Ensuring that your engine is well lubrication at all times is a critical element of maintain engine reliability and should be a key consideration of any modification project. Oil and its viscosity are responsible for lubricating all the moving parts within your engine and for reducing friction between the moving parts. However, oil also removes contamination, inhibits corrosion, improves internal sealing, and cools the engine by carrying heat away from the moving parts. All of these, and especially heat and contamination, can cause oil’s viscosity to break down over time, reducing the oil's ability to lubricate and protect the engine.
However, ensuring your engine oil retains its viscosity is not the only consideration when it comes to ensuring that your engine is well lubricated under all conditions. You also need to ensure that the supply of lubrication remain sufficient when the car is subject to lateral and longitudinal forces under hard cornering, and hard acceleration and braking. These lateral and longitudinal forces can cause the oil to slosh around in the oil pan or sump, which in turn can cause the oil pickup to surge and starve the oil pump. The result is a momentary lack of lubrication which will shorten the lifespan of you engine.
Fortunately, there are a number of simple modifications that you can perform to improve your engine's lubrication system and prolong your oil life. Then there are some more complicated solutions, such as a dry sump system that you could consider if you are serious about wringing the last bit of horsepower from your engine.
The Oil Pickup and Surroundings
One area to consider is the position of the oil pick up and the area around the oil pickup. The oil pickup tube should extend fairly deep into the sump without restricting the flow of oil into the pickup. You don't want the pickup right at the bottom of the sump as that is where heavy dirt particles and grime would settle.
Next, consider the area around the oil pickup. Is there a baffle plate that would trap oil around the oil pickup under heavy acceleration and braking? If there is none, consider fabricating and installing one preferably with a trap door on the side of the oil pickup that will allow oil to flow to the pickup but will prevent it from surging away under hard and aggressive driving.
You can also fabricate and install a horizontal, anti-slosh baffle plate slightly higher than the oil pickup to reduce the available flow area for oil to surge up and out of the sump. This baffle plate would need an opening for the oil pickup and additional openings to allow oil to drain back into the sump. This baffle plate must also not interfere with the movement of the crankshaft.
If you don't have the required fabrication skills, check your aftermarket parts supplier for an aftermarket sump or oil pan with the desired features. You might just be in luck, especially if your car is not too old or is a popular model for modification projects.
Increased Oil Capacity
One way of reducing oil starvation is to increase the volume of oil in your engine. The more oil there is in your engine, the less chance there is of oil starvation due to surging. However, just adding more oil to your engine is not the solution. Oil seals are not meant to bathe in oil as oil contains detergents to help keep the engine clean. These detergents tend to weaken the rubber in oil seals, which is usually a good thing as it keeps the seal soft. However, bathing the seal in oil makes the rubber too soft and prone to leaking. A better way of increasing oil capacity is to increase the volume or capacity of oil pan. This can take the form of fabricating and adding additional tanks to the sump, or widening the sump. There are also aftermarket sumps that hold a larger volume of oil.
Should you decide to fabricate your own large capacity oil sump, ensure that the increased capacity does not protrude below the car where it could be damaged should you ride over a rock or something. Also, if you add the additional capacity on the sides, ensure that it does not interfere with the movement of the suspension system and that there is sufficient clearance for the exhaust system. Installing additional capacity on the side will also make fastening the sump to the block a little more difficult. Ensure that you don't make it impossible.
If your car does not already have one, fitting a radiator-type, liquid-to-air oil cooler is another way of increasing oil capacity while it also prolongs oil life by reducing the effect of heat on the oil's viscosity.
The Oil Pump
There's not much you can do to the oil pump to relieve surging and starvation, but there are a few modifications that can help improve oil flow into the engine. Firstly, use a dremel tool match the opening of the oil pickup tube to the opening on the pump and smooth out obstructions and sharp bends as you would when porting the cylinder head. Do the same to match the oil pump opening to the oil gallery on the engine. This will improve the efficiency of the oil pump. However, remember not to open the oil passages too much as this will result in lower oil pressure. You may also be able to play around with the oil pressure if you have a gerotor type oil pump. The oil pressure on most gerotor type oil pumps have is regulated by a spring that can easily be shimmed to increase the oil pressure.
Dry Sump Lubrication Systems
The oil pressure from a dry sump lubrication system is consistent as it is not prone to surging as is the case in a wet sump. In a dry sump system the oil is stored in a separate tank or reservoir rather than in the sump pan. The oil reservoir, which is usually located in the trunk, is designed with internal baffles to prevent surging. It also has an oil outlet at the very bottom of the reservoir so the oil supply to the oil pump is uninterrupted and uninhibited.
The oil pump in a dry sump system has a minimum of 2 stages. One stage has a pressure regulator and draws oil from the oil outlet at the bottom of the oil reservoir and feeds it under pressure through the oil filter and into the engine. The other stage is responsible for scavenging oil out of the sump pan and feeds the oil back into the reservoir by way of an oil cooler.
Because the sump pan does not hold oil it is very shallow, allowing the engine to the fitted lower in the chassis and allowing you to lower the car's center of gravity.