When I was a younger man, I had Driven my '50 chevy from Los Angeles to
Chicago in the winter time. I had only water in the radiator. When I
arrived in Chicago I drained the radiator thinking it would also drain the
block, WRONG!! The block did not eject the freeze plugs, the block cracked.
It was a beautiful car, I junked it. Pat
-----Original Message-----
From: Marc Sayer <marcsayer@home.com>
To: karl.payne@gm.com <karl.payne@gm.com>
Cc: Fred_Katz@ci.sf.ca.us <Fred_Katz@ci.sf.ca.us>;
datsun-roadsters@autox.team.net <datsun-roadsters@autox.team.net>
Date: Monday, June 11, 2001 6:31 PM
Subject: Re: Steel core (not freeze) plugs
>Amen to this, the term freeze plugs is so misleading, though I still prefer
>brass. I think the big question for the car makers is cost. I have seen
only
>three modes of plug failure, seepage, pop out, and rust out. Seepage shows
up
>right away (if a plug starts seeping years later its a rust issue which is
>different) and is a fitment issue not a plug materials issue. Pop out is
not
>exactly plug materials related either. But rust out is completely materials
>related and happens to all steel plugs, zinc plated or not. Besides the
brass
>plugs look much cooler. :-)
>
>karl.payne@gm.com wrote:
>>
>> Amigos,
>> I would have to agree with steel core plugs. My experience in Mfg.
Engineering
>> at Ford and GM says steel is more durable and dimensionally stable than
brass.
>> The corrosion concern is solved by the zinc plating on the plug. This is
why we
>> don't use brass plugs for production engines. Steel is cheaper too.
; - ) And
>> we always apply anaerobic Loctite to the hole prior to pressing the
plugs in
>> place.
>> And now for my pet peeve: The PURPOSE of the large core holes is not to
protect
>> the engine in case the coolant freezes as is commonly believed. There
are two
>> reasons for these holes: 1. To allow the sand cores to be supported
during the
>> casting process. (They "float" in molten iron and shift around, therefore
they
>> must be secured)
>> 2. To provide exit ports for casting sand. After the casting is
solidified,
>> and the resin binder in the sand core has burned up, the castings go
through a
>> "shakeout" line where pneumatic hammers pound the *bleep* out of them and
the
>> sand pours out the holes. Without these holes they could never get all
the core
>> sand out and our radiators would be very unhappy. Not to mention heater
cores.
>>
>> BTW, in the majority of cases when the engine freezes, the "freeze
plugs" don't
>> pop out anyway.
>>
>> Just my $0.02.
>>
>> Karl Payne
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