Goodson Tools and Supplies for Engine Rebuilders suggests using Carbide Pilots for precise and high-quality valve seat and bowl work.
1. Carbide pilots offer the following advantages:
- Carbide Pilots help keep tooling cutting true. When cutting 3-angle
seats, counterboring for seat rings or using Bowl Hogs to enlarge valve
bowls, the resistance of the workpiece against the tool tries to deflect
the pilot. Goodson Carbide Pilots resist this deflection five times
better to keep the tool cutting precisely in its path.
- Carbide Pilots are resistant to wear and maintain “like new”
precision. Carbide Pilots are much more resistant to wear than tool
steel pilots. As steel pilots wear, they lose their initial precision
and allow an increase in run-out with age. Carbide Pilots maintain their
greater precision many times longer. Their stability in use and
performance over a long period of time makes these pilots a greatly
- Creates the most concentric valve seat finish. The rigidity of the
carbide pilot (5 times less deflection) creates the concentric valve
seat finish available. Please note, however, that due to the brittle
nature of carbide, they must be handled with care!
Goodson’s carbide pilots have .375″ top-size and range from .157″
(3.99mm) to .379″ (9.626mm). PIlots are available in Serdi-style straight
(live) or conventionally tapered (dead).
2) Be sure to secure cylinder head.
Some shimming may be required to assure a more concentric seat and a
better finish. Make certain that the cylinder head is firmly attached to
the head fixture of the machine so that no vibrations can occur.
3) Keep tips sharp!
Remember that the tip (or formtool) should be kept sharp at all times.
DO NOT allow it to become dull. The sharper the tip, the less drag it
will have, thus reducing the chance for chattering.
Tech Tip courtesy of Goodson Tools & Supplies for Engine Rebuilders.