The Anatomy of a Valve Seat Cutter Blade

Valve Seat Cutter Blade DiagramEvery multi-angle Valve Seat Cutter Blade has two essential measurements and three essential angles. Top Width, Seat Width, Main Angle, Top Angle and Throat Angle. Of course, as the blades become more complex there will be additional angles, measurements, radii ... you name it.

We don't have the room to cover all of the theory behind the angles and how they create air flow in this article, but you can find some great stuff out on the internet if you search. Keep in mind, though, that not everyone knows what they're talking about. Get your information from a reliable source.

Valve SeatValve Seat Cutter Blade Terms

Top Angle: usually 30°, this is the angle on the combustion side of the seat angle 

Seat Angle: usually 45°, this is the angle at which the seat and the valve face mate to produce a gas-tight seal

Throat Angle: generally 60°, this is the bottom angle which transitions airflow from the seat angle to the port.

These terms correspond to the parts of the seat and valve too.

The 2019 Goodson catalog lists 117 stock Valve Seat Cutter Blades (see pages 6 to 9). You'd think that would just about cover it, but we have requests for custom cutters almost every day. Find out more about ordering Custom Valve Seat Cutter blades on our Custom Cutter Page.

At Goodson you'll find several blade categories:

  • Mondello Signature Series Cutter Blades
  • Radius Profile Cutter Blades
  • 3-D Three-Angle Cutter Blades (30º and 45º Seat Angles)
  • Single Angle Cutter Blades
  • Black Smoke Series Cutters for High Performance Diesel Engines
  • Micro Cutter Blades and Mini Cutter Blades

We're going to take a short look at each one of these so keep on reading. But, before we do, here's a couple of quick tips.

  1. Cutters with straight, precise angles with no blending between the angles are generally used for intake
  2. Cutters with radius profiles or blended angles are generally used for exhaust

Sampling of Mondello Signature Series Valve Seat Cutter BladesMondello Signature Series Cutter Blades

These Valve Seat Cutter Blades were designed for Goodson by industry legend, Joe Mondello. They are designed to increase airflow by as much as 20 CFM. When they were designed Joe intended them for specific applications but we've found over time that sometimes what is labeled as an intake cutter is just what you need for your exhaust set-up. 

Experiment to find the right blade to produce the flow and horsepower you need. Check out the full assortment here. If you need some help choosing the right blade, be sure to call the Goodson Techxperts™.

IFT-HP-SET3 Pc. High Performance Valve Seat Cutter Set

A year or so back we created a 3 Piece Set Seat Cutters designed to increase flow and improve horsepower on just about every head. Check it out here.

Radius Profile Seat Cutter Blades

These cutter blades sport some interesting shapes, radii and angles to give you lot of options for increasing air flow in your valve seats. A lot of research, development and experimentation has gone into these profiles to duplicate the angles found in aftermarket heads. Each head manufacturer has a development team that has put together a set of specs for each of its offerings and you need cutters that will maintain those specs or you could lose flow and power. 

Goodson offers a variety of Radius Profile Cutter Blades for High Performance, Light Duty Diesels, Harley-Davidson, etc.

Page 8 of the 2018 Goodson Catalog3-D Three-Angle Seat Cutter Blades

These are basic cutters that have been developed over the years to work on stock heads. As we said before, every manufacturer has their own specifications and these cutters have been designed to fit those specs. Generally you will find these with either a 45º or 30º Seat Angle but that's where the similarities end. From here, you have a range of throat angles, seat widths and top widths to choose from. View the complete selection of Valve Seat Cutter Blades.

Single Angle Valve Seat Cutter Blades

As the name implies, these seat cutter blades have a single angle instead of multiple angles and radii. Goodson stocks cutters with angles from 15º to 94º. These cutters give you the option of customizing a single angle on a seat.

Black Smoke Series Seat Cutter BladesDiesel Valve Seat Cutter Blades

Goodson actually offers a couple of types of Seat Cutter Blades for Diesel applications. First are the standard 3-angle cutters, with a few variations and tweaks of course. Next are the Black Smoke Series Cutters for High Performance Diesel Engines. 

The Black Smoke Series Cutters were developed for Goodson by Joe Mondello Racing Engines for specific applications (see illustration at left). 

Diesel Relief Tool Working PhotoTo go along with these cutters, Mondello Racing Engines developed a Diesel Relief Tool that will increase high lift air flow, increase torque and increase horsepower in high performance diesel engines. For more information, check out the how to video at the bottom of the product page.

Last, but not least, we come to the 

Micro & Mini Valve Seat Cutter Blades

As the name implies, they are small size cutter blades. The Micro Cutters were developed to work with Goodson's 3-D Fast Cut Micro-Ball Head Tooling and are available in several profiles. Mini Cutters are designed to fit the Mini Cutter Holders Goodson introduced to fit Sunnen® and Mira® ball heads for brazed cutters. 

As always, if you have additional questions, feel free to contact the Goodson Techxperts by email or phone (1-800-533-8010).

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