Condensation and your oil ( debate )
Thread Starter
TECH Enthusiast
Joined: Nov 2001
Posts: 712
Likes: 1
From: Dallas,Texas
Condensation and your oil ( debate ) I run a 160F thermostat.
Found this on the net ( below ) and find it intresting but
not for my setup ( I change oil 1500-1900 miles )
My next thought; Running around town with AC on
my coolant temp runs 200-205. I can turn off ac
and the temp will head for 220 unless I turn on
some fans.
I agree there problably is a small bit of condensation
in the motor. It seems to me that the filter would
catch it and the coating of oil from the last run would
in some way prevent it.
Snake Oil Elixir # 2: The 170 Degree Thermostat. $69.95: Claim, "lower engine temperature = more HP and greater engine life". My
Opinion: "BS." Anyone need a translation of that one? Fact: the LS1 engine develops its best, dyno proven HP and Torque at 195 - 210 degree
operating temperatures. Fact: water vapor (condensation) in your oil is an enemy to the durability of your engine? and condensation is
inevitable in any situation where metal goes from hot to cold (whenever you turn the key to the "Off" position). There are two ways to remove
condensation from you oil: 1. Change it; 2. Get the oil temperature to a level where any water in the oil will boil off as steam, be drawn into the
combustion process through your LS1?s PCV system, and exit the engine as water vapor out the exhaust pipe. To do this "boil off", the oil
temperature needs to get to 230 degrees. 212 degrees is not high enough as the crankcase operates under pressure. So, to encourage getting
the oil up to a "boil off temperature" to provoke this important oil decontamination process let?s remove the factory 190 degree thermostat,
and replace it with a 170?smart! OK, check the scorecard? no dyno proven HP gain at lower coolant temperatures, and adverse affects on the
oil quality by allowing condensation to build up in the oil circulating through your engine.
Anybody have a technical opinion on this..
Regards
Terry
Found this on the net ( below ) and find it intresting but
not for my setup ( I change oil 1500-1900 miles )
My next thought; Running around town with AC on
my coolant temp runs 200-205. I can turn off ac
and the temp will head for 220 unless I turn on
some fans.
I agree there problably is a small bit of condensation
in the motor. It seems to me that the filter would
catch it and the coating of oil from the last run would
in some way prevent it.
Snake Oil Elixir # 2: The 170 Degree Thermostat. $69.95: Claim, "lower engine temperature = more HP and greater engine life". My
Opinion: "BS." Anyone need a translation of that one? Fact: the LS1 engine develops its best, dyno proven HP and Torque at 195 - 210 degree
operating temperatures. Fact: water vapor (condensation) in your oil is an enemy to the durability of your engine? and condensation is
inevitable in any situation where metal goes from hot to cold (whenever you turn the key to the "Off" position). There are two ways to remove
condensation from you oil: 1. Change it; 2. Get the oil temperature to a level where any water in the oil will boil off as steam, be drawn into the
combustion process through your LS1?s PCV system, and exit the engine as water vapor out the exhaust pipe. To do this "boil off", the oil
temperature needs to get to 230 degrees. 212 degrees is not high enough as the crankcase operates under pressure. So, to encourage getting
the oil up to a "boil off temperature" to provoke this important oil decontamination process let?s remove the factory 190 degree thermostat,
and replace it with a 170?smart! OK, check the scorecard? no dyno proven HP gain at lower coolant temperatures, and adverse affects on the
oil quality by allowing condensation to build up in the oil circulating through your engine.
Anybody have a technical opinion on this..
Regards
Terry
Launching!
Joined: May 2002
Posts: 203
Likes: 0
From: Podunk, VA
Re: Condensation and your oil ( debate ) Excellent observation sir. Yes, the stock cooling works the way it does for a reason. But you cant tell alot other people that on here. Thanks for sharing your empirical data.
TECH Senior Member
Joined: Nov 2001
Posts: 7,234
Likes: 1
From: Mississauga, Ontario
Re: Condensation and your oil ( debate ) Oil does not have to get up to 230F in order to burn off the moisture. As a matter of fact, even when an oil temperature gauge reads 200F, there are some areas where your oil is getting much hotter than this. So in fact even if your oil doesn't hit 230F, you will have moisture burning off.
With a colder thermostat, you do run the risk of the oil not getting quite hot enough in the colder months to burn off the moisture completely though, especially on shorter trips. But in the hot summer, you will definitely not have a problem, especially if you get stuck in traffic a lot, where the oil temps will climb.
So my personal advice is to keep using the colder thermostats for the 70F and hotter temps, but once it starts getting regularily below that temp in your area, go back to the stock thermo. You don't need a colder temp in the cold weather anyways, since the chances of detonation are way less at 70F and under than when it's 100F outside. As a matter of fact, I run 89 octane in my LT1 in the winter, and have done scan tool testing which shows I get almost no spark retard at all.
With a colder thermostat, you do run the risk of the oil not getting quite hot enough in the colder months to burn off the moisture completely though, especially on shorter trips. But in the hot summer, you will definitely not have a problem, especially if you get stuck in traffic a lot, where the oil temps will climb.
So my personal advice is to keep using the colder thermostats for the 70F and hotter temps, but once it starts getting regularily below that temp in your area, go back to the stock thermo. You don't need a colder temp in the cold weather anyways, since the chances of detonation are way less at 70F and under than when it's 100F outside. As a matter of fact, I run 89 octane in my LT1 in the winter, and have done scan tool testing which shows I get almost no spark retard at all.
Re: Condensation and your oil ( debate ) I think we need to look at two different scenarios.
Scenario 1: The car has detonation problems in the upper rpm range, for whatever reason. A 160 thermostat is used to lower the immediate cylinder temperature and reduce detonation. The reduction in detonation allows the timing to be advanced. The HP gained by advancing the timing and avoiding KR is more than the HP losses incurred by removing excess heat from combustion.
Scenario 2: The car has NO detonation problems at all. Lowering the coolant temperature takes excess heat away from combustion and there is actually a HP loss.
IMHO detonation is a problem that is going to do far more damage to your engine than simple condensation. If your car is running fine up top without KR problems, then yes, I agree that there is no need to lower the coolant temperature. Many of our cars though suffer from KR problems up top (for whatever reason) though so the thermostat is actually a benificial mod for most of us.
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Scenario 1: The car has detonation problems in the upper rpm range, for whatever reason. A 160 thermostat is used to lower the immediate cylinder temperature and reduce detonation. The reduction in detonation allows the timing to be advanced. The HP gained by advancing the timing and avoiding KR is more than the HP losses incurred by removing excess heat from combustion.
Scenario 2: The car has NO detonation problems at all. Lowering the coolant temperature takes excess heat away from combustion and there is actually a HP loss.
IMHO detonation is a problem that is going to do far more damage to your engine than simple condensation. If your car is running fine up top without KR problems, then yes, I agree that there is no need to lower the coolant temperature. Many of our cars though suffer from KR problems up top (for whatever reason) though so the thermostat is actually a benificial mod for most of us.
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
