This page sizes and checks the loaded parts of the crank mechanism: the
cylinder liner, the head studs, the piston, its rings and pin, the
connecting rod with its bolts, and the crankshaft journals and cheeks.
Each section states the loads it accounts for, shows the geometry it
assumes, and compares the computed stress against the allowable limit for
the material you choose.
Start with the gas and inertia forces, not with this page. Peak cylinder
pressure and the forces on the crank come out of the thermal and dynamic
calculation; bring those numbers here rather than guessing them. Running
the engine you are designing through the ICE calculator first takes a
minute and makes every result below mean something.
The calculation stops at the first part that fails. When a computed stress
exceeds the limit you entered, the answer names the quantity, its value
and the limit it broke — that is the design telling you which dimension or
material to change, not an error in the tool.
The stress calculator runs on the Pro plan. Everything above — the
formulas, the allowable ranges and the reference values — is here to read
for free.
