I'm sure that "not" was intended. However it took me some headscratching to see how that would affect pressure buildup, as vapor pressure of coolant would be constant at a given temperature -- until I realized that there are two different mechanisms involved. Initial pressure results from straight expansion of liquid coolant against the confines of the cooling system. Sixteen liters of 50% glycol coolant expands about half a liter going from 30C to 100C. Any air in the system would have a lower "spring rate" than the hoses, and would thus reduce the overall pressure -- until boiling, micro or otherwise, began; at which point the ultimate pressure would be controlled by the temperature in the hottest submerged section of the system, as vapor would be generated (quickly or slowly) until the equilibrium pressure was reached and the boiling stopped. All heat-generating portions of the system must be submerged to avoid severe local heating, as steam has greatly inferior heat transfer ability compared to liquid. Same problem with micro boiling, it interposes a low-conductivity layer between the heat source and coolant. Yrs, d On Sun, May 21, 2017 at 11:45 AM, George Gaudette <gcgaudette@gmail.com> wrote: > Can someone say a few more words about this?: > > "If the engine is completely filled with coolant the system will not build > pressure and micro boiling and vaporizing will do damage to the cylinder > walls and head studs" > > I'm thinking the word "not" might have been accidentally left out ("If the > engine is **not** filled..."). If so, not further explanation requested. > > -George > |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.