Engine rebuild nearly ready. What cc does +40 give?

[SAKO]

Just a quick question gents.

I'm awaiting return of my bottom end, which is currently being rebored +40 using Omega pistons from PM.

Out of sheer curiosity what cc will this now give?

Burton used to have a list showing the increase in cc in relation to overbore sizes, but it doesn't appear to be there anymore, and I'm too thick to work it out.

Cheers.

[robertverhey]

Hi, 40 thou is 1mm so do your bore x stroke based on adding 1mm to the bore diameter.

If I remember my high school maths, the formula is 2 times pi times radius (half your new diameter) times stroke

Won't be much different from standard I don't think

Robert

[RogerFrench]

Capacity is Pi*Rsquared*stroke*no. of cylinders.

Your 40 thou overbore gives 1595 cc.

[elj221c]

According to my book of notes I give you:-

3.25" +00 82.550mm 1558cc
3.26" +10 +.254mm 82.804 1567
3.27" +20 +.508 mm 83.058 1577
3.28" +30 +.762mm 83.312 1586
3.29" +40 +1.16mm 83.566 1596
83.50 1594
85.0 1651
86.0 1690

[SAKO]

A whole 38cc! Well that's enough to power a good lawnmower. I hope my spine can cope with the extra G- force.

Cheers Guys.

[robertverhey]

Oops yes 2 x PI x radius is circumference....with apologies to my maths teacher, turning over in his grave no doubt