Big Power CNC Aluminum Cylinder Heads

Raylar Big Power CNC aluminum cylinder heads are engineered to maximize the horsepower and torque of the big block Chevrolet Vortec 8100 8.1L / 496 engine. Typical aftermarket cylinder heads are cast and machined ensure the head surface is flat. In addition to these basic steps, all Raylar Big Power heads are further CNC machined in the valve bowls, combustion chambers, intake ports and exhaust ports. We then port match our cylinder heads, maximizing airflow through the ports. These steps are usually an additional charge with aftermarket head manufacturers, but is standard on our heads.

Raylar uses stainless steel nitrated valves for maximum wear and durability. These valves measure 2.19 / 1.75 and have thinner 11/32 valve stems to enhance airflow. These valves are set in bronze guides for maximum reliability. Our heads come with special high-lift dual valve springs with dampers, built to work with our high-lift series of camshafts and use CNC chromoly retainers. Instead of rubber seals, these heads feature viton valve stem seals for added durability.

These heads work best with our stainless steel roller rockers and self adjusting locking AFN nuts. Roller rockers reduce valvetrain friction, freeing up an additional 18 horsepower! Raylar cylinder heads are direct replacement bolt-on parts for any 496cid / 8.1L engine. All of our parts fit under the stock valve covers.

Fits Any Vortec 8.1L / GEN7 BBC 496cid:

  • 8.1L / 496 MAG H.O.
  • Crusader 8.1 MPI / 8.1HO MPI Captains Choice
  • GM 8.1L 8100 / Vortec L18
  • GM Vortec Marine HP1 / HP2 / HP3
  • Indmar 8.1 / 8.1HO Malibu & Mastercraft
  • Levitator 8.1 /496cid
  • Mercury Marine 496MAG / 496HO
  • Volvo Penta Marine GS8.1 / GSX8.1 / 8.1Gi / 8.1GXi

vortec 8100 8.1L 496 performance cnc cylinder heads
Big Power CNC Aluminum Cylinder Heads - $2995

Our Big Power CNC aluminum cylinder heads out flow every other cylinder head on the market. Expect huge performance gains across the entire powerband.

  • Lightweight A356T56 Alcoa Alloy Aluminum
  • Smooth Cast, 5 Axis CNC Centers Machining
  • Super Alloy Hardened High Strength Steel Valve Seats
  • Manganese Silicon Bronze Valve Guides
  • Super Viton In Steel "Top Hat" Valve Seals
  • High Flow Necked Stainless Steel EV8 11/32" Valve Stems, Black Nitride Strength Treatment
  • Intake Valve 2.19" / Exhaust Valve 1.75"
  • Hardened Steel Rocker Arm Studs
  • 107cc Combustion Chambers
  • 315cc High Velocity Intake Port
  • 135cc High Velocity Exhaust Port
  • Complete 5 Angle Valve Job For Maximum Flow
vortec 8100 8.1L 496 performance cnc cylinder heads
CNC Extreme (400+ CFM) Cylinder Heads - $4295

We developed our CNC Extreme aluminum cylinder heads for large displacement and forced induction applications. If you are looking for maximum flow for your stroker engine, these heads are impossible to beat!

  • Lightweight A356T56 Alcoa Alloy Aluminum
  • Smooth Cast, 5 Axis CNC Centers Machining
  • Super Alloy Hardened High Strength Steel Valve Seats
  • Manganese Silicon Bronze Valve Guides
  • Super Viton In Steel "Top Hat" Valve Seals
  • High Flow Necked Stainless Steel EV8 11/32" Valve Stems, Black Nitride Strength Treatment
  • Intake Valve 2.25" / Exhaust Valve 1.88"
  • Hardened Steel Rocker Arm Studs
  • 107cc Combustion Chambers
  • 315cc High Velocity Intake Port
  • 135cc High Velocity Exhaust Port
  • Extensive 5 Axis CNC Porting
  • Complete 5 Angle Valve Job For Maximum Flow

The stock heads are JUNK with a capitol "J"! Don't even think about trying to step the stock heads up with port work. The castings are thin, the short side radius is way to high and the combustion chamber is a total joke. The stock version of these heads are the worst I have ever seen come out GM... Raylar cylinder heads take less timing, gain over 65 horsepower and improve gas mileage tremendously!! With the new intake manifold that Raylar designed the engine gets even more efficient. The stock cylinder heads were so bad that making them better was a snap. Better in every single regard, I might add.

Darrin Morgan, Reher Morrison Racing Engines



Cylinder Head FAQ

Big Power - A More Complete Burn

We've gone to great lengths to make improvements over the stock cast iron Vortec cylinder head. In the CAD image below, you can see just how much we've reshaped the combustion chamber in the Big Power cylinder head. Our combustion chambers promote a more even burn, increasing engine efficiency, fuel mileage, improving driveability and reducing detonation in forced induction applications.

raylar aluminum cnc cylinder head overlay vortec cylinder head

How Much Air Do Raylar Heads Flow?

Raylar big block Chevy / GMC cylinder heads out flow every 8.1L cylinder head on the market. Below are flow numbers for our standard Raylar CNC heads and our special-order CNC Extreme cylinder heads. We’ve included the Dart Iron Eagle 8.1L cylinder head in both 4.5 and 4.26 bores for comparison. Click on the image to see a larger version.

raylar aluminum cnc cylinder head flow