Ideas among other

[pyrlix]

Depends on the domestic market... after WW2 most manufactors, infact almost all, either used OHV or (D)OHC systems. The last European car with SV was the Ford Taunis 12M and that was using a slightly more powerful engine of the 1939 Taunus. I dont know where you got the "high performance" alternative to OHV from, but SV just have the advantange of being cheaper and more reliable. They have worse airflow, a horrible combustion chamber shape and thanks to that fuel mixture needs longer to combust, leading to low RPM, high fuel consumption and bad emission values.
Short: They are worse than OHV.

The game will start in 1946, although tech year goes down to 1940.

About the Individual Single Barrels: Could be an option although its not common on production cars, show me an example please.

[Kubboz]

From what I remember, the individual single barrel carbs were planned to be included in the extreme engine configurations (that is, V12s and V16s).

[Killrob]

Yeah! Looking forward to the hexadeca-carb setup!

[andris]

A vote for flatheads...

"Side Valves are Dead"
Yeah, in the 21st century, but the game starts in 1940, and SV was still well in use a decade and a half after that.
Its an higher performance alternative to OHV, because it benefits from almost unlimited compression, will never knock,
and a cheap alternative to OHC.
If side valves were a feature, it would be easier to create a early high performance engine. Side valves have their place.

I think it would be a necessary feature to have in the end.

Not entirely true, flathead engines are still being developed, built and used in lawn mowers, motorcycles, chainsaws, (ultra-light-)airplanes etc. just not cars (that I know of)...

Though I wouldn't say they "would be a necessary feature", I hope to see them listed as "to be considered" in what's in and out, since it's the only engine configuration I could think of that isn't there and had at least some relevance.
So don't get me wrong, I still would rather see wankels, two strokes and whatnot before I'll really miss flatheads...

Otherwise I completely agree whith the above.

edit: Biggest advantage is the compact design and low weight per power, and that's why they survived until nowadays, so don't just say OHV is simply better or even call SV "extinct".

[RobtheFiend]

The SV engines you mention are being built, not developed. All of them use ancient technology, and are among the worst performing engines in existence.

Lawn mowers: Briggs & Stratton, the engine has looked the same for decades.
Motorcycles: Harley Davidson SV engine, the last time something new happened to that one was 50-60 years ago.
Chainsaws: No idea.

Edit: LOW WEIGHT ??!!!?? what are you smoking? More compact than a OHV design, i'll give you that. But lower weight, no friggin way.

[andris]

http://www.d-motor.eu/nl/home-1.htm

Lightweight SV-engine for U-L-airplanes developed in 2010.
Edit:
brief for the lazy ones:
A 52kg SV-engine with 88.8hp.

The Ford Zetec-SE 1.3 DOHC (Ford Fiesta 1996) is nearly twice as heavy (92kg) and produces only 55hp. This means that SV has 2.86 times as much power-to-weight.

I'm not saying there weren't any OHVs with more power-to-weight...

They are developing a 6 cyl. scheduled to be released for mid 2015.

[RobtheFiend]

And it will not work, for long, in a car, being to fragile.

[Sayonara]

To be fair, a car engine is designed to be idiot-proof. Momentary over-revving doesn't do much to a modern car engine because the engineers have already taken that into account.

In a plane, "DO NOT EXCEED" means do not exceed under any circumstances, ever.

[andris]

Thats what rev-limiters are for. Besides SVs produce nearly max. power already in fairly low revs so one could play it safe there.

But honestly I have no idea how such a thing would fare in a car, all I tried to point out is, that they are not extinct and have certain advantages.

[RobtheFiend]

When they (SV) are watercooled, they have a very low distance from the center of the crank to the top of the head. To bad the sparkplug sticks out so far.