# B17 Crank into LS

#### 22crazy

##### Senior Member
is there a way to calculate the displacement using the stroke, bore, rod lenght? oh yah what about putting in a b17 crank into an ls...would that help to rev higher...and what are the draw backs

#### lsvtec

##### GNU/Linux Evangelist

Yes, if you know bore and stroke you can calculate displacement.
Displacement in cc's (divide by 1000 to get liters) = r^2 * 3.14159 * stroke (in centimeters) * 4
r = 1/2 the bore in mm * 10
Yes, you can run a B17 crank in an LS engine, you lose displacement.

#### K2e2vin

##### Senior Member
Originally posted by lsvtec@Feb 2 2003, 10:33 PM
r^2 * 3.14159 * stroke (in centimeters) * 4
r = 1/2 the bore in mm * 10

simpler way to say it- pi(r^2)s*cylinders=displacement
convert to cm (for mm to cm, move decimal one to the left), r=.5*bore, s=stroke

if you are using custom rods or something (shorter rods) deck height-.5s-rod=x
replace the s with the x in the formula above and add that to the answer you got.

ex: b18c block, b18c rods, b17 cranks;
3.14(4.05^2)8.14=419.4cc per cylinder, 1677.6cc total
18.15-(8.14*.5)-13.79=.29cm; 3.14(4.05^2).29=14.94cc per cylinder, 59.76cc gained