What a 350 small block supercharger does

A supercharger is a belt-driven air compressor that forces more oxygen into your 350 small block engine than it would normally draw in on its own. The engine burns fuel more efficiently when there is more oxygen available, which produces more horsepower and torque. A typical 350 small block without a supercharger makes between 250 and 350 horsepower depending on its condition and tune. With a supercharger installed, the same engine often produces 400 to 500 horsepower or more.

The supercharger bolts to the front of the engine and connects to the crankshaft pulley with a serpentine belt. As the engine runs, the belt spins the supercharger's internal rotor, which compresses incoming air and pushes it into the intake manifold under pressure. This happens continuously while the engine is running, unlike a turbocharger, which only builds boost when exhaust gases reach a certain speed.

Key Takeaways

  • A supercharger increases horsepower by forcing compressed air into the engine, typically adding 150 to 250 horsepower to a stock 350 small block.
  • Superchargers bolt to the front of the engine and are belt-driven, so they start producing boost when ready when you press the throttle.
  • A complete supercharger kit for a 350 small block costs between $3,000 and $8,000 depending on the brand and whether you install it yourself or hire a mechanic.
  • Installation requires removing the intake manifold and modifying the engine bay, and most people need a professional mechanic to complete the work.
  • You will need to tune the engine's fuel and ignition timing after installation to prevent engine damage and get the full benefit of the supercharger.

Types of superchargers for 350 small blocks

The two main types are positive displacement and centrifugal. Positive displacement superchargers, usually Roots-type or screw-type, move a fixed volume of air with each rotation. They produce boost when ready at low engine speeds and are popular for street cars because they feel responsive. Roots-type superchargers are the most common choice for 350 small blocks and produce a distinctive whining sound.

Centrifugal superchargers work more like turbochargers — they spin faster and faster as engine speed increases, so boost builds gradually. They are more efficient at high engine speeds but produce less boost at idle and low RPM. Centrifugal superchargers are quieter and run cooler than Roots-type, but they cost more and are less common on 350 small blocks.

For a street-driven 350, a Roots-type supercharger is usually the better choice because it delivers power when you need it and is easier to install. For a high-RPM engine or one built for the track, a centrifugal supercharger may be worth the extra cost and complexity.

What you need to install a supercharger

A complete supercharger kit includes the supercharger itself, the mounting brackets, the serpentine belt, an intake manifold designed to work with the supercharger, and an intercooler (which cools the compressed air before it enters the engine). Some kits also include fuel injectors, a fuel pump, and wiring harnesses. Popular brands for 350 small blocks include Edelbrock, Vortech, and Procharger.

Beyond the kit itself, you will need a fuel management system to adjust how much fuel the engine receives at different boost levels. Many people use a programmable fuel injection controller or a carburetor with a manual fuel pressure regulator. You may also need to upgrade the ignition system, spark plugs, and engine oil cooler depending on how much boost you plan to run.

If you are installing the supercharger yourself, you will need basic hand tools, a socket set, a torque wrench, and a way to safely lift and support the vehicle. You should also have access to a dyno (dynamometer) to tune the engine after installation, though some shops will do this as part of the installation service.

Installation steps and timeline

Installation begins with removing the air cleaner, intake manifold, and any accessories in the way. The supercharger mounting brackets bolt to the engine block, and the supercharger itself bolts to those brackets. The serpentine belt is routed around the crankshaft pulley and the supercharger pulley, then tensioned to the manufacturer's specification.

Next, the intake manifold designed for the supercharger is installed, along with the intercooler if the kit includes one. The fuel injectors or carburetor are adjusted or replaced, and the fuel pump is upgraded if needed. All hoses, belts, and wiring are connected and checked for leaks and proper routing.

The entire process typically takes 8 to 16 hours for a professional mechanic, depending on the kit and the condition of the engine bay. If you are doing the work yourself and are experienced with engine work, plan on 20 to 30 hours spread over several weekends. After installation, the engine must be tuned on a dyno to set fuel pressure, ignition timing, and boost level. This tuning step usually takes 2 to 4 hours and is critical — skipping it can damage the engine.

Cost breakdown for a 350 supercharger installation

A complete supercharger kit for a 350 small block ranges from $3,000 to $8,000 depending on the brand and type. Roots-type kits are usually on the lower end, while centrifugal kits and high-end brands cost more. Some kits include an intercooler and fuel management system; others require you to purchase these separately, which can add $1,000 to $2,000.

Labor costs vary by region and shop, but expect to pay $1,500 to $3,000 for professional installation. Dyno tuning after installation usually costs $300 to $600. If you need to upgrade the fuel pump, ignition system, or engine oil cooler, add another $500 to $1,500. A complete installation with all upgrades and tuning can total $6,000 to $12,000.

If you install the kit yourself, you save the labor cost but still need to pay for dyno tuning and any parts you do not already have. Many people find that hiring a professional is worth the cost because a poorly installed or tuned supercharger can damage the engine, which costs far more to repair.

Maintenance and reliability after installation

A supercharger adds stress to the engine because it runs higher combustion pressures and temperatures. The engine will need synthetic oil and more frequent oil changes — typically every 3,000 to 5,000 miles instead of 5,000 to 7,000. The serpentine belt should be inspected every 10,000 miles and replaced every 50,000 to 75,000 miles because the supercharger puts extra load on it.

The intercooler (if installed) should be cleaned periodically to remove dirt and debris that reduces cooling efficiency. Fuel injectors should be cleaned or replaced if the engine starts to run rough or loses power. Most supercharged 350 small blocks are reliable if they are properly tuned and maintained, but they will not last as long as a stock engine running at lower power levels.

Many people run supercharged 350s for years without major problems, but you should expect to spend more on maintenance and repairs than you would on a stock engine. If reliability is your main concern, a supercharger may not be the right choice. If you want more power and are willing to maintain the engine properly, a supercharger is a proven way to get it.

Frequently Asked Questions

Can I install a supercharger on a stock 350 engine?

Yes, but a stock 350 is not ideal for high boost levels because the pistons and connecting rods are not designed for the extra pressure. Most people run 8 to 10 pounds of boost on a stock engine without major problems, but anything higher risks engine damage. If you plan to run more than 10 pounds of boost, you should rebuild the engine with forged pistons and rods first.

Will a supercharger hurt my fuel economy?

Yes. A supercharged engine uses more fuel because it burns more air and fuel with each combustion cycle. You can expect fuel economy to drop by 20 to 40 percent compared to a stock 350, especially if you drive aggressively. If you mostly cruise at steady speeds and avoid heavy throttle, the loss will be smaller.

Do I need to upgrade my transmission for a supercharger?

It depends on the transmission and how much boost you run. A stock Turbo 350 or Turbo 400 can usually handle 150 to 200 extra horsepower, but anything more requires a rebuild with stronger internal parts. A manual transmission may also need upgrades to the clutch and flywheel. Ask your mechanic whether your transmission needs work before you install the supercharger.

How much boost should I run on my 350?

A stock 350 can safely run 8 to 10 pounds of boost. A built engine with forged pistons can run 12 to 15 pounds or more. Higher boost means more power but also more heat, stress, and risk of engine damage. Most street cars run 10 to 12 pounds as a balance between power and reliability.

Can I remove the supercharger later if I change my mind?

Yes, but it is a time-consuming job. You will need to remove the supercharger, reinstall the original intake manifold, and retune the engine. The cost is similar to the original installation. Most people who install a supercharger keep it because the power gain is too good to give up.