Viscosity vs. Cooling Capacity vs. Corrosion (long) - Saab 9-5 Bulletin Board - Saabnet.com
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
4/9 Saab Owners' Convention Day Pass Raffle |
3/26 M Car Covers (by State of Nine)
[General |
Members |
C900 |
9000 |
NG900 & OG93 |
93 |
95 |
NG95 |
99 |
Sonett |
Vintage Models |
Clubs |
Other Cars |
FAQs |
Gifts |
Member Photo Galleries |
Member Directory |
Classifieds |
Manuals |
*Buddy Registry |
*Mileage Registry |
Polls |
What's New |
Raffle |
Photo of the Month |
Sponsors]
[Main 95 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Viscosity vs. Cooling Capacity vs. Corrosion (long)
Posted by Stephen Goldberger [Email] (more from Stephen Goldberger) on Sat, 16 Aug 2014 07:09:34
In Reply to: mixtures, saabsince 93b [Profile/Gallery]
, Fri, 15 Aug 2014 19:14:42
Members do not see ads below this line. - Help Keep This Site Online - Signup
Higher percentages of glycol result in higher viscosity, for less flow through the engine, and result in a lower specific heat in the mixture. That means the engine might run hotter, depending on the amount of excess cooling capacity in the cooling system. OTOH, the higher concentration of inhibitor and lower conductivity in the system (glycol is like an oil that is soluble in water and hence has lower conductivity)means less corrosion. The higher boiling point of a 70/30 mixture can result in less chance of nucleate boiling in the head, which can cause what's called "erosion corrosion" and which is suspected by some (including a boiling heat transfer specialist from Babcock in Wilcox in the 1970s) as the cause of "B motor" heads cracking (something which he had the dubious "opportunity" to examine first hand). But that's not something the 16 valve motor is known for.
There is the trade off from a technical perspective.
Digression: Me, I always used 2/3 to 1/3 glycol to water before the 9-5, primarily for less corrosion, used "American" style coolant, and changed every single year. My '91 9000 was the only one of the bunch that tended to run hot, which I cured by replacing the 180/200 fan switch (located at the coldest part of the radiator) with a 160/180 unit that Audi specified. Note that the 9000 had a 180 thermostat. I suspected that Saab spec'ed the fan switch to make sure the thermostat was always full open from May to October, thus extending its life. In '02 I had the opportunity to tour the GM Desert Proving Grounds near Phoenix. The test drivers told us that when they first received Saabs, there were a lot of overheating problems.
posted by 104.139.90...
Posts in this Thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
StateOfNine.com
|
SaabClub.com
|
Jak Stoll Performance
|
M Car Covers
|
Ad Available
|
Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!