Ferrari Mailing List: Re: Why a 308GT4?.......sodium valves

(continued)

At 01:17 PM 5/17/2007 +1000, Peter Pless wrote:
"Why do sodium cooled exhaust valves fail?"

  Molten sodium + wrong steel alloy = failure.
  Molten sodium is a very corrosive substance.
  Further the slightest trace of moisture inside
  the stem at filling results in Na0H forming which
  is also corrosive and H2 gas, which causes Hydrogen
  embrittlement of the steel.
  In essence, sodium filled valves are a great idea
  when executed PERFECTLY and a very bad idea otherwise.
  Jim

Re: Why a 308GT4?.......sodium valves	<– Date –> <– Thread –>
From: Jim Conforti (lndshrkxmission.com)
Date: Wed, 16 May 2007 22:53:53 -0700 (PDT)