# Minimum cylinder displacement

Discussion in 'Car Comparisons' started by chornedsnorkack, Jan 20, 2010.

1. #1
How much displacement does a cylinder of a benzine burning, 4 stroke otto engine need to function?

Many engines with large number of cylinders are big engines. But not all are.

For example, the early, 1950s Ferraris have just 2 l displacement for V12. Just 166 ccm per cylinder.

How would the performance of a 2 l Ferrari V12 compare against a 2 l ordinary straight-six or flat-four? And how would the space taken up by the engine compare?

BRM built a V16 racing car with under 1,5 l displacement. Just 93 ccm per engine.

Would you prefer a 1,5 l V16 or a 1,5 l inline four?

2. #2
isnt like, less cilinders, more torque, when same displacement?

3. #3
I'm no expert, but I would say #\$%# no to that.

4. #4
it basically ends up as a tradeoff between cycle efficiency, reliability, and friction.

more cyls tend to increase cycle efficiency, but decrease reliability and increase frictional losses.

5. #5
Last edited by a moderator: Apr 25, 2016
6. #6

because the 2l v12 has smaller pistons and probably a much shorter stroke. the pistons are one lighter, and are probably capable of higher rpms vs longer stroke heavier piston 2L 4 cylinder or 6 cylinder.

because the parts are lighter, they can spin faster. going off the basic formula

hp = (torque x rpms) / 5252

in the v12 i can replace torque for rpms, string that v12 to 9k rpms probably. even if that v12 only produced 300hp at that rpm i need just 175ft lbs of torque. pretty doable with that small of a engine.

but even take a 2L 4 cylinder NA tuned engine. Like the 250R Zetec motor.

it produces 250bhp at probably a much lower 7k rpm vs the 9k, and ~185 torque, because of its heavier pistons and longer strokes

but given that, the 4 or 6 cylinder would more than likely put out more torque but not always

at any rate you will be looking at the applications...

if i had a extremely light car (less than 2400lbs) and built for track use, i would choose a 1.5L v16 turbo producing some stupid 800bhp...

for economy normal car use, the 1.5L inline 4...

7. #7
welcome back

8. #8
I'd love to have a light mid engined sports car with a small displacement, over-square flat plane crank V8 such as those found in a lot of 60s and 70s Italian sports cars.

Something like the one in the Alfa T33 Stradale would be perfect:
"The race-bred engine bore no relation to the mass-produced units in Alfa's more mainstream vehicles. Race engineer Carlo Chiti designed an oversquare (78 mm bore x 52,2 mm stroke) dry-sump lubricated 1,995 cc (121.7 cu in) V8 that featured SPICA fuel injection, four ignition coils and 16 spark plugs. The engine used four chain-driven camshafts to operate the valve train and had a rev-limit of 10,000 rpm. The engine produced 230 bhp (172 kW) at 8,800 rpm in road trim and 270 bhp (200 kW) in race trim."

9. #9
thanks, been awhile since ive been active but with all my new free time, ill be around.

good to see your still active as well