[FIXED]Single Cylinder Engines OP

[freeman2344]

Single-Cylinder engines are far too good right now. They are extremely cheap and can generate extreme amounts of HP given maximum displacement.

An 8L single can get up to 150HP at 450Nm for very little money. Stick a supercharger on top when that becomes available and this engine easily reaches 200HP, propelling a car beyond 200km/h and acheiving a preposterous 147mpg in 1906...given the miniscule investment necessary, single cylinders are therefore quite OP in the current build. In fact, there is little reason to build any other engines!

[Eric.B]

Agreed 100%

It certainly needs some adjustments...

[Frankschtaldt]

Single cylinder engines have always been OP (we'll at least they were in the last build). In fact, I would argue that the game presents engines in reverse, meaning that the more cylinders they have the more nerfed they get, I've posted about this before. I get the feeling that this problem has been alleviated somewhat in 1.12 but it's definitely still there.
What has made the problem so glaring now is the increased volume limit which makes it possible to make much larger and more powerful single cylinder engines.
I don't think the volume limit needs to be reduced, the equations need to be tweeked so that a single cylinder is hampered by it's need for a massive flywheel and multi cylinder engines are not. Also, the stroke of an engine should play a greater role in limiting RPM, this alone would greatly reduce the viability of huge single cylinder engines. Lastly, the number of cylinders should have no effect on MPG, this should be based mostly around power output, total volume and RPM along with some design choices with a special penalty to single to represent that massive flywheel I keep talking about.

[shaunisradd]

Wouldn't the number of cylinders be a factor in MPG?

Miles traveled divided by consumption of fuel?
When looking at an engine itself its power output can be applied to the weight of the vehicle and then take into account wind resistance and you'll have a rough estimate of how many miles you can go. If you then calculate how much power an engine can output (per cylinder then take into account a loss of compounding power as more cylinders are added) you will have to multiply the amount of fuel needed per cylinder.

Just my thoughts.

[Frankschtaldt]

The number of cylinders will indirectly effect MPG because it will effect efficiency. But a 4L 4 cylinder won't use 4 times the fuel as a 4L single cylinder which is pretty close to what happens in the game now.
The 4L 4 cylinder would probably use a little more fuel than the 4L single because it should be able to rev a lot harder but on the flip side should be considerably more efficient and better balanced and as such would be losing a lot less power to bad design.

Fuel usage is directly related to total engine displacement, rpm and efficiency if design. The number of cylinders used has an effect on these and so it has an indirect effect but it is not in it self directly involved in an engines mpg or power output or anything else for that matter, except for cost.

[shaunisradd]

Saying number of cylinders does not effect power but does effect efficiency is a very round about way of saying number of cylinders effects power....

I mean.. the side of a die is a square so its not a rectangle... but its indirectly a rectangle because it is a square... and stuff.

But back on MPG.. Displacement will effect MPG. Number of cylinders will effect displacement (In a rather large way) so... It kindof has a lot to do with MPG.

Compounding loss of MPG based on number of cylinders would, i agree, be a bad way of doing it. But they effect displacement so the wagons are circled.

[Frankschtaldt]

Saying number of cylinders does not effect power but does effect efficiency is a very round about way of saying number of cylinders effects power....

I mean.. the side of a die is a square so its not a rectangle... but its indirectly a rectangle because it is a square... and stuff.

But back on MPG.. Displacement will effect MPG. Number of cylinders will effect displacement (In a rather large way) so... It kindof has a lot to do with MPG.

Compounding loss of MPG based on number of cylinders would, i agree, be a bad way of doing it. But they effect displacement so the wagons are circled.

Firstly, try reading what I actually said.
We are approaching the question from different angles and if you can't understand my last post I really can't see any way I can say in a way that you will understand.

[Arakash]

I really dont have the technical knowledge to enter into most of this discussion, but i thought id raise a relevant historical point.
At the point in time we are usually talking about (1900) single cylinders had been around the longest(of the types available in gearcity) and i assume they were not only fairly well understood, but that engineers at the time had a lot of experience with them.
I agree that, judging by the stats on Single Cylinder engines you posted, they are OP.
When that is being fixed/improved, i think we need to keep in mind that it would be entirely plausible and realistic for them to be one of the best, if not the best choice in early games.

So in short, i dont mind them being nerfed, but dont nerf them too hard

[shaunisradd]

I suppose the point of the thread was to say they are OP. They are OP.

I'll leave the choice of how to go about calculating things to you guys. Only trying to help.

[jreg16]

This discussion brings me back to a game available on the Playstation 2 name NHRA drag racing 2. It was a very technical accurate game, and one had total control over every aspect of an engine, e.g. bore, stroke, number of cylinders, compression ratios, what kind of valve train the engine had such as solid or roller lifters... and every one of those fields had an effect on torque, horsepower, and maximum revolutions of the engine. All of these things should be considered in Gear City. I really want to see this game end up being as technically correct as it possibly can be.

---

On the topic of the number of cylinders having an effect on engine performance... The number of cylinders is independent of displacement. Displacement and volumetric efficiency is what determines the fuel economy (brake specific power consumption) of an engine. For any given displacement, the number of cylinders will have an effect on rotational mass (how fast the engine will rev up and down). One huge piston at 400 cubic inches, or twelve small pistons that displace 400 cubic inches. This also has a direct effect on rpm characteristics. Think about real engines. I'm American so bear with me. Take a dodge hemi engine. A 5.7 liter eight cylinder push rod engine and two valves per cylinder. Low volumetric efficiency (Junk from the dark ages). That engine averages 16 mpg, and produces around 347 horsepower. Now take a honda civic. 1.7 liters, single overhead cam and four valves per cylinder. That engine is advertised to put out 127 horsepower, and averages about 27 mpg. Lets use horsepower per liter as our proportion. 357 horsepower divided by 5.7 liters yields 60.88 horsepower per liter. The civic: 127 horsepower divided by 1.7 liters yields 74.7 horsepower per liter. The honda engine makes more horsepower with what it has to work with in displacement compared to the hemi engine, and on top of that, the honda provides around 30 percent better fuel economy under normal driving than the chrysler hemi motor. Based off that information, things like how many valves per cylinder and displacement are what determine fuel economy and power.

[Eric.B]

More changes are coming to this thread, So I will mark as PART as in partly implemented/fixed.

Changes so far:
Increased Stroke effect on RPM's
Engine Layout's now effect Bore and Stroke. This Nerfs Single Cylinder engines while not really effecting maximum displacement of larger engines.
Adjusted Stroke effect on torque.
Fuel Economy switched to based on displacement instead of cylinders. IN the future I will implement the values suggestion in another thread.
Maximum Bore and Stroke decrease slightly over time. I don't think there are too many car engines with 200mm strokes any more.


These changes need some extra scrutiny, so be sure to test them out for me. Thanks

[Eric.B]

Just to point out I have implemented a smoothness rating which makes very small engines such the single cylinders, twin cylinders, etc, effect luxury ratings of vehicles.

Keeping this thread marked, "part", for the other things in it.

[Eric.B]

And now with the changes I've made to bore and stroke, along with the exponential costs sliders have brought single cylinder engines to their knees!
1980 SOHC Supercharged Single Cylinder with 53x52mm bore/stroke and maxed everything is only putting out 46hp and 33ft-lbs of torque... It also costs $5000, which is about the same as a 15L DOHC V8 with 1070hp and 1328 ft-lbs of torque...

Maybe I nurfed em too much!

Anyhoo marking this thread as fixed now, i still have stuff to do in reliability and what have you, but for the most part everything in this thread has been covered.