Again, not a car...

[Interior:  Garden Tool Repair Shop]

"ding ding"

"Good morning sir, what can I help you with" 

      "I needs some tune up parts for a Sthil MS880"

"Chainsaw?"

   "Airplane"

RX Reven' said:

As I mentioned, each engine would be connected to the central drive shaft by a ratchet release mechanism...if an engine quits, it would just go off-line without placing drag on the system.

I took the concept to the extreme in my P&W R-2800 example, what I was specifically working on was a seven cylinder engine using Sthil MS880's (22.2 lbs. - 7.42 C.I. - 8.5 bhp) so 59.5 bhp. & 155.4 lbs. for the engines and something like 55 bhp. & 210 lbs. for the complete system...75% continuous power would yield a little north of 40 bhp.  

Interesting exercise. It would probably be lighter than that, given that you would have a common crankcase, shared crankshaft, no bars or chains, etc., but still. 

At what point does a Corvair engine start making sense?

In reply to DarkMonohue :

Homebuilders have been converting Corvair 6s almost from the beginning.

Laugh all you want about chainsaws, John Moody stuck one on his Easy Riser hang glider and created an entire genre of aviation: ultralights.

In reply to DarkMonohue :

Actually, it wouldn't have a common crank case as that would require all of the engineering, fabrication, and balancing associated with a traditional master / slave piston rod configuration:

Instead, my idea is to mount each complete engine to what I'm calling a power collator.  Obviously, this would be heavier, increase frontal area, and result in more frictional loss relative to a traditional radial engine but the engineering, fabrication, and balancing would be within reach of anyone possessing basic wrenching skills.

Basically, the design concept is to take advantage of the economy and quality you get with mass produced off the shelf engines and accept the relative inefficiency in the interest of having something that's really cool and unique.

I've done some FMEA work in an effort to convince myself that the design isn't subject to systemic failures but I feel like I'm starting to high jack this thread so I'll stop here or not  

Here's an L-5 Radial for sale - cheap. So now your new boxer is closer to paid off.

In reply to Appleseed :

I'm aware, and have spent too much time daydreaming about doing it. Flat fours don't do it for me, but flat sixes push the right buttons.