Cylinder Volume Correction

[jahorgos]

I need to correct the cylinder volume in my tune as my motor has been bored a half mil over which I am told by the builders is the same as 20 over or I believe otherwise displayed as .020

In HPT they describe cylinder volume as:

Cylinder Volume: The volume (displacement) of one cylinder.

The size before the bore was a stock 0.49951 cylinder volume.

My question being what would the new cylinder volume be? I've tried some calculations but I don't want to get this wrong so I would appreciate some help. Thanks!

P.S. This is a 2006, 2.0 LSJ Supercharged.

[BennyHHR]

0.50247

[jahorgos]

0.50247

How do you calculate that number?

[BennyHHR]

Just simple math....

PM'd ya, too.

For everyone else:

Cyl Vol = (bore dia./2) squared * Pi * stroke

[redhardsupra]

http://redhardsupra.blogspot.com/200...readsheet.html

[Sunburst_SS]

so, if we were to calculate this....we would use the measurments in inches correct??? So for our stock motor with the engine bore of 3.39" (86mm) and a stroke of 3.78" (96 mm) the equation would look like...

cyl. vol. = (3.39/2)squared * 3.141... * 3.78

[TiredGXP]

so, if we were to calculate this....we would use the measurments in inches correct??? So for our stock motor with the engine bore of 3.39" (86mm) and a stroke of 3.78" (96 mm) the equation would look like...

cyl. vol. = (3.39/2)squared * 3.141... * 3.78

That looks correct. I haven't downloaded Marcin's spreadsheet but I assume that he has just added the conversion from cubic inches to litres as *(2.54^3)/1000.

[Sunburst_SS]

what would you use the (2.54^3)/1000 on??? The final # you get from the cyl. vol???

[TiredGXP]

what would you use the (2.54^3)/1000 on??? The final # you get from the cyl. vol???

Yeah, that is just the conversion from cubic inches to litres. Applying the formula and your bore/stroke I get 34.1178 cubic inches or .559091 litres/cylinder.

[jahorgos]

Yeah, that is just the conversion from cubic inches to litres. Applying the formula and your bore/stroke I get 34.1178 cubic inches or .559091 litres/cylinder.

Something is wrong here because our stock is listed as: 0.49951

[TiredGXP]

You're right, something is wonky:

I believe that the ecotech 2.0 has an 86mm bore and an 86mm stroke (as oposed to the numbers quoted above), which works out to a stock cylinder volume of .499557, pretty damn close to the advertised displacement of 1.998 litres.

So a .020 inch over cylinder has a bore of 86.508mm, which then yields a cylinder volume of .505476.

[Sunburst_SS]

yea, I may of had the wrong measurements....I just did a quick search on google, and I guess that isn't always accurate lol. I was just making sure I had the formula correct....thanks man

[BennyHHR]

I messed up my original calc. Too much of a hurry, I guess.

Hey, the OP stated that the overbore was 0.5 mm (close to 0.020 in.). All the dimensions here are metric. Why do people want to go back and forth between metric and inches??

The stock bore and stroke is 86 mm. With the stated overbore of 0.5 mm, plugging the numbers into my computer calc gives 0.50538.

[TiredGXP]

Hey, the OP stated that the overbore was 0.5 mm (close to 0.020 in.). All the dimensions here are metric. Why do people want to go back and forth between metric and inches??

Just bad habits

I live in a country that "officially" went metric 30 years ago, but grew up with Imperial measurements, and go back and forth between them all the time.