Moteur ABC1912

Bonjour
On me propose ce moteur. Quel est son prix.
Merci

Daniel,
Pouvez-vous publier plus de photos et le moteur a-t-il un numéro, merci Ian

Hello Daniel,
I am no expert but I'll try to share some guesses I've observed so far, hope other will correct me where I get it wrong and add more details I miss out.
I'll start by saying that the engine you have found is not a 1912 model. In that year ABC just modified a Douglas engine and didn't start production of their own motorcycle engines. They were still interested in aeroplane engines but those look completely different.

From 1913 they started producing 500cc motorcycle engines in small batches and these had the inlet port right at the front


At some point in 1914 they moved the inlet to the top but the heads where still quite squared and different from the engine you have been offered


From 1915 through the duration of the war the layout remained very much the same and not many bikes where produced


During WW1 they did however start producing 500cc and 250cc Power Units for ground (GPU) and Aviation (APU) purposes.
Some were started with a starting handle at the front

while others had a kickstarter that operated direct on the crankshaft extension (I have no pictures) and I'm thinking the engine you've found might be one of these.
These power units were discontinued once the war was over and only re-introduced in the '20s with a very different design.

I believe this engine is a 500cc as the 250 had a different layout


Apart from that, I cannot advise how much to pay for it. There are some in existence, probably one or two dozens in the world, but likely it will end up sitting on a shelf and not be used for any motorcycle purpose.
Having said that, I'd like looking at it while on a shelf bu that cannot be worth a fortune.

C'est un moteur au ralenti de 500cc, je paierais 2000 euros pour ça.

Merci beaucoup pour ce remarquable travail de recherche. Le propriétaire doit m'apporter le moteur, je pourrai faire des photos de détail et des N° pour identifier au mieux ce modèle.

Thank you very much for this remarkable research work. The owner has to bring me the engine, I will be able to make detail photos and no to identify the best this model.

Votre moteur sera probablement de 1915, si vous voulez construire une moto, je peux vous aider car je l'ai fait plusieurs fois.