Mondello oiling systems are specially designed for Oldsmobile engines, but you can also modify factory-designed oiling systems to make them work. Let’s start with oiling system basics and then go over the modifications necessary for Oldsmobiles.
Oiling System Basics
Oiling System Purpose
A car’s oiling system pumps oil throughout the engine to reduce friction and cool and clean the engine.
When the various engine parts move next to one another, they rub together, creating friction. The energy used to overcome this friction is converted into heat rather than movement. As the parts rub together, minute irregularities in their surfaces hit each other and break off, wearing the materials down.
Engine oil’s job is to separate the moving parts to minimize friction, thus reducing heat and wear.
Engine oil further cools the engine by absorbing heat and transporting it to the oil pan, where the heat is dispelled into the surrounding space. In some oil pans, cooling fins help to lower the temperature of the oil.
As oil is pumped throughout the engine, it picks up any contaminants along its way, filtering out the larger particles through the oil filter and holding onto the smaller ones until the next oil change. This is possible because of detergent chemicals, which are added to the oil during the refining process to prevent the particles from being dispersed onto surfaces.
Oil also helps keep the engine shiny and rust-free by preventing oxygen from coming into contact with the metal parts and corroding them.
Oiling System Parts
The oil pump, oil pick-up tube, oil filter, and oil pan or sump make up the oiling system.
The oil pump sits inside the oil pan, from which it sucks up oil. It then pumps the oil along the various oilways throughout the engine before returning it to the oil pan and recirculating it. In most engines, the oil pump is driven by the crankshaft.
Oil Pick-Up Tube
When the oil pump sucks up oil, that oil flows into the pick-up tube, which sits just above the bottom of the oil pan. The length of your oil pick-up tube will depend on the volume of your oil pan.
Before oil enters the engine, it is pumped through a filter that removes any metal fragments and dirt particles, which could wear down the engine parts significantly if not removed. The oil filter is typically located near the bottom of the engine so that it is the first thing the oil flows through.
Oil Pan / Sump
Sometimes called the “sump,” the oil pan is a metal dish that adheres to the bottom of the engine block and holds any oil that’s not currently in circulation.
The oil pan also assists in cooling oil after it returns from being circulated throughout the engine. As a car moves along, air flows under the oil pan, dissipating the heat of the oil inside. The car’s bodywork may even be designed in a way to direct air toward the oil pan, thus boosting its cooling capabilities.
Note: The sump described above is known as a wet sump system because it contains oil, and is standard in most vehicles. However, oiling systems may contain dry sump systems, which store the oil in a remote container.
Oiling System Modifications for Oldsmobile Engines
Certain modifications to factory-designed oiling systems may be necessary for use in Oldsmobile engines.
Ensure that the oiling holes in the crank are smooth, clean, and burr-free for smooth transition and improved oil flow. Mondello’s Nodular Iron Performance Crankshaft is made of 5340 nodular iron for strength and durability.
We strongly recommend restricting the main cap passages to reduce oil flow to the top end of the engine. This will keep a sufficient amount of oil available for the reciprocating assembly. Mondello sells oil restrictor kits to make installation easy.
Oil Passage Porting
Porting the passages from the oil pump to the crankshaft can help remove excess flash, ease the transitions, and smooth out the corners, allowing the oil to flow freely. Mondello’s SP-765 Oil Pump has been ported and features a larger diameter hole for moving a larger volume of oil.
To increase the pressure of your oil pump, you can purchase the heavier oil pump bypass spring found in Mondello oil pumps, or shim your existing spring up to 0.08 in either direction. If you choose to adapt your existing spring, keep in mind that the oil pump gears must be of equal length and should project 0.008 to 0.009 inches out of the pump body (surface grinding of the oil pump body may be necessary).
Aftermarket oil pans and pick-up tubes may require some adaptations. The clearance between the pick-up tubes and the oil pan should be between 0.25 and 0.5 inches. Don’t forget to include the gasket thickness in this measurement. If the oil pan will not bolt on and you can’t see anything that’s in the way, check the number 2 main cap studs, which could be hitting the pan if they aren’t bottomed out in their holes. If they still hit the pan after being bottomed out, grind them down a bit to shorten them. Your last resort if you still have a clearance issue is to heat the oil pan above the number 2 main area and tighten it down while it’s still hot, without the pan gasket in place. After the pan cools, reinstall the pan gasket.
Note that you should always do a dry fitting before gluing down gaskets or adding oil, and check for clearance of the pick-up tube in relation to the bottom of the pan.
For those who don’t want to have to make these modifications, Mondello provides a number of complete oiling systems and oiling system parts for all Oldsmobile engines.