too many cylinders?

[454Casull]

I would like for us to have individual electronically-acutuated rotary valves, in fact. Seems like the best of both worlds.

[YellowMaranello]

Originally posted by 454Casull
I would like for us to have individual electronically-acutuated rotary valves, in fact. Seems like the best of both worlds.

You could make some and make millions, that is, if internal combustion engines stick around...

[BeEfCaKe]

Going back to the mucho-cylinder engine... i was thinking, how big of a gas tank would i need to travel say... 100miles or wahtever? Also, as the car begin to carry more gas, its also increasing weight, both through the fuel itself, and also the tank inwhich to contain it...



obviously, if such an engine were really made, it probably won't be a street car, but drag/race-only type...

[ivymike1031]

Originally posted by Heep
I've thought about that as well. But consider engines of the exact same size...a 6 liter 8 cylinder, or a 6 liter 60 cylinder. I assume the 60 would have a FAR higher redline, but that the 8 would have FAR more torque. Just what I'm assuming, anyway. Input?

The '60 would have a spaghetti noodle for a crankshaft - it wouldn't last.

Also, as you break the displacement up amongst more and more cylinders, you increase the surface area. Sooner or later, you'll be sending nearly all of your fuel energy into the cooling jackets instead of the crankshaft.

[454Casull]

Maybe that's why cylinders are cylinders and not rectangular prisms.

[Porsche]

Originally posted by 454Casull
Maybe that's why cylinders are cylinders and not rectangular prisms.

LMAO! Some old lego cars had some square ones.


So going the opposite way, why don't we have 1 Cylinder 6 liter engines? Or more practically, as in old steam ships, the 3 Cylinder (I know cars aren't steam powered, so it would just be a 3 Cylinder rather than the triple Expansion three cylinder.) My frined's dad said he saw a bus with a 3 Cylinder, massive, is this right? I thought buses were all 6, 8 and 10's.

[ivymike1031]

I'm sure that there are several thousand single cylinder 6L engines in the world.

Most buses that I'm familiar with use straight-six diesel engines (although there are some I4's around too, and probably some others that don't come to mind).

For most applications, steady delivery of torque is desired. Having multiple cylinders (3 or more) makes this goal easier to achieve. It is also common to want smooth, vibration-free operation, and engines with 6 or more cylinders have a leg up on the competition in this department. Packaging concerns also play - a single cylinder engine is squat, while an inline six is long and slender.

The largest-displacement engine that I have direct experience with was a natural gas fired 22L/cyl V18 (396L total).

[454Casull]

The largest-displacement engine that I have direct experience with was a natural gas fired 22L/cyl V18 (396L total)

Oh, you saw it? I had it in my toy train set. I wonder where it is now...

[Shaw]

I saw your post on the CSRV rotary valve system and thought you should know that Porsche has already stepped up to the plate and has bought a license for the system. You may be able to take one of the new models for test drive in the near future

[Thunda Downunda]

Originally posted by ivymike1031
For most applications, steady delivery of torque is desired. Having multiple cylinders (3 or more) makes this goal easier to achieve .. The largest-displacement engine that I have direct experience with was a natural gas fired 22L/cyl V18 (396L total).

.. and then there's the famous Honda 125cc 5cyl GP race-bike engine from the 60's

[replicant_008]

More cylinders equals more complexity, more moving parts and the associated reliability and friction losses...

In some cases, particularly with smaller displacement engines the gains from the additional cylinders is offset by this issue. I'm thinking particularly of the Mazda I4 1800cc vs the Mazda 1800cc V6 (the twin cam 4 was a much better engine than the little 6) and the Altezza (Lexus IS200) which is available with either a I4 or and I6. The I4 is a torquier and more powerful engine but less smooth than the 6.

Incidentally...

The Southward Car Museum at Paraparaumu in New Zealand has a replica of a Chitty Chitty Bang Bang supercharged Mercedes 28/95 cars (built in 1914) with 6 cylinders. The engine was based on a Zeppelin aero engine and displaced 23 litres! That's the entire displacement of a Commodore V6 PER CYLINDER with 162mm bore and a 202mm stroke or in inches 6.377 inch bore and nearly 8 inch stroke... yikes!

[Evil Result]

hehe awesome

http://www.bigbikeriders.com/48cyl.htm

[MagicRat]

Most large ocean-going (non-military) ships these days use huge internal combustion engines where each cylinder has a bore and stroke of 3 to 4 feet or more. They burn bunker sea oil, which is something like diesel that didn't quite make the grade.
They turn at about 60 rpm, with very heavy flywheels. They are very efficient in producing huge torque numbers over a narrow rev range while burning a very low-grade fuel.

Compare that to something like an older Honda CB 400 motorcycle where each of the 4 cylinders displaced just 100 CC. The ship engine is more efficient for its application.
The question here is what is the measure of efficiency?
Cost of operation?
Cost of manufacture?
Power output?
Fuel economy?

Obviously, there is no one best answer, it depends on application.

[383PhoenixAm]

I'm going to go out on a limb and actually respond to the question here.
In my opinion, as there are more cylinders, I don't think that they would eventually become insignificant, rather than just less significant. Saying that all things are equal, and that such an engine was tuned perfectly, no cylinders should really be unable to account for any power. An engine as such-with 50 or 60 cylinders, could be experimented with in such a way that the power could become tremendous thanks to the individual cylinders. Two or more cylinders could be firing at once, amplifying the thrust effect on the crankshaft, or the cylinders could be configured to fire at close radius degree proximities to eachother, producing en ever-active force on the crankshaft. Any way this would work could be made to produce more power, no matter the number of cylinders. The thing is that after a while, after all the parts and stress on them from such an amount of power, the engine would become extremely impractical. It would waste fuel like crazy, produce far too much emissions, and be plain out impractical to use on anything. This is just a theory, though.

[Adamsindrey]

One thign that limits the amount of cylinders you cna have is your crank shaft. a reason manufacturers dont make straight engines like straight 8s or anything more than a 6 is because the longer you have the crankshaft the more it winds up as each cylinder goes through power stroke. a 60 cylinder engine wouldn't have a crank strong enough to harness the power succesfully.
4 cylinders are optimum in my oppinion, 3 cylinders are not as smooth and cant haul round bigger cars, 6 is propably second to 4 but pretty much anything you can do with 6 a 4s not far behind, and an 8! god dont get me started on the modern american car with its v8! bad performance+bad economy=bad engine