Years ago older engines use the splash system ,so when the piston came down it must of picked up a bit of oil on the lower part of piston. Can someone explain how these new modern engines with oil pump & oil pressure get oil to lubricate the piston & cylinder walls. Hope Tester can add his knowledge on this. Thanks
The lower end of the connecting rod, the rod bearing, is fed pressurized oil from the crankshaft which is full of pressurized oil feeding all the bearings…On the “big end” of the connecting rods, one or more small holes are drilled to allow some of this pressurized oil to squirt up into the bottom of the piston and lube the wrist-pin, cool the piston and lube the cylinder walls piston rings…As the crankshaft turns, these holes are aimed over a wide area, keeping everything bathed in oil…
I hope my explanation helps you
On the older “splash” oilers a small cup was built into the side of the connecting rod. The last one I saw was a late 40s Hudson Commodore straight-eight.
Lawnmowers still use this system and incorporate an “oil flinger” The modern pressurized systems ‘charge’ the engine with pressurized oil that comes out of ports near or directly on all the major engine internals, providing far superior lubrication to the old splash systems.
Even without special oiling holes in the con rods, I’m pretty sure that a crankshaft being fed pressurized oil and spinning 3000+ rpm is probably thowing oil like a wet dog shaking itself dry.
Oldtimer 11–I believe that the Chevrolet 6 cylinder engines were splash lubricated up until 1953. The 1953 Chevrolet with the automatic transmission had an engine with full pressure lubrication. The manual transmission 1953 Chevrolet used a splash lubricated engine. In 1954, all Chevrolet engines had full pressure lubrication.
You are right about the Hudson straight eight engine. The Hudson 6 engine was also splash lubricated until Hudson brought out its 1948 models with the step-down design. This new 1948 Hudson featured a new flathead 6 engine with full pressure lubrication, but the 8 cylinder still had splash lubrication. The 6 cylinder engine introduced in 1948 was enlarged from 262 cubic inches to 308 cubic engines and became the powerplant for the Hudson Hornet which won many stock car races.
B.L.E. brings up a good point…Many engines get by with no holes drilled in the connecting rods because ample oil is spraying off the spinning crankshaft to lubricate the cylinders, pistons, wrist pins and rings…