Bore × stroke × cylinders → cc, litres and cubic inches. Free, runs in your browser
= 5,735 cc = 5.74 L
Closest engine in the simulator
V8 7.0L Pushrod — 8 cyl, 104.8 × 101.6 mm, 7.01 L, 11.0:1
Measured on the simulator's dyno: 502 hp at 5,688 rpm, 648 N·m at 4,638 rpmSame bore, stroke, compression ratio and displacement as the Chevrolet LS7 7.0 V8.
V = π/4 · B² · S · n
B is the bore, the cylinder's diameter. S is the stroke, how far the piston travels between top and bottom dead centre, which is twice the crank throw. n is the number of cylinders. The first three terms are the volume of one cylinder — a circle of area π/4 · B² dragged along the stroke — and multiplying by n gives the engine.
Feed the equation millimetres and it answers in cubic millimetres, which is a number in the hundreds of thousands and no help to anybody. Divide by 1,000 for cubic centimetres, by 1,000,000 for litres. The LS7's 104.8 × 101.6 mm bore and stroke give 876.4 cc in one cylinder and 7,011 cc in eight.
What the equation leaves out is the combustion chamber. Displacement is swept volume only, so the space still above the piston at top dead centre is not part of it. That volume is the other half of the engine's arithmetic, and it belongs to the compression ratio calculator. A two-stroke is measured the same way, from bottom dead centre, even though the transfer ports uncover part way up and the trapped volume is smaller than the swept one.
One cubic inch is 16.387064 cc, and that figure is exact rather than rounded: the international yard and pound agreement of 1959 defines the inch as exactly 25.4 mm, so a cubic inch is 25.4³ mm³ with nothing left over. One litre is 1,000 cc by definition, which makes it 61.02 cubic inches.
| Quoted as | cc | Litres | Cubic inches |
|---|---|---|---|
| 1,000 cc | 1,000 | 1.00 | 61.0 |
| 1.6 L | 1,600 | 1.60 | 97.6 |
| 5.0 L | 5,000 | 5.00 | 305.1 |
| 350 ci | 5,735 | 5.74 | 350.0 |
| 427 ci | 6,997 | 7.00 | 427.0 |
| 6.2 L | 6,200 | 6.20 | 378.3 |
Cubic inches survive in American V8 culture because the engines were named that way and the names stuck to the parts catalogue. Everywhere else displacement is litres to one decimal, and motorcycles and small engines stay in cc because a tenth of a litre is a coarse step when the whole engine is a quarter of one.
A badge is a rounded marketing size, not a measurement. Bore and stroke are chosen for bore spacing, deck height, rod length and valve area, and the volume that falls out of those choices is almost never round. The badge then rounds it to the nearest tenth of a litre, or to the nearest convenient cubic inch, and the two roundings disagree.
The LS7 is the clean example: 427.85 cubic inches, sold as a 427 because that is what the 1960s big block was called, and simultaneously as a 7.0 litre when it is 7,011 cc. Ford's 5.0 Coyote is 4,951 cc, which is 302 cubic inches — the same 302 the badge dropped in the 1980s. The small block Chevrolet 350 is 349.8 ci, so the name rounds up by a tenth of a cubic inch and its 5.73 litres get quoted as 5.7.
None of this matters until you are comparing two engines, ordering pistons, or entering a class with a displacement limit. Then the real number is the only one that counts, and the calculator above prints it beside the badge size so the gap is visible.
Boring a block cuts the cylinder walls to a larger diameter so worn or scored bores clean up and oversize pistons fit. An overbore is quoted as the amount added to the bore: 0.030 in over means a 4.000 in cylinder becomes 4.030 in, which is 0.762 mm on the diameter and half that off each wall. The stroke does not change, so the crank, rods and deck height stay exactly as they were.
The gain is smaller than people expect. On a 4.000 × 3.480 in V8 — 349.8 cubic inches — that 0.030 takes it to 355.1. That is 5.3 cubic inches, 86 cc, and going 0.060 over roughly doubles it. Displacement rises with the square of the bore, so the same 0.030 in is worth more on a big-bore engine than on a small one, and worth almost nothing on a motorcycle single.
Two things move with it. The bore/stroke ratio rises, because the bore grew and the stroke did not, so a bored engine is fractionally more oversquare than it left the factory. And the wall gets thinner: how far a block can safely go is a property of that casting, which is what a sonic check measures, not a number you can read off a calculator. Enter the overbore in the field above and the ratio and the added volume both update.
Every engine below is measured on the same dyno in the same air, so the specific outputs compare directly. The roster's four-stroke petrol engines run from 29.9 hp per litre on the Utility Single 163cc to 309.8 hp per litre on the F1 V8 2.4L, a factor of 10.4 between the thinnest and the densest use of a litre. The F1 V8 2.4L is 2.40 L and makes 743 hp; the Utility Single 163cc is 163 cc and makes 5 hp.
| Engine | Cyl | Bore × stroke | Displacement | Induction | Measured peak | hp / L |
|---|---|---|---|---|---|---|
| Utility Single 163cc | 1 | 68.0 × 45.0 mm | 163 cc | NA | 5 hp @ 4,000 | 29.9 |
| Thumper 500 | 1 | 84.0 × 90.0 mm | 499 cc | NA | 28 hp @ 5,133 | 55.6 |
| V-Twin 1340 45° | 2 | 88.8 × 108.0 mm | 1.34 L | NA | 59 hp @ 5,500 | 44.1 |
| Diesel I4 2.0 TDI | 4 | 83.0 × 92.0 mm | 1.99 L | NA | 72 hp @ 5,000 | 36.0 |
| Boxer-4 2.0L | 4 | 84.0 × 90.0 mm | 2.00 L | NA | 114 hp @ 4,950 | 57.0 |
| Inline-4 2.0L | 4 | 86.0 × 86.0 mm | 2.00 L | NA | 117 hp @ 7,200 | 58.3 |
| LPG I4 2.0L (Autogas) | 4 | 86.0 × 86.0 mm | 2.00 L | NA | 105 hp @ 7,000 | 52.3 |
| F1 V8 2.4L | 8 | 98.0 × 39.8 mm | 2.40 L | NA | 743 hp @ 19,250 | 309.8 |
| Inline-5 2.5L Turbo | 5 | 82.5 × 92.8 mm | 2.48 L | Turbo | 413 hp @ 7,000 | 166.5 |
| VR6 2.8L 15° | 6 | 81.0 × 90.3 mm | 2.79 L | NA | 154 hp @ 4,600 | 55.0 |
| Diesel I4 2.8L Turbo | 4 | 93.0 × 103.0 mm | 2.80 L | Turbo | 153 hp @ 4,200 | 54.7 |
| Boxer-6 3.0L | 6 | 91.0 × 76.4 mm | 2.98 L | NA | 189 hp @ 5,267 | 63.5 |
| V6 3.0L 60° | 6 | 89.0 × 80.0 mm | 2.99 L | NA | 194 hp @ 7,500 | 64.9 |
| Inline-6 3.0L | 6 | 84.0 × 90.0 mm | 2.99 L | NA | 194 hp @ 5,200 | 64.7 |
| Turbo I6 3.0L | 6 | 86.0 × 86.0 mm | 3.00 L | Turbo | 385 hp @ 7,000 | 128.6 |
| F1 V10 3.0L | 10 | 98.0 × 39.8 mm | 3.00 L | NA | 902 hp @ 19,250 | 300.7 |
| U-16 3.8L Blown | 16 | 60.0 × 84.0 mm | 3.80 L | Blown | 199 hp @ 4,317 | 52.3 |
| V8 4.6L SOHC | 8 | 90.2 × 90.0 mm | 4.60 L | NA | 269 hp @ 5,117 | 58.5 |
| V12 6.0L 60° | 12 | 84.0 × 75.0 mm | 4.99 L | NA | 392 hp @ 6,042 | 78.7 |
| V8 5.0L 90° | 8 | 94.0 × 90.0 mm | 5.00 L | NA | 298 hp @ 7,000 | 59.6 |
| Diesel I6 5.9L Turbo | 6 | 102.0 × 120.0 mm | 5.88 L | Turbo | 212 hp @ 3,000 | 36.0 |
| W12 6.0L | 12 | 84.0 × 90.2 mm | 6.00 L | NA | 426 hp @ 5,270 | 71.1 |
| Supercharged V8 6.2L | 8 | 103.9 × 90.9 mm | 6.17 L | Blown | 534 hp @ 6,200 | 86.6 |
| W18 6.3L | 18 | 76.5 × 75.6 mm | 6.25 L | NA | 494 hp @ 5,688 | 78.9 |
| Diesel V8 6.7L HD | 8 | 107.0 × 92.0 mm | 6.62 L | NA | 221 hp @ 4,500 | 33.3 |
| Turbo Diesel V8 6.7L | 8 | 107.0 × 92.0 mm | 6.62 L | Turbo | 595 hp @ 4,500 | 90.0 |
| V8 7.0L Pushrod | 8 | 104.8 × 101.6 mm | 7.01 L | NA | 502 hp @ 5,688 | 71.6 |
| Diesel V8 7.3L Power Stroke | 8 | 104.4 × 106.2 mm | 7.27 L | Turbo | 226 hp @ 3,300 | 31.0 |
| W16 8.0L Quad-Turbo | 16 | 86.0 × 86.0 mm | 7.99 L | Turbo | 1,038 hp @ 6,800 | 129.8 |
| V10 8.4L | 10 | 103.0 × 100.6 mm | 8.38 L | NA | 615 hp @ 6,200 | 73.3 |
| Vedeneyev M-14P (9-cyl radial) | 9 | 105.0 × 130.0 mm | 10.1 L | Blown | 341 hp @ 3,100 | 33.6 |
| H-24 36.8L Supercharged | 24 | 127.0 × 121.0 mm | 36.8 L | Blown | 1,728 hp @ 3,850 | 47.0 |
| X-24 42.5L Aero | 24 | 127.0 × 139.7 mm | 42.5 L | Blown | 1,378 hp @ 2,902 | 32.5 |
| P&W R-2800 Double Wasp (18-cyl twin-row) | 18 | 146.1 × 152.4 mm | 46.0 L | Blown | 1,966 hp @ 2,900 | 42.8 |
| Diesel V16 60L | 16 | 159.0 × 190.0 mm | 60.4 L | Turbo | 2,541 hp @ 2,100 | 42.1 |
Read the rpm column beside the last one and the pattern is obvious. Displacement fixes the air per cycle; power is that air times the cycles per minute, so the engines at the top of the specific-output list are the ones that either turn fastest or pack the most into each stroke. Boost does the second, which is why the turbocharged rows sit above naturally aspirated rows of the same size. Revs do the first, and the limit there is mean piston speed rather than displacement — the subject of the bore and stroke calculator.
Compare the fuels in the table and the diesels look oversized for what they make. The roster's four-stroke diesels have a median of 36.0 hp per litre against 63.5 for the petrol engines, and their median power peak arrives at 4,200 rpm against 5,500. Power is torque times rpm, so an engine that stops turning at 4,200 has to find its output in torque, and torque comes from displacement.
The rpm ceiling is not arbitrary. Diesel combustion starts when the fuel is injected and burns as it mixes, so there is a floor on how few milliseconds the burn can occupy, and the heavy pistons, rods and crank a 17:1 compression ratio needs do not want to go there anyway. Hence the shape of the roster: 2 naturally aspirated diesels averaging a modest specific output, and 5 turbocharged ones that use boost to make the same litres do the work of more.
The practical version: for the same power a naturally aspirated diesel needs noticeably more displacement than a petrol engine, and a turbo diesel needs less than that but still more than a turbo petrol. Sizing a diesel by the litre count of a petrol engine you liked gives you an engine that pulls a house down at 1,500 rpm and runs out of breath before 4,000.
Displacement is the volume every piston sweeps between top and bottom dead centre, added up across the cylinders. It is a measure of how much air the engine can move in one cycle, which is why it predicts torque better than it predicts power. It does not include the combustion chamber above the piston at top dead centre: that volume sets the compression ratio, not the size.
Take π/4 × bore² × stroke for one cylinder, then multiply by the number of cylinders. With bore and stroke in millimetres the answer is in cubic millimetres, so divide by 1,000 for cc. A 104.8 × 101.6 mm V8 works out at 7,011 cc, which is the 7.0-litre LS7.
Multiply cubic inches by 16.387064 to get cc, then divide by 1,000 for litres. So 350 ci is 5,735 cc, or 5.74 litres. The factor is exact rather than measured, because an inch is defined as exactly 25.4 mm.
No. Across the simulator's four-stroke petrol engines the measured spread runs from 29.9 hp per litre to 309.8 hp per litre, a factor of 10.4. Displacement sets the air per cycle; power is that air multiplied by how many cycles a minute the engine survives, and by how hard the induction packs each one. A small engine that revs or boosts beats a big one that does neither.
Very little, and it grows with the square of the bore. A 0.030 in clean-up on a 4.000 × 3.480 in V8 takes it from 349.8 to 355.1 cubic inches, about 1.5 %. That is why a stroker crank, not a bigger bore, is how people find real cubic inches.
Because the badge is rounded and the engine is not. Ford's 5.0 Coyote measures 92.2 × 92.7 mm across eight cylinders, which is 4,951 cc — 302 cubic inches, the number the same engine family was sold under for decades. Marketing rounds to the nearest tenth of a litre, and it rounds up more often than down.
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