[FIXED]Suggestions for better engine design

[Drake]

After reading the thread 'obsolecence" I came to a few conclusions. I was going to post there, but it because quite a large post and probably deserves its own thread.

The weight of the engine should be mainly based on its physical dimensions and layout, not on displacement.

Example: My '71 Datsun 240Z has a 2.4L straight 6 engine. However, if I were to use the longer stroke crankshaft from another version of the same engine, and shorter connecting rods(so the pistons don't hit the valves/cylinder head) I could increase the displacement to 2.7L. This is a common modification, and would not increase weight.. I could even take it a step further and bore out the cylinders and put bigger pistons in and get even higher displacements without increasing weight. Some enthusiasts and racing shops have even made 3.1 and 3.2L engines from these engines..

Or to use another example right from the factory would be the Difference between the L24 in my Datsun, and the L26 and then L28 in the 260Z and 280Z. All these engines use the same block, and aside from differences in the fuel system, would all weigh roughly the same.

Displacement should make some difference in weight, but it should be minor compared to the actual dimensions of the engine. But of course you cannot bore an engine out too far before hitting coolant passages, or just not leaving thick enough walls between the cylinder and those coolant passages without severely affecting the reliability & longevity of the engine.

The sliders in place could represent that easily though with some tweaking. For example you could make one engine with length and width sliders at maximum. You could then take that engine, increase the displacement and decrease the length and width to get the same dimensions and you would be essentially boring the engine out.. Of course reliability should go down, and more drastically the closer you get to reduce.(it seems to have no effect of reliability right now)

To continue my real world example take the difference between the L24 and L28. L24 has a 83mm bore, and 73.7mm Stroke. The L28 has a 86mm bore and 79mm stroke. Despite this, the L28 is just as reliable and long lasting as the L24.. So in game that should be a minor reduction of length and width, with minimal consequences to reliability.

I'm not sure I really like having a separate length/width either.. It can make for some strange engine with paper thin walls between the cylinders and thick outer walls..

I would also suggest adding a Bore/Stroke ratio slider. This would greatly improve engine design. More bore = larger combustion chamber, bigger valves and more air and fuel equating to more power. But longer Stroke = more torque.. In reality its a little more complex than that, but since your not going for Automation level realism what I suggest should do just fine..

While I'm on the subject of engines, my biggest complaint about this game is that there is no reason to ever use anything other than V engine. It is the most compact engine, and engine layouts don't seem to have any advantages/disadvantages between them so compact always = better.

Some engines are better balanced than others, such as Inline 6, Inline 8, V12, Flat 6 and Flat 4. Smoother engines are more suitable for luxury vehicles for obvious reasons. Of course some engines have drawbacks too.. Flat engines are quite loud, and that might put off luxury car buyers.. Flat engines also allow more aerodynamic cars(if Front engine), but the shape of the front end doesn't seem to affect what size engines fit in the car..

I could go on a bit more about the advantages/disadvantages of each particular engine, but I'll leave it for now.

Having none of these factors in the game really hurts the car design IMO. I hope these suggestions help create a more interesting and realistic game experience.

[Eric.B]

Welcome to the forums.

The weight of the engine should be mainly based on its physical dimensions and layout, not on displacement.

The length/width does effect weight, however it's not very much. You make a very good case for a change, so I'll tweak the numbers and increase its value while decreasing displacement's value.

Of course reliability should go down, and more drastically the closer you get to reduce.(it seems to have no effect of reliability right now)

Good idea, we should give a penalty/bonus to reliability based on the displacement slider.

I'm not sure I really like having a separate length/width either.. It can make for some strange engine with paper thin walls between the cylinders and thick outer walls..

Originally I had just a 'Size' slider, but people wanted more control over dimensions. I'll look into tweaking the numbers some more to prevent thin walls. If I can't make any progress, I may try a size slider and we'll see how that goes.

I would also suggest adding a Bore/Stroke ratio slider. This would greatly improve engine design. More bore = larger combustion chamber, bigger valves and more air and fuel equating to more power. But longer Stroke = more torque.. In reality its a little more complex than that, but since your not going for Automation level realism what I suggest should do just fine..

In the game now, displacement is pretty much the bore/stroke formula with bore being the displacement slider and stroke being various minor variables added together. Do you think I should ditch the displacement slider and add two separate sliders, one for bore, and the other for stroke?

While I'm on the subject of engines, my biggest complaint about this game is that there is no reason to ever use anything other than V engine. It is the most compact engine, and engine layouts don't seem to have any advantages/disadvantages between them so compact always = better.

The game does need some balancing, I plan to address this once I get all the major features finished.

Some engines are better balanced than others, such as Inline 6, Inline 8, V12, Flat 6 and Flat 4. Smoother engines are more suitable for luxury vehicles for obvious reasons. Of course some engines have drawbacks too.. Flat engines are quite loud, and that might put off luxury car buyers.. Flat engines also allow more aerodynamic cars(if Front engine), but the shape of the front end doesn't seem to affect what size engines fit in the car..

I do have comfort in my notes, but it never worked its way into the game. I'll see if I can work them in.

As for flat engines, there is no concept of height for both the engine and volume under the hood. Other than generating aerodynamic numbers,vehicle length, width, and total hight, the game has zero concept of the of the cars/models. If I had more resources this wouldn't be the case, but sadly it is.

Having none of these factors in the game really hurts the car design IMO. I hope these suggestions help create a more interesting and realistic game experience.

Well that's the point of beta . Remember I need your feedback on what would make the game better. You're the ones who will be buying it. I've already paid for my 800 copies!

Anyway thank you for the ideas, I'll see what I can work in for 1.09/1.10

[Drake]

Thanks for the reply. Sounds like your on the right track

I think a separate bore/stroke slider would help. My original idea was just to have a slider for the ratio, so you could have oversquare on one end, and Undersquare.. But whatever works for you

Another thing I have noticed in my recent game is the whole transverse engine thing.. To me it would make more sense if all engines were the same, and the transverse placement depended on a transverse gearbox.(Edit: I also noticed that transverse engines are bugged and don't switch length/width... there goes my new car design.)

Also what about adding Vee Angle? I know this would complicate the dimensions calculation in the designer, but it would be pretty awesome. You could even go as far as having a single set of camshafts for both banks of cylinders like on the Lancia V4 engines.(link: http://en.wikipedia.org/wiki/Lancia_V4_engine )

Just another thing to think about..

Thats all for now, but I'll post any other suggestions I can think of.

[Eric.B]

I'll take a look at the transverse code, that stuff was written a few years ago.

I considered adding cylinder angles when I pondered the bore/stroke idea. I'll probably pass on doing it, although it wouldn't be a bad addition if there is ever a GC2.

[Eric.B]

Alright, I've added bore and stroke sliders which effect displacement, block length, block height, torque, rpm and engine reliability. I've also went about tweaking the engine layout stats thus making them more balanced.
These changes will be included in the 1.10 release.


I did not add a reliability stat to the layouts however I believe in the future I may add a way for the stats on engine layouts to adjust based on how much research is putting into a certain design. This is not implemented yet.

V engines were grossly over power in older builds. Not so much any more.