Warbird Information Exchange

I have been working with a mechanical engineer who creates prototype engines. We have discussed the possibility of creating inverted V-12 engines similar to the DB600 series. The engine instead of using a cast block could be created by fabricating the engine case out of box structure with side structural panels similar to what is used in the shipbuilding industry for cargo ships. The lubricating system would have to be dry sump and pressurized.
Cylinder assembly/ heads would bolt to the bottom, these could be reworked 1710 or 1650-1 units reworked to allow for the inverted application. Also crank would be out of one of those type units with spray lubricating nozzles similar to the "Ney Nozzles" that are on my Bonanza.
The engine would be very labor intensive but still cheaper than trying to cast original style parts. We are going to look further into what thermal distributions would be (potential cracking issues) and weight issues that could be reduced by use of Aluminum. The hope is that modern operating technique with lower Manifold pressures / no war emergency power would mean an engine that is much less stressed.
I would welcome comments from anyone with engineering/ welding fabrication experience.
Does anyone know if something like this has been tried before?
Thanks, Robert

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All I did was press this red button here...

Less stressed, seriously.
Some Government licensing agencies will demand that if you have a ME-109 or FW or ? That is built with a 1800, 2000 or ? Horsepower engine that the engine you put in it will need to be the exact replica of the original. They don't give any leeway for substituting a lower HP new design engine for an existing airframe.
There are some places that will allow something of that nature but it'll have a bunch of restrictions on it typically. Easiest would be to build a Homebuilt Lookalike maybe scaled down a percentage to match the HP out of the motor.
Allison and Merlin Crank and Rod oiling is done through the Crank with pressure and volume. I wouldn't try to reinvent that wheel. On the Merlin there is a couple crank oil flow setups.
I'd study up the Roll Royce Heritage series on the Merlin design, testing and changes. There are various books in the series and you'll probably find some info there that is useful.
Good luck.

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Rich Palmer

Remember an Injured Youth
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#64- Stay Strong and Keep the Faith

BOOM BOOM, ROUND ROUND, PROPELLER GO

Don't Be A Dilbert!

Is this principle like the Crosley "CoBra" engine? That was the four-cylinder unit made from stampings copper-brazed together, used for APUs during the war and the first postwar Crosley cars.

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All right, Mister Dorfmann, start pullin'!
Pilot: "Flap switch works hard in down position."
Mechanic: "Flap switch checked OK. Pilot needs more P.T." - Flight report, TB-17G 42-102875 (Hobbs AAF)

The CoBra engine was a good idea, but suffered from corrosion problems in service. Very few survived. I've only seen a video of one that is operational. Probably not as much of an issue today, but I still wouldn't do that with an aircraft engine. Brazing works fine if it is done properly, but the only way to know for sure if you have a good bond is to destructively test it. You also need a lot of fixturing to control warpage.

I like the thought of building a modular engine machined from plate, but engine manufacturers spend tens of thousands of hours designing and testing to get a new car engine right, and this is for a plane.

Instead of reinventing the wheel, why not just modify an Allison to run inverted?

Ranger made an inverted V-12 for the SOC Seamew, but the Navy couldn't seem to get the reliability issues (mostly cooling) down.

This gentleman apparently figured out the cooling problems. I wish I could remember the specifics of how he figured it out, but this is the video of him firing it up:

http://www.youtube.com/watch?v=XTapiJ_LQU0