Drilling Big Block Chevy Oil Pan Rails: The Ultimate Guide

Drilling big block Chevy oil pan rails is a complex process that requires careful planning and execution. It involves several steps, including preparing the oil pan gasket surface, installing the oil pan gaskets, and ensuring proper torque specifications. The process aims to achieve a secure fit for the oil pan, preventing leaks and ensuring efficient lubrication for the engine. It is important to follow the correct sequence and torque values when tightening bolts to avoid oil leaks and engine damage.

How to install an oil pump and pick-up

To install an oil pump and pick-up, you will need to first remove the engine from the vehicle if you are unable to get the oil pan off while it is still in the car. Remember to use a separate catch pan for the antifreeze, as this cannot be mixed with the oil.

Next, remove the oil pan, oil pump pickup, and oil pump. The oil pump pickup is pressed onto the oil pump, and the whole assembly can be removed by removing one or two bolts near the bottom of the oil pump.

Fit the new oil pickup to the new oil pump, but do not push it on too firmly. Put it on just enough so that it stays but is still movable. Using a small hammer and chisel, tap the oil pickup into the housing, ensuring it is in the exact same position as the old one.

Now, prime the oil pump with STP. Pour the STP into the oil pump and spin the pump enough to get the inside lubricated—at least three to four complete spins should do the trick. Make sure the oil pump drive rod has the metal or plastic end fitted properly on top of the oil pump, so that the oil pump rod does not bounce out.

Insert the oil pump up into the engine block, ensuring that the rod fits into the base of the distributor. If the rod does not fit, pull the oil pump down, turn the oil pump rod a little bit, and try again. Keep trying until the top of the rod fits into the base of the distributor. You will know when you have it right as you will be able to bolt the oil pump to the block.

Bolt the oil pump to the block, install the oil pan, and then install all other parts in reverse order of removal.

The benefits of a dry sump system

Dry sump systems are a method of managing lubricating motor oil in four-stroke and large two-stroke piston-driven internal combustion engines. They are commonly used in racing cars, high-performance sports cars, and aircraft. Here are the key benefits of a dry sump system:

Improved Engine Reliability

Dry sump systems were invented to address the issue of oil starvation during high-g loads when oil sloshes away from the pump's pickup tube, which can damage the engine. By using a separate oil reservoir and multiple pumps, dry sump systems ensure consistent oil pressure and prevent oil starvation, improving engine reliability.

Increased Oil Capacity

Dry sump systems utilize a large external reservoir, allowing for increased oil capacity compared to wet sump systems. This is particularly advantageous in high-performance applications where sustained cornering and high accelerations can lead to oil starvation in wet sump systems.

Improved Vehicle Handling and Stability

The separate oil reservoir in a dry sump system allows the engine to be mounted lower in the chassis, lowering the vehicle's center of gravity. This improves vehicle handling and stability by providing a lower coefficient of drag. Additionally, the external reservoir can be located away from the engine, allowing for better weight distribution.

Improved Oil Temperature Control

The increased oil volume in a dry sump system provides greater resistance to heat saturation. Additionally, the external reservoir is positioned away from the hot engine, and cooling capabilities can be incorporated between the scavenger pumps and the reservoir, resulting in improved oil temperature control.

Enhanced Oil Quality

In wet sump systems, oil sloshes against the crankshaft and other spinning parts, aerating the oil and reducing its effectiveness as a lubricant. Dry sump systems minimize oil aeration and de-aerate the oil by pumping it into a remote reservoir, maintaining its quality and protective properties.

Increased Engine Power and Efficiency

By removing oil from the crankcase and reducing viscous drag, dry sump systems increase engine power and efficiency. The removal of oil also reduces parasitic power loss. Additionally, the use of a thermos-type device in the oil tank can lower startup emissions by using warm oil instead of cold oil.

How to check your oil pump pickup height and pan depth

When drilling big-block Chevy oil pan rails, it is crucial to ensure the correct oil pump pickup height and pan depth. Here is a detailed guide on how to achieve this:

Measuring Oil Pump Pickup Clearance:

Before assembling your engine, it is essential to measure the clearance between the oil pump and the oil pan. This is a critical step that can significantly impact the performance of your engine. Here are two methods to ensure sufficient clearance and oil pressure:

Method 1: Using Clay and Calipers:

• Take one of the company's pans, pan gaskets, and oil pump pickups.
• Apply a thin piece of racer's tape to the pickup's screen to prevent clay from getting into the pickup.
• Use clay on the pickup screen and dry-fit the pan to the engine.
• Bolt the pan on and snug it up at all four corners.
• Remove the pan and use calipers to measure the thickness of the clay.
• Remove the gasket and re-measure the clearance to determine if you need more or less clearance.

Method 2: Using a Straightedge and Tape Measure:

• Lay a straightedge on the pickup screen and measure both sides in relation to the block rail.
• Place the straightedge across the rear of the pan and measure the depth of the sump.
• Measure the gasket's thickness to determine the total dimension available for the application.

Setting Oil Pump Pickup Depth:

To set the oil pump pickup depth correctly, follow these steps:

• Measure from the block rail of the pan to the bottom of the pan sump area using a machinist square.
• Mount the oil pump with the pickup onto the rear main cap.
• Subtract 3/8" from the pan depth and hold the square to the pickup to mark the correct height.
• Adjust the pickup to the marked height.
• Secure the pickup in place by brazing, welding, or using Loctite products.
• Re-verify the clearance after the pickup is secured to ensure it is 3/8" off the bottom of the pan.

Final Assembly:

Once you have confirmed the correct oil pump pickup height and pan depth, you can proceed with the final assembly steps:

• Clean all gasket surfaces on the block, timing cover, rear main cap, and oil pan.
• Apply a thin layer of sealant to the timing cover and block where the front rubber seal goes.
• Install the front and rear pan gaskets, ensuring proper alignment.
• Apply sealant to the rubber gasket joints and install the side rail pan gaskets, lining them up with the bolt holes.
• Place the oil pan over the gaskets and install the oil pan hardware.
• Torque the larger bolts to 12 ft-lbs and the smaller front bolts to 7 ft-lbs.

The importance of oil control baffles

Oil control baffles are an essential component of an engine's lubrication system, particularly in high-performance driving conditions. They help to maintain constant lubrication by preventing oil slosh during cornering, heavy braking, and acceleration. Without baffles, oil can splash around the bottom end of the engine, leading to oil starvation at the oil pump and resulting in poor oil pressure.

Oil control baffles work to direct the flow of oil towards the sump area during acceleration, ensuring a consistent supply of oil to the pump. They also help to prevent oil from moving forward and starving the oil pump during deceleration. This is especially important in performance street machines, where the stock open-bottomed sump is inadequate for effective oil control.

In addition to oil control baffles, crankshaft scrapers and windage trays also play a crucial role in maintaining proper lubrication. Crankshaft scrapers help to pull excess oil windage, while windage trays keep oil in the sump area and prevent it from being pulled into the rotating assembly.

By investing in quality oil pans with features such as oil control baffles, crankshaft scrapers, and windage trays, racers can ensure optimal engine performance and protect their bearings from the pain of oil starvation.

Overall, oil control baffles are a critical component in maintaining consistent oil pressure and preventing power-robbing oil movement, ensuring that the engine receives the lubrication it needs during high-performance driving conditions.

How to prepare your oil pan gasket surface

To prepare your oil pan gasket surface, you'll need to make sure that both the block and pan surfaces are clean and straight. Here are the steps you can follow:

• Use a putty knife or similar tool to carefully remove any old gasket material or RTV. Be careful not to gouge the block's rail surface, especially on alloy blocks.
• Check all the bolt holes and clean any sealant or surface corrosion with a wire brush. You may need to use a tap for this step.
• If reusing hardware, clean any sealant or corrosion with a wire brush.
• Count all your fasteners before starting the installation.
• Use a flat, solid surface to check the pan for straightness, then clean the rails and bolt holes.
• If the pan is chrome-plated, brush out the drain hole threads to remove any leftover flakes that could cause a leak.
• Check the operation of any internal trap doors in the pan. Some engine builders install these types of pans with the engine block in an upright position to ensure the doors are not stuck in the open or closed position.

By following these steps, you will ensure that your oil pan gasket surface is properly prepared, reducing the risk of leaks and improving the overall durability and performance of your engine.

Frequently asked questions