A start-up in which bearings, gears or cylinder walls turn before the pump has delivered oil or a film has formed. Mechanics blame a large share of total engine and gearbox wear on dry starts, especially after long shutdowns, on cold days with thick oil, or after a rebuild where nobody pre-lubed. The fixes are pre-lube pumps, priming filters, oiling bearings on assembly and assembly lube on cam lobes.
Prime that filter and spin the pre-lube pump first, I don't want a dry start on a fresh rebuild.
Also heard as
- dry startup
Related terms
Boundary lubrication
Regime where surfaces touch through the oil and protection comes from chemical surface films, not fluid pressure.
Running-in
Early period when new contacting surfaces wear and smooth each other until they settle into a stable state.
Adhesive wear
Wear where touching asperities weld together and tear, moving metal from one surface to the other.
Scuffing
Sudden, severe adhesive damage where the oil film fails and sliding surfaces locally weld and tear.