Plain water cools better (that is, it transfers heat from the engine to the air better) so long as it is liquid. However, the temperature of the head is above the boiling point of water quite often in the summer, so the water boils and steam transfers MUCH less heat than water -- roasted head.
The glycol raises the boiling point considerably, so does the 20 psi pressure capacity of the cooling system, allowing the coolant to stay liquid and do it's job properly. Plain water will also permit electrolytic corrosion of the aluminum parts, and with no protection, it doesn't take long for it to eat large holes in aluminum parts. Peter -----Original Message----- >From: LarryT <[EMAIL PROTECTED]> >Sent: May 29, 2007 9:57 AM >To: Mercedes Discussion List <mercedes@okiebenz.com> >Subject: Re: [MBZ] 190E overheats > >Zoltan wrote:<<was told long ago that straight water cools better than >antifreeze.>> > >Check out http://autorepair.about.com/cs/coolingsystem/a/aa081101a.htm >which has this table - > > Water 50:50 70:30 AF/Water >Freezing point - 32F -35F -67F >Boiling Point 212F 223F 235F > >As you can see, adding water provides additional protection. Pressurizing >also helps. > >Larry T (67 MGB, 74 911, 78 240D, 91 300D) > >www.youroil.net for Oil Analysis and Weber Parts >Test Results http://members.rennlist.com/oil >PORSCHE POSTERS! youroil.net >Weber Carb Info http://members.rennlist.com/webercarbs >Porsche Road Test http://members.rennlist.com/roadtest/ >. >----- Original Message ----- >From: "Zoltan Finks" <[EMAIL PROTECTED]> >To: "Mercedes Discussion List" <mercedes@okiebenz.com> >Sent: Tuesday, May 29, 2007 4:33 AM >Subject: Re: [MBZ] 190E overheats > > >>I was told long ago that straight water cools better than antifreeze. >> >> Of course this option is dismal for long term. Growing up in AZ, you run >> into a lot of cars that have straight water in them. Coolant leaks are >> common, and when you don't need freeze protection, straight water is a >> very >> convenient option. Cars so treated also have the corresponding rust in the >> system. I think this is what caused us to have to purchase a replacement >> engine for our then newly-purchased 240D. >> >> Brian >> >> >> On 5/28/07, Peter Frederick <[EMAIL PROTECTED]> wrote: >>> >>> Better boil-over protection at 75%, but you get reduced cooling >>> capacity. Cadillac used to use 75% glycol for high temperature summer >>> (tropical) applications. Better freeze protection, too. >>> >>> Peter >>> >>> >>> _______________________________________ >>> http://www.okiebenz.com >>> For new parts see official list sponsor: http://www.buymbparts.com/ >>> For used parts email [EMAIL PROTECTED] >>> >>> To Unsubscribe or change delivery options go to: >>> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >>> >> _______________________________________ >> http://www.okiebenz.com >> For new parts see official list sponsor: http://www.buymbparts.com/ >> For used parts email [EMAIL PROTECTED] >> >> To Unsubscribe or change delivery options go to: >> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG Free Edition. >> Version: 7.5.472 / Virus Database: 269.8.0/821 - Release Date: 5/27/2007 >> 3:05 PM >> >> > > >_______________________________________ >http://www.okiebenz.com >For new parts see official list sponsor: http://www.buymbparts.com/ >For used parts email [EMAIL PROTECTED] > >To Unsubscribe or change delivery options go to: >http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
