Engine bay size

[VicVictory]

Don't laugh too hard. I used to own a car where you had to remove the battery to get to the driver's headlamp.
And my current minivan... you have to remove the whole front light fixture to change the bulbs.

I must have jinxed myself when saying this, because the driver's headlight bulb burned out on my minivan last week. And since these things have a tendency to eat the second bulb shortly after the first, I just spent my morning removing both fixtures and replacing both bulbs.

But back to the topic... Yes, there is definitely some tweaking to be done here. If small V8's are so vastly superior IRL to I4's, why don't we see them all over the place?

[vmo]

A big engine but very well designed can be better than a small engine but bad designed.

[HighOctaneLove]

But back to the topic... Yes, there is definitely some tweaking to be done here. If small V8's are so vastly superior IRL to I4's, why don't we see them all over the place?

Here in Queensland, Australia, the registration system is based on the number of cylinders the car engine has. This makes owning a large capacity 4 or 6 more attractive than the same sized or slightly larger 6 or 8 (or 12!).

The engine configuration friction losses are larger the more complex an engine is but not as much as you'd think...

For example, compare some different real-world engines; different configurations but all are 2L in capacity

RB20DE (HR31) 110Kw @ 6400rpm and 181Nm @ 5600rpm

KF-DE (Mazda Lantis) 107Kw and 179Nm

SR20DE (S15) 126Kw @6400rpm and 132 foot pounds

3SGE (Gen 3) 132Kw @ 7000rpm and 19.5 Kg/m

Golf V 2L FSi 110Kw

Ferrari 208 GT4 (V8!!!) 127Kw @ 7700rpm

Ferrari 208 GTB 116Kw

From this list a correlation can be drawn that when overall capacity is similar, engine technology and tune are the major factors in an engines power and torque figures, not the friction caused by the design. In my personal musings on this subject I've come to the conclusion that the size of the cylinder determines the engine characteristics. So for a given engine capacity, the engine with smaller, more numerous, cylinders will feel smoother but will have the subjective feeling of needing to be revved harder to produce meaningful acceleration.

I've personally driven a 2L Inline 6 and numerous 4 cylinders of around the 2L mark and this has broadly been my experience in real life conditions. All my data is subjective so feel free to flame me on any bits you don't like/agree with!

[Drake]

But back to the topic... Yes, there is definitely some tweaking to be done here. If small V8's are so vastly superior IRL to I4's, why don't we see them all over the place?

Here in Queensland, Australia, the registration system is based on the number of cylinders the car engine has. This makes owning a large capacity 4 or 6 more attractive than the same sized or slightly larger 6 or 8 (or 12!).

These are both good points... We have yet to see how the varying registration taxes affect our ability to sell cars..

From this list a correlation can be drawn that when overall capacity is similar, engine technology and tune are the major factors in an engines power and torque figures, not the friction caused by the design. In my personal musings on this subject I've come to the conclusion that the size of the cylinder determines the engine characteristics. So for a given engine capacity, the engine with smaller, more numerous, cylinders will feel smoother but will have the subjective feeling of needing to be revved harder to produce meaningful acceleration.

I've personally driven a 2L Inline 6 and numerous 4 cylinders of around the 2L mark and this has broadly been my experience in real life conditions. All my data is subjective so feel free to flame me on any bits you don't like/agree with!

Good points again, although I would add that some engine configurations are smoother than others.. For example a 2L I6 would likely be smoother than a 2L V8 because the Inline 6 has perfect primary and secondary mechanical balance without the use of balance shafts. I4's will always be a bit rough regardless of size because they don't have overlapping power strokes. Even with balance shafts they won't be as smooth as an I6, or V8 for that matter..

I also agree more or less that the added friction from say a 2L DOHC V8 doesn't cause it to lose power compared to simpler 2L DOHC I4, however it should affect the fuel economy more than It does in automation..

Currently the fuel economy calculations seem to be mostly based on the fuel system components, and how low you can get your RON requirement. This means that the more carbs(or more barreled) you throw on an engine the better fuel economy it gets. Later on its a little more balanced with less options on fuel injection systems but still the most fuel efficient engines always seem to be V8s...

This problem is also compounded by the fact that not only will that V8 have better fuel economy, but it will have a much better torque curve and thus the car will have a much higher tameness... What this will lead to is small V8's being the economy car engine of choice in automation.

A good comparison for fuel economy between 2 similarily powered and weight cars would be the Lancia Thema 8.32 with its 2L 32v DOHC V8 to a Saab 9000 with the 2L I4 turbo.. Both based on the same Chassis, but the V8 Thema gets a fair bit worse fuel economy. (17.5L City VS 12.3, 9.2 highway VS 9.0).. Even the later 9000 Aero with 10 more hp and 300cc's of extra displacement over the Lancia got better fuel economy.

There aren't very many other small V8 engined cars out there, so more comparisons are hard to make..

[VicVictory]

Kind of not my point, though to touch on what you just said... in game calculations may be somewhat broken for small V8's. Case in point: the TU class of the 1967 ITA competition I just finished running. EVERY engine displaced between 1996 and 1999 CI. There were I4's, I6's, and a pair of V8's. One of the V8's managed to put out 10% more horsepower than the closest inline competitor.

And their fuel economy is also pretty sick.

But the point I was trying to get at is this: you can shove a 2.0L I4 in a small engine bay, or a 4.0L V8. If, from both a power and efficiency standpoint, the V8 is that vastly superior to an inline configuration, why don't we see 3-4L V8's powering small cars? Or even a 2.5L V8

Answer: you don't, because that's not how it really works. And notice how that's borne out with the 2L engine comparisons above. The only V8 listed is an exotic.

which then comes full circle to the original point of this thread, which is:

In order to simulate the sizes of (transverse) 4-cylinder motors that you see in production over the past few decades, the engine bays need to be larger.

[HighOctaneLove]

A good comparison for fuel economy between 2 similarily powered and weight cars would be the Lancia Thema 8.32 with its 2L 32v DOHC V8 to a Saab 9000 with the 2L I4 turbo.. Both based on the same Chassis, but the V8 Thema gets a fair bit worse fuel economy. (17.5L City VS 12.3, 9.2 highway VS 9.0).. Even the later 9000 Aero with 10 more hp and 300cc's of extra displacement over the Lancia got better fuel economy.

There aren't very many other small V8 engined cars out there, so more comparisons are hard to make..

The Lancia Theta 8.32 has a 2.9L V8, not a 2L one! I looked on Wikipedia and elsewhere and there was only the 2.9L V8 listed

Comparing an apple with a different breed of apple is also a bad idea (Apples to Oranges would be 2L petrol with a 2L Diesel IMO )... A 2L NA is not equal to a 2L Turbo! So the original premise of the comparison is flawed

I agree that a 2L 4 will use less fuel at the same tune as a 2L 6 or 8 but I suspect the real issue is cheapness and engine bay size that makes the major differences in car manufacturer choices...

[Drake]

Kind of not my point [...]

But the point I was trying to get at is this: you can shove a 2.0L I4 in a small engine bay, or a 4.0L V8. If, from both a power and efficiency standpoint, the V8 is that vastly superior to an inline configuration, why don't we see 3-4L V8's powering small cars? Or even a 2.5L V8

Answer: you don't, because that's not how it really works. And notice how that's borne out with the 2L engine comparisons above. The only V8 listed is an exotic.

Erm.. The points I made are pretty much the same that you are making... If a 2L V8 can't possibly compete with a 2L I4, then a 4L V8 which will easily fit in the place of said 2L Inline 4 hasn't a chance in hell..

which then comes full circle to the original point of this thread, which is:

In order to simulate the sizes of (transverse) 4-cylinder motors that you see in production over the past few decades, the engine bays need to be larger.

I sort of agree. I think the engine bay sizes need tweaking, and I made some points above to this affect, however I think it will require a lot more than a larger engine bay.. A larger bay will allow a larger V8 as well so really doesn't solve anything.. The stats of the engines themselves need tweaking first before any real improvement can be seen.. if the engine calculations are fundamentally wrong then no amount of other changes will compensate.

From there I think the individual bodies could use some tweaking to for example make Inline 6's a viable alternative to V8s by increasing the length of the bays for cars of the 50s/60s/70s..

I thought about decreasing the width of some of the smaller bodies to give Inline engines a fighting chance, but looking at the specs of alot of these cars they already seem pretty narrow compared to a few period cars, and they have a hard enough time with Transverse engines already(If the transmissions scaled it would help this).. This makes me wonder if the V8s themselves are too narrow perhaps.

I mean I have no trouble fitting a 7.5L V8(116 bore x 88.9mm stroke) in a body the size of a Datsun 510(actually its narrower than the Datsun by about 200mm) ... At the same time, if I were to fit a copy of a Nissan L28 Inline 6 in the same car it wouldn't even come close to fitting.. Yet this is a mod that can be done in real life, unlike the 7.5L V8... Shit, if I bring up the stroke too I can get a whole 10L V8 in there with green width arrows.... This just isn't right.

So In summary:
1) Fix engine calculations
2) Make V8's wider
3) Make transmissions scale with engine size
4) tweak engine bay sizes
5)???
6) Profit!!!

[VicVictory]

So In summary:
1) Fix engine calculations
2) Make V8's wider
3) Make transmissions scale with engine size
4) tweak engine bay sizes
5)???
6) Profit!!!

Yes.

Oh, and I vote for "do a little dance" for number 5.

[Weasel]

Oh, and I vote for "do a little dance" for number 5.

And "make a little love"...

[VicVictory]

you know, pretty much "get down tonight."

[DeltaForce]

Yes, the more empty the engine bay is, the easier the engine is to service.

I imagine the gearboxes will also be reworked so their size reflects the type of gearbox and # of gears therein, and the size of the engine and flywheel? It sucks not being able to fit larger engines into tiny cars because the gearbox takes up 50% of the room and the engine is on one side. I'm not saying the engine needs to be huge, but some cars should be able to fit more than 1000cc transverse when there is room under the bonnet. Half that room is taken up by a 4speed manual gearbox that looks like it could be 10 speeds! :p

That explains why I can't fit even my 1.3 L four cylinder in any cars in a transverse configuration.

[VicVictory]

That explains why I can't fit even my 1.3 L four cylinder in any cars in a transverse configuration.

1.3L? Dear lord, how big is your bore? You're probably massively oversquare, that's your problem. Drop your bore a ton, raise your stroke to compensate.

I've managed to get as large as a 1.9L 4 in a small car, transverse.

[np1993]

Yes, the more empty the engine bay is, the easier the engine is to service.

I imagine the gearboxes will also be reworked so their size reflects the type of gearbox and # of gears therein, and the size of the engine and flywheel? It sucks not being able to fit larger engines into tiny cars because the gearbox takes up 50% of the room and the engine is on one side. I'm not saying the engine needs to be huge, but some cars should be able to fit more than 1000cc transverse when there is room under the bonnet. Half that room is taken up by a 4speed manual gearbox that looks like it could be 10 speeds! :p

That explains why I can't fit even my 1.3 L four cylinder in any cars in a transverse configuration.

I have only gotten a 1.2l NA I4 in a transverse. I don't even think my 800cc Turbo I4 fits in one.

[DeltaForce]

That explains why I can't fit even my 1.3 L four cylinder in any cars in a transverse configuration.

1.3L? Dear lord, how big is your bore? You're probably massively oversquare, that's your problem. Drop your bore a ton, raise your stroke to compensate.

I've managed to get as large as a 1.9L 4 in a small car, transverse.

It's actually a 1.3 L four cylinder square engine with 75 mm bore and stroke. I haven't had much success with getting long stroke designs to fit either. The width of the engine bays only allow the smallest of engines to fit transverse.

[VicVictory]

Hmm. The small car I submitted for Cheeseman's car reviewing thread has a 1.5L square bore engine, transverse. And it fits. With lots of room to spare. In the Honda Fit knockoff body.

Are you using double wishbone front suspension? That also reduces transverse engine size capability. McPherson strut is more compact, and what most RL compacts and subcompacts use.