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# How to calculate engine capacity?

### General Engine Building Discussion

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We have a 4g54b turbo Mitsubishi starion that we are going to tune it has .040 over wiseco pistons, how can i calculate the cc's to tune for VE

this will be my first car i tune it is my uncles as he wants this to be my test car thanks... specs below

Stock factory bore: 3.5870 = 91.1098 mm

Stroke :3.8580 = 97.9932 mm

Bored over: 0.040 =92.1258 mm new bore so how can i get the cc's?

You need to calculate the cross sectional area of the bore and then multiply it by the stroke to calculate the volume of a cylinder. Multiply this by the number of cylinders.

The stroke and bore spec I have is 98 x 91.1 mm btw.

So bore radius is 92.2/2 = 46.1 mm

Area is pi x r ^2 = 3.142 * 46.1^2 = 6677 mm^2

Volume = area x stroke = 6677 x 98 = 654301 mm^3

Engine volume = volume x # cylinders = 654,301 x 4 = 2,617,205 mm^3

So the engine capacity is 2.617 litre or 2617 cc

Thanks yea i figured i should round off the stroke for a total of 98mm thanks for the reply