I tried searching google for that info and depending on the sources, they either say that both get similar finishes, or that aluminium gets a slightly better surface finish.
At least that’s what I found for sand casting, but AFAIK it will also depend heavily on the alloy used and how viscous it is when melted.
Although from what I heard, you actually want your ports to have a slightly rough surface so the airflow doesn’t stick to them, so I don’t know if the surface finish really makes that much of a difference.
On the topic of increasing bore and stroke down the line instead of only decreasing:
The Chrysler SOHC V6 started out as a 3.5L with 96mm bore and 81mm stroke. A smaller, 3.2L, version was later introduced with a smaller bore (92mm) but the same stroke, as has been mentioned here, and this idea makes sense. However, a decade or so after the 3.5L’s introduction, it was expanded to 4.0L, with the same 96mm bore but with a 91mm stroke. So while I agree with the points about increasing the bore as a not-gonna-happen sorta thing, increasing the stroke shouldn’t necessarily be out of the question. There’s been a few people who’ve taken the 3.5L blocks and stroked them to 4.0L without extensive modifications as well.
Yes, but the problem is if you let people make an engine bigger then you can exploit the system by designing a 3.5 and then boring/stroking it to 4.0, then you’d have an engine that’d be lighter and smaller than an engine designed as a 4.0, which is a bit silly.
It’s simple enough with the current system, the bore and stroke on the first tab is setting the MAXIMUM possible bore and stroke that block could possibly fit, then the varient bore and stroke is setting how much of that available space you actually choose to use.
[quote=“Daffyflyer”]Yes, but the problem is if you let people make an engine bigger then you can exploit the system by designing a 3.5 and then boring/stroking it to 4.0, then you’d have an engine that’d be lighter and smaller than an engine designed as a 4.0, which is a bit silly.
It’s simple enough with the current system, the bore and stroke on the first tab is setting the MAXIMUM possible bore and stroke that block could possibly fit, then the varient bore and stroke is setting how much of that available space you actually choose to use.[/quote]
Ah, I see what you’re saying. Balance is something that I tend to overlook a lot
The best match between Automation’s engine family system and a real-life engine family is probably the Honda K engine. Every single one is an all-aluminum 16-valve DOHC with VVL, with engine capacities ranging from 2.0 to 2.4 litres; the differences are mostly tune, cam profiles*, and MPFI vs DI. Even redlines range from 6500-7500 RPM.
With that said the 2.0 litre K block has a shorter deck height than the 2.3 and 2.4 litre block, so one could argue that they’re actually two different engine families as far as Automation is concerned.
[size=85]*Honda uses two entirely different VVT/VVL systems for performance and economy K engines, although both are marketed as i-VTEC.[/size]
The primary benefit of a rough intake port is an improved rate of fuel evaporation off the intake walls.
[quote=“Sayonara”]My two cents about this engine family affair:
The best match between Automation’s engine family system and a real-life engine family is probably the Honda K engine. Every single one is an all-aluminum 16-valve DOHC with VVL, with engine capacities ranging from 2.0 to 2.4 litres; the differences are mostly tune, cam profiles*, and MPFI vs DI. Even redlines range from 6500-7500 RPM.
With that said the 2.0 litre K block has a shorter deck height than the 2.3 and 2.4 litre block, so one could argue that they’re actually two different engine families as far as Automation is concerned.
[/quote]
That’s probably about right, yeah.
I think most of the LS V8 motors would be the same family too, as would the Honda B18 and B16. Every flavor of Nissan SR would be the same family too I think… (I’m pretty sure they’re all the same external size?)
If the family started in the middle rather than the largest possible couldn’t you apply a reliability bonus or penalty due to the wall thickness between the bore holes? So you could build a light weight, overbored engine but it would suffer due to thin walled design, and contrastly a thick walled under bored version would be heavier but allow better oil and coolant passages and gsin reliability. You could sink quality points into the bottom end to counter the thined walled penalty which would probably be for higher end motors like the LS7, it has very thin walls but due to its higher quality design is quite reliable untill you start to boost it which is why the LS9 has a smaller bore for a tougher block to handle the supercharger.
The same can go gor stroke length ad a large increase will lead to ovaling the cylinder due to the angle of the taller crankshaft.
I really don’t see why we’d want to have a complicated system like that though? What is the disadvantage to specifying the largest capacity that will fit in the block when you design the engine?
Gamer:
“Hmm, I want to build an engine in three different displacements. I’ll start with the middle one first, because it’s the average, and it makes a lot of sense to start with the average. I can just make it smaller and bigger to suit the car it goes into.”
Developer:
“We’ll get the player to build the biggest engine first, because that’s kind of how it works in real life. You can’t magically stretch a block, so it makes sense to specify the largest engine first.”
Gamer:
“Wait, why can’t I stroke my 2.0L into a 2.2L? Honda did it. This game is stupid.”
So basically “biggest engine first” isn’t intuitive to a lot of people. Said people then perceive the system as something they have to work around rather than something to work with, which creates frustration.
Gamer:
“Hmm, I want to build an engine in three different displacements. I’ll start with the middle one first, because it’s the average, and it makes a lot of sense to start with the average. I can just make it smaller and bigger to suit the car it goes into.”
Developer:
“We’ll get the player to build the biggest engine first, because that’s kind of how it works in real life. You can’t magically stretch a block, so it makes sense to specify the largest engine first.”
Gamer:
“Wait, why can’t I stroke my 2.0L into a 2.2L? Honda did it. This game is stupid.”
So basically “biggest engine first” isn’t intuitive to a lot of people. Said people then perceive the system as something they have to work around rather than something to work with, which creates frustration.[/quote]
I totally agree with this. I myself start off with the middle ones most of the times, and while I am at it tink, Oh Snap! I need to make the largest one first!
I noticed that if when you are designing the engine family you can set the initial bore and stroke then head to the variant page and set the sliders to minimum then head back to the family page and it will show the minimum displacement as you adjust the bore and stroke further.
[quote=“Sayonara”]Gamer:
“Wait, why can’t I stroke my 2.0L into a 2.2L? Honda did it. This game is stupid.”
So basically “biggest engine first” isn’t intuitive to a lot of people. Said people then perceive the system as something they have to work around rather than something to work with, which creates frustration.[/quote]
This is all so pointless. In the future all my engines will start out to be 120x120mm. I dont understand at all the need for another “feature” that increases work. As if the constant “could not fit engine” isn’t annoying enough.
As you keep building a engine family I’d imagine you’d be able to open up new tech and can begin decreasing engine size as better technology becomes available. My 5.0 liter 1980’s 4 barrel carb v8 can become a lighter weight 4.0 liter fuel injected while still keeping the same power and time tested family reliability. I can see this system working quite well once we all figure out how to use it.
Which will make all your engines very large for their bore and stroke.
No you probably don’t understand the need for this feature, but it’s a pretty important in the context of how the finished game will work. Lot of the design decisions we’re making now are made with things further down the road in mind. And they can sometimes temporarily make the current game worse. Sorry.
We’ll certainly be improving things to make it more clear what range of available capacities a given family size can fit though. That absolutely needs improvement.
Devil’s advocate - the current system when building, when you’re setting max bore and stroke, does say “minimum capacity” already on the tooltip. I don’t think it will take much more work to make it clearer. Maybe making the main UI itself have a max/min figure side by side or stacked where the existing displacement indicator is.
There’s been a few people who’ve taken the 3.5L blocks and stroked them to 4.0L without extensive modifications as well.
