🔍 Key Concepts

• Effect on cylinder lubrication when a unit is de-fueled but still moving with the engine • Difference between normal firing lubrication needs and lubrication needs for a cylinder that is not firing • Consequences of both too much and too little cylinder oil on an unfired unit (bore wash, scuffing, carbon build‑up)

💭 Think About

• Think about what happens inside that cylinder once the fuel is shut off but the piston and rings are still traveling up and down—what changes in temperature, pressure, and combustion byproducts? • Would a non‑firing (cold) cylinder need more, less, or the same lubrication as a hot firing cylinder to avoid damage? Why? • Which option could risk rapid bore wear or scuffing, and which could lead to excessive deposit formation or wasted oil in a cylinder that is not burning fuel?

✅ Before You Answer

• Consider the thermal load on a cylinder that is cut out compared with one that is firing normally • Ask whether you want to avoid over-lubrication (deposits, ring sticking) or under-lubrication (scuffing, wear) in a non-firing unit • Check which answer best matches standard practice when a cylinder is mechanically carried but not contributing power to the engine