18-cylinder radial airplane engine cutaway - photo

**Jon** · Oct 1, 2019, 06:04 PM

18-cylinder radial airplane engine cutaway.

Fullsize image: https://diqn32j8nouaz.cloudfront.net...e_fullsize.jpg

Previously:

Radial engine assembly animation - GIF
Radial engine motorcycle - photos
Wooden radial engine - GIF

**jimfols** · Oct 2, 2019, 06:34 PM

Here's a video of a radial engine made out of wood. The guy did an excellent job of explaining how they work.
What I found especially well done is his explanation of the cam rings.
Rather long at 9:58 but well worth the money. The cam rings start at 5:15.

**IntheGroove** · Oct 2, 2019, 07:44 PM

Those are a marvel of engineering. The 36 cylinder engine was something to behold...

**Frank S** · Oct 2, 2019, 09:13 PM

Not an engine in the same class as a radial but the Sherman tank engine called the Chrysler multibank engine was also a marvel of engineering by taking 5 Chrysler flat head 6 cylinder engines then arranging them in a radial fashion around a single output shaft. Oiling was a nightmare as it had to be a dry sump. the 2 engine blocks mounted at a down angle had a tendency to trap oil in the cylinders behind the pistons. When the engine sat for periods of time the retained oil behind the pistons would seep around the rings into the combustion chamber. which could cause the engine to lock up the next time it was started. I only ever worked on 1 of those but I seem to remember an automatic compression release to vent not only the compression but allow any oil in the combustion side of the cylinders to drain away.
Jon is so good at locating these things maybe he can be persuaded to find a cut away of one of them.

**Scrounga** · Oct 3, 2019, 02:06 AM

WOW, awesome model with excellent explanation. There were some crazy smart people back in the day!

**jdurand** · Oct 3, 2019, 06:08 PM

Are the crank shafts geared to each other in that center hub so they the hub doesn't twist? Never seen that part disassembled.

**IAMSatisfied** · Oct 6, 2019, 05:28 AM

Originally Posted by Jon

18-cylinder radial airplane engine cutaway.

I wonder how many castings comprise this one engine? I can imagine how complex the pattern making process was at the foundry that cast the engine parts. Very impressive engineering.

**IAMSatisfied** · Oct 6, 2019, 05:53 AM

Originally Posted by jdurand

Are the crank shafts geared to each other in that center hub so they the hub doesn't twist? Never seen that part disassembled.

There's only one crankshaft, and the thing that prevents any twisting is called the master rod (which I believe is what you're calling the center hub). It is shown & described @ 4:37 in the wooden model video.