Potez 12Dc engine information

[fastmongrel]

I am building a 1/72 scale model of the French Arsenal VG33 fighter. I am doing some online research and I have come across several mentions that the prototype known as the VG30 was designed to use the Potez 12Dc engine. The engine had problems and was swapped for a Hispano 12y.

I have googled this engine but there seems to be nothing written about it. I know Potez were working on air-cooled inverted engines before ww2 so I am guessing the 12Dc was an air-cooled inverted V12.

Has anyone got any information or photos of the engine maybe something is written in French. I would like to build the VG30 prototype with the originally specified engine.

 

[kmccutcheon]

I am building a 1/72 scale model of the French Arsenal VG33 fighter. I am doing some online research and I have come across several mentions that the prototype known as the VG30 was designed to use the Potez 12Dc engine. The engine had problems and was swapped for a Hispano 12y.

I have googled this engine but there seems to be nothing written about it. I know Potez were working on air-cooled inverted engines before ww2 so I am guessing the 12Dc was an air-cooled inverted V12.

Has anyone got any information or photos of the engine maybe something is written in French. I would like to build the VG30 prototype with the originally specified engine.

Nothing on the 12Dc, but this on the 12D...

 

[MiTasol]

Interesting engine. A little bigger than the Pratt 985 with about the same power. It must have been a very light fighter to have any performance.

 

[fastmongrel]

Thanks for the information I have looked for anything about Potez engines and not seen that.

That can't have been powerful enough for a 5,000 pound aircraft to do 330 mph it must be a different smaller but similar engine.

Does anyone know how to do a search for French language information on Google I am a bit of a dunce when it comes to the interwebs. I don't speak French but I know enough to see the correct information.

 

[brianwnz]

Try searching on the link below for a range of French aircraft (amongst others) magazines - downloads are free and I've had a lot of good information from it.

Gallica

I found the Potez 12 D searching for "Potez Type 12 D" fairly easily - see how you go!

 

[fastmongrel]

Try searching on the link below for a range of French aircraft (amongst others) magazines - downloads are free and I've had a lot of good information from it.

Gallica

I found the Potez 12 D searching for "Potez Type 12 D" fairly easily - see how you go!

I found a picture the 12D but no mention of the 12DC. Perhaps it was only a paper engine

 

[jschreiber]

I found a picture the 12D but no mention of the 12DC. Perhaps it was only a paper engine

Hello
The only reference to the Potez 12Dc I found is in the "Moteurs à pistons aéronautiques français" (Bodemer et Laugier, Docavia, Editions Larivière, 1987). It was a 12D with supercharger, 610 HP, intended to be build for the Arsenal VG30 by the Lorraine engine company, at this time owned by Henry Potez and Marcel Bloch.
Have a nice day

 

[MiTasol]

Too little is known of this engine and maybe some of our newer French and French speaking members are able to expand our collective knowledge.

F Frog comes to mind and he may well know other new members who could help

fastmongrel may now have more to add as well.

 

[ThomasP]

If it is the same engine, it may be better known under the designation Potez 12D.30. This was a horizontally opposed 12-cylinder with a reduction gear case suitable for mounting a cannon above the engine firing through the propeller shaft (ie a motor cannon). The supercharger was mounted on the bottom of the crank case.

The 12Dc was (I think) a Lorraine-Dietrich designed V12-cylinder from the late-teens or early-1920s. I do not think the design would have allowed a motor cannon arrangement, and as far as I know it never had a supercharger or exceeded about 400 cv

There may be some confusion as Potez and Lorraine-Dietrich became related at some point in the early-1930s.

 

[VERSUCH]

This might float your boat, from the HathiTrust.

Link.https://babel.hathitrust.org/cgi/pt?id=mdp.39015006075827&seq=165&view=1up

Cheers

 

[ThomasP]

I found references in the Journal of the Aeronautical Sciences from Feb'37 - to a Potez-Lorraine 12D, or Lorraine-Potez 12D, or just Lorraine 12D - all referring to the same 12D flat/horizontally-opposed engine of 475 HP. One of the references mentioned the engine had been displayed at the "French Aviation Show" in 1936.

 

[Frog]

Enclosed a copy of the page 217 of the above mentioned book " Moteurs à Pistons Aéronautiques français" by Alfred Bodemer & Robert Laugier, Docavia series, Editions Larivière, 1987.

There is a small caption (1) under the picture of the Lorraine-Potez 12 D engine that translates as: " this new cannon-engine ought to be also manufactured by SNCM-Lorraine under the designation Lorraine-Potez 12 D to equip the VG-30 (Potez 12 Dc - 610 ch)."

Odd are strong that the " c " was for a cannon engine variant of the engine.

 

[brianwnz]

Enclosed a copy of the page 217 of the above mentioned book " Moteurs à Pistons Aéronautiques français" by Alfred Bodemer & Robert Laugier, Docavia series, Editions Larivière, 1987.

There is a small caption (1) under the picture of the Lorraine-Potez 12 D engine that translates as: " this new cannon-engine ought to be also manufactured by SNCM-Lorraine under the designation Lorraine-Potez 12 D to equip the VG-30 (Potez 12 Dc - 610 ch)."

Odd are strong that the " c " was for a cannon engine variant of the engine.

View attachment 822732

Thanks for the book tip - I've found one on Abebooks and spent a little more of my daughters' inheritance

 

[MiTasol]

There is a small caption (1) under the picture of the Lorraine-Potez 12 D engine that translates as: " this new cannon-engine ought to be also manufactured by SNCM-Lorraine under the designation Lorraine-Potez 12 D to equip the VG-30 (Potez 12 Dc - 610 ch)."

Odd are strong that the " c " was for a cannon engine variant of the engine.

View attachment 822732

I agree with your conclusion but it is a pity that book has a Salmson 9AB with the Lorraine-Potez 12 D caption.

Thank you for the details though.

 

[Frog]

I agree with your conclusion but it is a pity that book has a Salmson 9AB with the Lorraine-Potez 12 D caption.

Thank you for the details though.

This page was the end of the part on the Lorraine engines and the begining of the Salmson engines part.

As during publishing special captions are placed at the page bottom, this one seemed to be a description of the engine, while it was in fact related to the Lorraine-Potez : notice the (1) on the fifth last line of the article after 12 D.

The engine is correctly described on the picture's left as a Salmson 9 Ab.

 

[Simon Thomas]

From Flight, November 26, 1936:
"Under Potez licence, Lorraine build a 12-cylinder horizontally opposed air-cooled engine with an output of 475 h.p. at 2,500 r.p.m. at 9,840ft. Each cylinder is separate and has two pushrods on the underside. The exhaust ports are square and finned. The centrifugal supercharger is situated horizontally underneath and the carburetter is in front with forward-facing air intake. At the back a "T" joint branches out to the two induction pipes which have an inter-expansion chamber."

From L'Année Aéronautique 36-37: