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Somebody once said it was harder to get more power from a bigger engine (in terms of bhp per litre).

E.g 220 BHP from a 2000cc engine is easier than trying to get 440 BHP from a 4000cc engine.

Not including cost etc purely technically speaking.

Is that true?

I wait with interest to hear what the engineers here say

I have read that there is an optimum capacity for a cylinder before it becomes less efficient (too small or too big) - I think somewhere around 375cc.

So, a bigger engine will need more pistons - so I assume will create more friction losses.

I'm sure it's much, much more complicated than this.............

RH1300S wrote:I'm sure it's much, much more complicated than this.............

Definately, Just think of the combustion in bigger cylinders. It will be less homogeneous because of the spark from the spark plug will be smaller compared to the amount of gas that has to combust.

And I think that the dissipation of heat will be a greater issue: An engine that is 2 times bigger has 2^3 times more volume (and let's say displacement), but it has only 2^2 times more surface to the outside world for the heat to get out. Ofcourse you can enlarge the radiators, but you will come to a point that upscaling is not enough.

Well it is harder for a bigger displacement engine to achieve higher revs... the C6R engine makes around 700 hp at around 6-7000 rpm but makes about 400 lbs. of torque. And this is before the air restrictor. I'm sure if somebody posted the hp eqn. it might help

lets think about a 2 litre 4 cylinder engine and a 5 litre 10 cylinder one. you can get 200 hp out of a free aspirating 2 litre engine at a modest cost(honda type r) whereas 500 hp out a a lambo v10 is already a really neat piece of engineering, and a v10 has better revving charachteristics than a straight four, by far, and the displacement per cylinder is the same(500cc). how come?

pyry, what does your signature mean?

Pyry, yo uhave ot remember that a Honda 4 cylinder engine is built for mass consumption, where no matter what vehicle it is place din, it is expected to give a long and reliable life. Whereas, a lambo is pure exotic, high performance is demanded. So reliability is much less. The Lambo engine is designed and runs at a higher level of performance that a Honda 4.

Aaaah so THATS why my Ford Fiesta makes about 100hp per litre were as an F1 car engine makes about 3-4times that!!!

What ford Fiesta makes 100 BHP per litre?

Spencifer_Murphy wrote:Aaaah so THATS why my Ford Fiesta makes about 100hp per litre were as an F1 car engine makes about 3-4times that!!!

B.S.

djones wrote:What ford Fiesta makes 100 BHP per litre?

DR_K13 wrote:

Spencifer_Murphy wrote:Aaaah so THATS why my Ford Fiesta makes about 100hp per litre were as an F1 car engine makes about 3-4times that!!!

B.S.

The Ford Fiesta RS Turbo has an engine with 1597 cc of displacement and gives you 133 bhp. This means 85 BHP per litre without any tuning. Close enough for me.

you missed my point, my point was that the bhp per litre is the same, although the lambo is higher tuned and a hell of a lot more expensive, how come this?
m3_lover: its an inside joke between me and a friend of mine(whos black)

There is no replacement for displacement