🔍 Key Concepts

• Study the valve operating gear at the top of each cylinder – is there a camshaft directly above the valves, or do you see pushrods and rocker arms coming up from low in the block? • Look closely at the cylinder liner and water passages – does cooling water directly contact the outside of the liner (a wet liner) or is the liner surrounded by a solid casting with a separate jacket space (jacketed/dry liner)? • Examine the big end of the connecting rods on the crankpin – do you see a special fork-and-blade or hinged-strap arrangement typical of some marine V‑engines, or do the rods appear to be conventional side‑by‑side rods on the crankpin?

💭 Think About

• Based on what you see at the top of the engine, decide whether valve motion comes straight from a cam located over the valves, or is transmitted up by long rods from a camshaft in the crankcase. • Trace the blue cooling‑water passages around the cylinder and ask yourself whether the liner is directly washed by coolant or enclosed in a thicker casting that forms the jacket. • Compare what a fork-and-blade connecting rod should look like (one rod split like a fork with the other passing between the tines) to what is shown on the crankpin in the illustration.

✅ Before You Answer

• Confirm whether the camshaft location and presence/absence of long pushrods matches an overhead cam or an overhead valve with pushrods design. • Verify if coolant (blue) lies directly against the green liner surface (indicating a wet liner) or is separated by an additional wall (jacketed liner). • Check if there is clearly one forked rod and one straight "blade" rod sharing the same crankpin (hinged‑strap, fork‑and‑blade type) or two normal big ends placed side by side (conventional rods).