Bore VS Stroke = NO Effects, Size= NO ECO Effects.

[Sam147]

Been playing with the demo in sand box, all my engines are 191CI, don't see any benefit or use for anything else. Not even ECO benefits from going smaller.There is no change to Block material or engine dimensions when i change bore and stroke. Not talking about the graphics but the actual effects of this.

ECO = When i go to smaller blocks or Displacement i don't see Any better ECO. I get better Ron that can be turned into Eco but that's it. Its like the the stat should be Efficiency based on displacement and HP, Not ECO. Larger pistons suck more gas and larger combustion chambers use more gas.

Long Stroke = Making a long stroke 141 should increase Airflow/fuel rate due to the same amount of "piston displacement" and thus suction but smaller chambers. This of course only effects Carbed engines, but the effect would be nice on cheaper carbed engines. Maybe its in the form of better RON. Already getting this from smaller displacement then 191. So its hard to tell if i'm getting the effect from "suction/chamber effect" effecting the Fuel and the RON.

Short Stroke = 141 engines have there own effects by being able to burn more gas and create more power with less friction. Less metal means less weight but lower MTF. Worse RON due to piston flap but less stress on lower end parts. Less friction from metal to metal contact for better ECO and RSP.

Smaller Engine = Smaller amount of gas, Better ECO.

Short Stroke = More power less friction with better fuel system, Less weight, Less stress on lower end.

Long Stoke = Better MTF (THIS IS A MUST), Can get more out of cheap Fuel system, More weight, Better Ron.

Bore and Stroke = Engine dimensions and Weight or MTF.

Maybe its because i'm American and like everything larger. Just seems larger still uses the same amount of gas so why go small. Gonna take a better look at demo now that i have put more thought into the "bore vs stroke" thing. Gonna go build a short and long stroke 141 and compare the two, but the whole engine size thing bugs me with the ECO.

[Killrob]

Jupp, these are indeed some shortcomings of the current public version. Everything you are talking about has already fixed in the current beta build of the engine designer revamp.
What you don't seem to get (and you are NOT alone as we hear that all the time): fuel economy. The only thing you can test on an engine stand is fuel efficiency (kWh produced per unit of fuel), and what is displayed in game is the inverse of that: lower value -> more efficient. That doesn't mean that larger engines won't drink more though, they will, especially after the revamp, where fuel efficiency is mapped as a function of RPM.

In the current public build only capacity really affects power output, which is wrong of course. Apart from bore affecting RON, which is correct. In the revamp we are currently working on breathing restrictions due to small bore (at high engine speeds) are included.

I don't see your point of "more stroke -> better reliability" though... care to explain?

[Sam147]

Any Feed Back on what happens in Real life motors with "Bore Vs Stroke" would be great. Just think there should be more of a difference between the two, but i could be wrong.

But No Eco Effect with smaller displacement, I is know is wrong.
With bore and stroke, Don't See the Engine taking up any less space in the stats, or a change in MTF.

[Killrob]

Basically it is
Bore/Stroke > 1 = good at breathing, revving and smoother, but needs higher RON, is more susceptible to valve float (larger heavier valves) and a bit heavier. Over-square engines can potentially make more power.
Bore/Stroke < 1 = good eco through higher possible compression, lower RON, less susceptible to vale float, lighter, but less smooth and doesn't rev as high.

This is probably not everything, but you get the picture. Most of those things are NOT in the current public version yet, but fully working in the revamp already.

[Sam147]

Ok, on the LESS Bore = BETTER MTF thing, gonna have to give you the Alabama answer, lol.

"yeap yeap, well ya see down here we takes these chevy V8s and bore um out till there aint hardly no metal left in the cylinder side walls. Well that aint none too good friend being as it makes the engine over heat due to less metal to absorb the heat. Less metal also means your more likely to get a cracked block due to stress, or a piece of dirt or something can wear a hole right into the water jacket. Now you goes and Asks anyone who drag races or does any dirt track racing about OVER-Boring an engine. Usually not an issue we just go out back and get another Chevy V8 off the junk pile, when it blows."

Hope you got a chuckle from that, every 4th kid at my high school had a race car it seemed.

We are talking about the same size block here, so its not More Stroke but Less Bore giving you Thicker metal and/or water jacket. Thicker Metal Can handle more Stress and Heat so better MTF.

Wanna make that V8 or V6 thing from autoshop in high school. It had an aluminum shell for a block with steel sleeves for cylinders. The whole thing was hollow to the point to where you could kick it across the floor, it was all water jacket. Not sure if it came like that or the teacher just modded it, to that point. Think he did because there's no way a water pump would work with it.

[Killrob]

Hehe xD yes, you are of course right about worse MTTF for upbored engines! I already forgot that we do have fixed block sizes in the current build, and in there it should of course be the way you describe. In the revamp we have free-scaling for the engine blocks, so there is no upboring the engine and thus MTTF is not affected much either by going up in bore - the block just gets bigger and heavier.

[Sam147]

Basically it is
Bore/Stroke > 1 = good at breathing, revving and smoother, but needs higher RON, is more susceptible to valve float (larger heavier valves) and a bit heavier. Over-square engines can potentially make more power.
Bore/Stroke < 1 = good eco through higher possible compression, lower RON, less susceptible to vale float, lighter, but less smooth and doesn't rev as high.

This is probably not everything, but you get the picture. Most of those things are NOT in the current public version yet, but fully working in the revamp already.

Large Bore/Short Stroke = Well, with a larger combustion chamber(due to Bore) your gonna have more stress on you Piston Rods because your trying to compress a larger amount of fuel. Its like a larger powder keg, Not sure how this effects the RON. Also there's piston flap which comes into play, again not sure about effects on RPMS Compression ratios ECT. But you got better ECO due to less Friction. You don't have piston rings sliding all the way up and down your cylinders like in a long Stroke or whats called a Stroker engine.

Stroker/Small Bore = Most motorcycles and weed-eaters are High RPM Strokers. Your Compressing less Fuel but you have a longer piston rod which is more likely to break due to length. They kinda factor each other out in terms of piston rods, its the crank you gotta worry about in a stroker i guess, that and your over stressed bearings. Plus extra weight from longer rods.

[Sam147]

Hehe xD yes, you are of course right about worse MTTF for upbored engines! I already forgot that we do have fixed block sizes in the current build, and in there it should of course be the way you describe. In the revamp we have free-scaling for the engine blocks, so there is no upboring the engine and thus MTTF is not affected much either by going up in bore - the block just gets bigger and heavier.

Need an option later for block thickness, so I can make an unbreakable truck engine.

Also there are different grades of Steel/aluminum to play with, I hear German Steel is pretty Strong. It maybe, I got an 1991 190E benz the head should have cracked/warped on it already, after it over-heating 5 times.

[funkmachine]

yes there is the old route of lowering costs by useing lower quality metals and stuff.