will it be taken into account that for instance pushrod engine will have a much lower center of gravity then DOHC 4v/cyl engine?
if not, please take it into consideration
Yes, this will be taken into consideration. That’s one of the advantages of Boxer engines for instance. 
How about slant 6 motors? Like BMW’s.
Those will not be in, no. Too much trouble (in implementation) for too little benefit. If we see an elegant, easy way of getting that in, we will. But probably won’t happen.
What sort of trouble do they pose?
How to make this kind of mechanic intuitive, how to adapt the piping dynamically, how to calculate dimensions correctly as a function of rotation angle.
Ahh, so its an issue with the way the game is designed, rather than an actual problem with the way the engine works. Makes sense, it sucks, but makes sense.
the engine works the same as a regular inline engine, i can think of at least 3 more slant engines btw
and tbh i don’t see the point of implementing that into the game as it wouldn’t make so much difference imho
The SAAB 99/900 had a very slanted engine, 45 deg, but that was because the gearbox was under the engine. The top of the gearbox is the same as the oilpan.
Made for a very compact engine unit, only the sprockets for the 3 chains from the clutch to the gearbox stuck out.
It may also have been a start for a v-8. Lotus designed it, and used the same engine block in the Esprit, which later got a v-8. 