Go to local dealer they will give you code for free id if you are not known
There is no corelation between a cylinders ID to OD.
The ID # is on the passenger side of the block just below the freeze plugs.
785.4 units2
Volume = 2.792 cubic feet.
with your vague discription, id say master cylinder is shot.
You might be able to trace the id # (just in front of #2 cylinder) at mortec.com
Monday November 07, 2011Sears Secret Santa SweepstakesSpin ID: KF7929028 Kay F. $3,000 CashSpin ID: KF8042489 Karl F. $11,400 CashSpin ID: MS08524 Marlene S. $42,350 Cash
if you mean a cylinder with a hole through it like a pipe or tube, then it's pi x (Od2 - id2)/4 x h Od = outer diameter id = inner diameter
http://forums.vwvortex.com/zerothread?cmd=print&id=3977482
Google volume of a cylinder. once you have the volume, plug in the density of water to get the mass.
While 8 cylinder trucks bring more horsepower and durability, 6 cyclinder diesel wins hands down. Diesel trucks are more fuel efficient, and with diesel mpgs run circles around standard gas trucks. so if i were you id go 6 cylinder diesel