Alrightee, heres the engine stuff, I've made an example for the first engine in the game which you can either invent or acquire from third parties, Victoria(the game renames it to E1 once you acquire it)
First take a look at its stats ingame:
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Now to the h4><><0|2 p4|2+.
In the game data files(the relevant file is called 'game.stc' and is located in the GFX folder of motor city) or in your savegame ('game#.gam' where # is the ordinal number of your savegame slot, also located in the GFX folder) this engine looks like this:
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Now to decipher what is what:
1 - code of the image used for the engine sheet
2 - ordinal number of engine
3 - length of engine name
4 - engine name
5 - year made available (6807 -> 0768 -> 7x256+6x16+8x1 = 1896, for those unfamiliar with hexadecimal base, if such exist here
)
6 - Engine HP (0500 -> 5HP)
7 - RPM (8002 -> 640RPM)
8 - Steel used for production (0A->10 steel per unit when producing part)
9 - Number of cylinders (01->1 Cylinder)
10 - Weight (B300-> 179kg Engine Weight)
11 - Cubic capacity (540B -> 2900 ccm)
12 - Engine price (E7 -> 231,- one is game default, the other is your factory price)
13 - Sales and consumption stats (irrelevant for moding, just dont let these fields confuse you when fixing ongoing games)
14 - Production time (the smaller this value is the faster the component is produced(more units per month), and vice versa)
15 - Research time (FFFF means the component is not researched, 0000 means it is known, anything inbetween indicates ongoing research)
Other than that... the game database currently contains 25 engines:
1 Cylinder, 5HP - Victoria(5HP,1896), Daimler(4HP,1894), Decauville 4(4HP,1898), Fiat 4(4HP,1899)
1 Cylinder, 10HP - Cadillac 7(7HP,1903), Renault 10(10HP,1903), OTAV(6HP,1905)
2 Cylinder, 10HP - Lanchester(8HP,1897), Renault 6(6HP,1901), Fiat 8(10HP,1901), Ford 8(8HP,1903), Renault 9CV(9HP,1906)
2 Cylinder 15HP - Renault 14(14HP,1901), Opel 12(12HP,1902)
2 Cylinder 25HP - Buick 22(22HP, 1907)
3 Cylinder 15HP - Clyde 14(14HP,1906)
4 Cylinder 20HP - Fiat 16(16HP,1902), Fiat 20(20HP, 1906), Gaggenau(20HP, 1907)
4 Cylinder 25HP - Peerless 24(24HP,1904), Rolls-Royce 25(25HP,1905), Fiat 24(24HP,1907)
6 Cylinder 25HP - Albion A6(24HP, 1906)
6 Cylinder 40HP - Rolls-Royce 36(36HP, 1907)
6 Cylinder 50HP - Rolls-Royce 48(48HP, 1907)
And there are another 135 slots empty that could be modded to add new engines.
As much as I've figured it out, the game lets you research only one engine from a category, thus, 14 out of 25 engines are redundant and you can actually use only 11 engines, so the current engine research tree looks like this:
1896 - Research 1 Cylinder 5HP
1897 - Research 2 Cylinder 10HP(or wait to 1901 for best model)
1901 - Research 2 Cylinder 15HP
1902 - Research 4 Cylinder 20HP(or wait to 1906 for best model)
1903 - Research 1 Cylinder 10HP
1904 - Research 4 Cylinder 25HP(or wait to 1905 for best model)
1906 - Research 3 Cylinder 15HP, 6 Cylinder 25HP
1907 - Research 2 Cylinder 25HP, 6 Cylinder 40HP, 6 Cylinder 50HP