View Full Version : F4U. Starting the engine...

04-22-2005, 03:16 PM
I am looking for additional info on how the shotgun shell starting mechanisms worked.


04-22-2005, 04:28 PM
I have a dvd that shows it in a training film, just like it says, they load the shell in, close it off and it propells the engine into motion somehow, that's all I know, wish I could pass along the vid, let me know how if I can. maybe a portion of it.

04-22-2005, 04:38 PM
I was able to capture a couple of pics. How do I pass them on? e mail?

04-22-2005, 06:43 PM
http://photobucket.com/albums/v210/farber2/aaaa lets see if I got this right

04-22-2005, 06:47 PM

04-23-2005, 01:42 AM
Thanks, thefarb2. I have that video too, got it on Zeno's.

I read HERE (http://www.acepilots.com/usn_blackburn.html) they had some troubles starting the engines and I would like to know how the shotgun shell started the engine and how they solved those problems in more advanced versions of the plane.


04-23-2005, 02:31 AM
Shotgun shells were used to start certain tractors as well,maybe a source of info there.

04-23-2005, 11:33 AM
Thanks, nice pictures of Australia and... what's in the plane???

04-23-2005, 12:15 PM
To He who asked how it is done.

The Shotgun Shells weren't actual shotgun shells, but expansion gas cartridges.

In Diesel tractors (read Cat Bull Dozers) and many planes (with radial engines like the B-25,B-26, and a number of B-29's), when you inserted and latched the cartridge, you also closed off the primary intake manifold port.

With the intake manifold intake port now closed, there were any number of intake valves, or in the case of some radial engines, intake slots opened.

The Cartridge was fired into the intake manifold, the rapidly expanding gas went through to the intake valve(s), pushed down on the piston, and began to spin the engine. Very similar to an Air Starter that used an air compressor to spin up the engine. Many old jets used compressed air to spin-up the compressor turbines.

All too often the engine's electric starter did not have enough battery power to do the job, and after several failed attempts, the engine got flooded with fuel. Same with stored energy hand cranked starters.

In that case, you had to use more than 1 cartridge to get things going. The first cartridge was used to clean out the cylinders with the ingition off. Then a second was used to sipn the engine to build up oil pressure. The third cartridge then was used to fire up the engine with the Magnetos On. (Get the original 1970's version of the "Flight of the Phoenix" movie to see how this was done).

This technology is as old as the internal combustion engine itself. The Otto-Cycle 4-stroke engine is nothing more than an air compressor/air expander that converts chemical energy to rotational mechanical energy. If you forced enough air under pressure into the intake tract, you could spin the engine fast enough for the magneto-ignition system to get going on its own.

Anyone old enough to remember push-starting Fuel Dragsters?? Or pulling on the propeller of WWI aircraft to start the engine? Does the phrase "Contact" mean anything? (In aeronautical terms, it means Ignition On)


04-24-2005, 02:57 AM
Very interesting spqr1951.

Thank you.

04-24-2005, 04:50 AM
Easy http://forums.ubi.com/images/smilies/25.gif

Just press the "I" button when you are standing on the runway or the carrier deck http://forums.ubi.com/images/smilies/88.gif

04-24-2005, 07:53 AM
I key ??? You sure ???? I'll give that a try. http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

04-24-2005, 08:03 AM
Hope this helps!
It's for mighy Napier Sabre, but principe is the same.
AFAIK it was needed 400 lb-ft (540 Nm) of torque to sucessfully start the R-2800!!



04-24-2005, 03:34 PM
Thank you so much, Mosor.

04-24-2005, 04:48 PM
I remember push starting a LOT of stuff. I've "propped" a LOT of engines on planes too. Nothing bigger than a 220 Lycoming though.

04-25-2005, 04:04 PM
Thanks a lot, PE_Mosor: You have brought back a lot of memories about the Coffman Cartridge Starter system from Rolls-Royce. http://forums.ubi.com/images/smilies/88.gif

My Grandfather had a '30's rolls, and in the trunk was an enameled wooden box containing a cartridge starter set up. It clamped to the carb and would fire the engine should the starter go bad.

He never tried it, but I can only guess that explosions were common with its use. What with 1200 degree gases under pressure shooting through a carb full of gasoline.

http://forums.ubi.com/images/smilies/25.gif Where did you find those old manuals?