opinion on your question is this-I think the mounting of any power plant is dependant upon the amount of room in the cowl and how much or little the builder/assembler wishes to cut the cowl to get the engine to fit within the cowl's confines.

I don't know that it really matters with most engines if the cylinder head is up or down, just the room allotted to install it and the cowl. I've read here on this forum that folks have tilted the engine head to just about any point in an effort to make it fit. In addition, engine cooling comes into play as do a myriad of other points such as throttle,choke, ignition, and fuel linerouting.

If I'm mistaken in my thought process, something my wife often tells me happens with great regularity,I'm VERY LUCKYto have married someone who is always right and more than willing to point out to me when I'm mistaken. THANKSDEAR!!!!!!!!!, I'm certain someone will chime in with the correct answer and will most likely make much better sense that I have here.

BTW...not a dumb question at all. There's a steep learing curve in this hobby and, as you probably know, the only dumb question is the one not asked.

It takes ALOTof research to find answers when all one has are the internet forums to glean information from. As of yet, I haven't found any books or clearly written articles that teach a newbie (ME) the step-by-step process of building or assembling either glow or gas aircraft and all the associated electronic and mechanical equipment needed. Most all I've learned has been by research and asking questions on the boards. A LOTof really good people have helped me progress to the point I'm at now and I've said"Thank You" many many times.

Best Regards & Good Luck!!