Engine wear versus coolant temperature

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1,183
Location
Vermont
Thought I would do a search on the WWW since I changed out the OE rating thermostat last summer thinking it might help while I was towing. Now that colder temps have arrived, I noticed my guage staying low. With short trips becoming common, I pondered (and did) reinstalling the OE stat. Yes I already changed out the 10yr old radiator, and figure the pump is next. I flushed the system in both directions before the change over. The thermostats operate just fine as ffar as I can tell, though I'm wondering about the OE temp guage as a few have reported on another board with this car. Check the link out. The graph looks interesting, though I'm not sure the parameters of the test other than rated cylinder wear and the maintained coolant temp. http://www.carnut.com/ramblin/cool3.html What does one think the wear is mostly attributed to - oil viscosiy, additive activation temperature, thermal expansion (improper part fitment)? Just curious as usual.
 
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1,418
Location
Sarasota, Florida
Oils are matched to engines at operating temperature. Thinner oils are tolerated better than oils that are too thick. This data shows again that wear is mostly a start up phenomenon. aehaas
 

Curious Kid

Thread starter
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1,183
Location
Vermont
The dramatic thinning processes of lubricating oil that occurs in warm-up seems more than just coincidience, of some similarity with the graph shown in the link, which is of some greater multiple. I think there's more at play than just viscosity however. [I dont know] Blow-by, incomplete combustion yielding fuel wash and then condensate. The dynamics seem facinating. I wonder if an auxilary lubrication spray could be added to the fuel-air intake uppon warm-up only, to further minimize this phenomina. Incomplete combustion propably would remain an issue as will the blow-by contaminents. Over the top probably, but that's an imagination for you. Another site I came across reported testing was being done with having rotating cylinder liners, that like having rotating cam tappets/lifter, wear was reduced. In the case of the cylinder liner, combustion pressures were reported higher as a better seal was being maintained by the rings - better lubrication sustainment. It's amazing what's going on under the hood!
 
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855
Location
India
At 45C outside temps, if my needle stays at 80C steady or creeps to max of 85C, I am happy, both my vehicles have oil coolers installed.
 
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9,448
Location
USA
This has been discussed in the past at length. Toyota and Lubrizol have authored papers for the SAE on this topic. Toyota found that ring wear was greatly influenced by coolant temp especialy with high sulphur fuels. Once the coolant temp. was up to normal the ring wear feel off sharply. Toyota used radioactive isotobes(sp)in the rings to track the rate of wear. I do not have access to SAE paper any longer and do not remember the number but it is available online. Another thing to consider is that usualy when someone install's a cooler thermostat in a vechile deposits increase.
 
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43,660
Location
'Stralia
Anyone who has pulled apart a 1970's vintage Holden straight 6 knows (whether they know it or not) about coolant temperature and wear. No.1 cylinder has a huge lip at the top of the bore, while No.6 is usually lip free. Difference ? No.1 is bathed in cold coolant, while number 6 runs in coolant heated by the first 5.
 
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441
Location
LA
Of course this makes sense, cold engines have a tighter piston/cylinder clearance. As the engine warms up, metals expand, the engine block having more mass expands faster than the piston, thus at operating temperature an engine expands to its normal clearances and it is good to go. Why do you think we have discussed so many times here as to why people should not redline an engine before it is fully warmed up? Why do all the different car racing sports have a warm-up lap?
 
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1,871
Location
.
quote:
Originally posted by kgb007stb : Of course this makes sense, cold engines have a tighter piston/cylinder clearance. As the engine warms up, metals expand, the engine block having more mass expands faster than the piston, thus .....
WHAT? [Eek!] [Roll Eyes]
 
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2,439
Location
Frankfort, Kentucky
Not being blessed with the intelligence of the other people here, or the ability to see the link, I would suggest going back to the stock T-stat for winter, and then thinking about using the lower t-stat for summer, or consider getting a stock t-stat and drilling a small hole in it. A lot of Grand Prix guys do this to overcome a funky fan setting that exists in the vehicle.
 
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9,448
Location
USA
Run the stock temp. thermostate unless you have exstenvice modified the engine. If the engine has not been reflashed then stock temp. is best. If you want to upgrade your T-Stat put a failsafe T-Stat in! If it fails you will not over heat. Why would any race team run a thermostat? Last time I raced wich was a long time ago a plate with a 3/8 inch hole I think was used in place of a thermostat. A plate with a hole in it can not fail!
 
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