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From: jeff@rtech.ARPA (Jeff Lichtman)
Newsgroups: net.auto,net.consumers
Subject: Re: No Leaded Gas -- Now What?
Message-ID: <231@rtech.ARPA>
Date: Mon, 11-Mar-85 15:23:34 EST
Article-I.D.: rtech.231
Posted: Mon Mar 11 15:23:34 1985
Date-Received: Thu, 14-Mar-85 03:43:20 EST
References: <252@hocsd.UUCP>
Organization: Relational Technology, Berkeley CA
Lines: 14
Xref: watmath net.auto:6073 net.consumers:1977

> I understand that new cars have special values which are hollow
> and filled with sodium? Does this help decrease combustion chamber
> temps?

The sodium inside such valves melts when it gets hot, and convects inside
the valve.  This convection helps cool the valve by carrying heat up the
stem where the valve can be cooled better.  This can help prevent knocking
(hot valves can cause the fuel to ignite prematurely).  It can also help
keep the valves from burning.  I don't think it would do much to solve the
lack of cushioning and lubrication in the valve seat caused by the lack
of lead.
-- 
Jeff Lichtman at rtech (Relational Technology, Inc.)
aka Swazoo Koolak