160deg t-stat: bad for engine wear and making power?
12-08-2005, 09:52 PM
#1
160deg t-stat: bad for engine wear and making power? From Vinci High Performance web site:
"Proper Coolant Temperature and Camshaft Life!
Have you ever tried to find what proper coolant temperature is for most automotive engines? There are a lot of people who think they know, but it is difficult to find specifics, even in textbooks. We know we want the intake air to be as cold as possible (for best power) because cold air is denser (there are more oxygen atoms per cubic foot). The coolant temperature, however, is a different matter. The internal combustion engine changes chemical energy stored in gasoline into heat energy that is focused on the piston tops. If the cylinder heads and engine block are too cold, they will absorb much of the combustion heat before it can be used to push the piston down the cylinder. If the engine gets too hot, engine lubricants can break down, as well as overheating of the intake charge can lead to detonation, etc.
It turns out that coolant (usually a 50/50 mixture of coolant and water) has some fantastic properties that are ideal for use in engines. With a properly pressurized cooling system, coolant will not freeze until –30°F, and it won’t boil until +270°F (new oils don’t start to break down until well over 270°F). With these characteristics, engine designers have decided that engines should operate at approximately 210-215°F. Why, you ask? Well, it has to do with operating the engine at a high enough temperature to boil water out of the oil after the engine is cold started. If you have dew on the grass, it is certain that you have water in your oil, as the crankcase is open to atmospheric pressure! You can either remove the water by draining it out the bottom of the oil pan (remember the oil floats on water) or run the engine long enough and hot enough to boil the water out of the lubrication system. Years ago, coolants weren’t as sophisticated and engines were run at 165-180F, but the oil was changed every 1000 miles or so. That’s why many old timers think engines should run at 165-180F. Have you ever noticed that Ford doesn’t put temperature marks on their gauges? They just mark C for cold and H for hot and write “normal” through the center. If you hook up a scan tool to a GM, you will often find that the gauge reads much lower than the coolant temp sensor. That is because they know most drivers don’t understand how hot an engine should run.
So what does this have to do with camshafts? Many enthusiasts erroneously think that the colder their engine runs the better! If they are not running the engine hot enough to boil the water out of the oil, the oil becomes contaminated and the lifter/cam lobe interface is the highest load point in the engine. Engines running too cool can contribute significantly to camshaft and lifter failure. Think about it: What good does it do to use the most expensive synthetic oil and then run the engine so cold that it is contaminated by water vapor??!! Another point, piston manufacturers’ piston-to-wall clearance recommendations assume you will be running the fully warmed engine at 200°+F. Run the engine too cold, and you could see some scuffed pistons because the cylinders had not expanded enough to provide clearance.
If your engine will only run its best at the drag strip with the engine at 165°F, you probably have too cold of a spark plug heat range and you are probably jetted way too rich! If you keep the engine hot (not the intake charge), you will be using more of the heat energy in the gasoline to make power instead of just heating up your block. It does take “tuning know-how” to run an engine at 200-210°F, but you might be surprised how well and how long it runs when you do!! One final point - running a computer managed engine at 165°F compared to the factory 210°F will often cost you as much as 4 MPG. The reason for this is that the computer thinks that the engine is not off the “choke cycle” and it is still putting out a rich mixture! Check the science on this and don’t pay attention to the “old wives tales” of the past. Materials and lubricants are much better and different today than they were in the past!!"
http://www.vincihighperformance.com/fbodyls1.html
"Proper Coolant Temperature and Camshaft Life!
Have you ever tried to find what proper coolant temperature is for most automotive engines? There are a lot of people who think they know, but it is difficult to find specifics, even in textbooks. We know we want the intake air to be as cold as possible (for best power) because cold air is denser (there are more oxygen atoms per cubic foot). The coolant temperature, however, is a different matter. The internal combustion engine changes chemical energy stored in gasoline into heat energy that is focused on the piston tops. If the cylinder heads and engine block are too cold, they will absorb much of the combustion heat before it can be used to push the piston down the cylinder. If the engine gets too hot, engine lubricants can break down, as well as overheating of the intake charge can lead to detonation, etc.
It turns out that coolant (usually a 50/50 mixture of coolant and water) has some fantastic properties that are ideal for use in engines. With a properly pressurized cooling system, coolant will not freeze until –30°F, and it won’t boil until +270°F (new oils don’t start to break down until well over 270°F). With these characteristics, engine designers have decided that engines should operate at approximately 210-215°F. Why, you ask? Well, it has to do with operating the engine at a high enough temperature to boil water out of the oil after the engine is cold started. If you have dew on the grass, it is certain that you have water in your oil, as the crankcase is open to atmospheric pressure! You can either remove the water by draining it out the bottom of the oil pan (remember the oil floats on water) or run the engine long enough and hot enough to boil the water out of the lubrication system. Years ago, coolants weren’t as sophisticated and engines were run at 165-180F, but the oil was changed every 1000 miles or so. That’s why many old timers think engines should run at 165-180F. Have you ever noticed that Ford doesn’t put temperature marks on their gauges? They just mark C for cold and H for hot and write “normal” through the center. If you hook up a scan tool to a GM, you will often find that the gauge reads much lower than the coolant temp sensor. That is because they know most drivers don’t understand how hot an engine should run.
So what does this have to do with camshafts? Many enthusiasts erroneously think that the colder their engine runs the better! If they are not running the engine hot enough to boil the water out of the oil, the oil becomes contaminated and the lifter/cam lobe interface is the highest load point in the engine. Engines running too cool can contribute significantly to camshaft and lifter failure. Think about it: What good does it do to use the most expensive synthetic oil and then run the engine so cold that it is contaminated by water vapor??!! Another point, piston manufacturers’ piston-to-wall clearance recommendations assume you will be running the fully warmed engine at 200°+F. Run the engine too cold, and you could see some scuffed pistons because the cylinders had not expanded enough to provide clearance.
If your engine will only run its best at the drag strip with the engine at 165°F, you probably have too cold of a spark plug heat range and you are probably jetted way too rich! If you keep the engine hot (not the intake charge), you will be using more of the heat energy in the gasoline to make power instead of just heating up your block. It does take “tuning know-how” to run an engine at 200-210°F, but you might be surprised how well and how long it runs when you do!! One final point - running a computer managed engine at 165°F compared to the factory 210°F will often cost you as much as 4 MPG. The reason for this is that the computer thinks that the engine is not off the “choke cycle” and it is still putting out a rich mixture! Check the science on this and don’t pay attention to the “old wives tales” of the past. Materials and lubricants are much better and different today than they were in the past!!"
http://www.vincihighperformance.com/fbodyls1.html
12-08-2005, 11:29 PM
#2
That's all good and fine, but since when does a 160 stat cause your engine to run at 165? 160 is simply the range when the stat begins to open. Most will run somewhere around 185 with proper fan settings. A thermostat will have little effect on oil temp, and as long as you get the engine up to operating temps condensation is a non issue. I doubt you'll gain much power with a 160 stat, but it does help control detonation, and IMO is the main reason why you should run one.
12-08-2005, 11:52 PM
#4
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The only time I see a good 160degree thermostat actually helps an engine is when its summertime and it is constantly 85degrees+ outside.
But as of right now in West Texas, it is 35degrees during the day and I have place my stock thermostat back in to run hot.
But as of right now in West Texas, it is 35degrees during the day and I have place my stock thermostat back in to run hot.
12-08-2005, 11:56 PM
#5
Originally Posted by BackinBlack02SS
That's all good and fine, but since when does a 160 stat cause your engine to run at 165? 160 is simply the range when the stat begins to open. Most will run somewhere around 185 with proper fan settings. A thermostat will have little effect on oil temp, and as long as you get the engine up to operating temps condensation is a non issue. I doubt you'll gain much power with a 160 stat, but it does help control detonation, and IMO is the main reason why you should run one.
12-09-2005, 12:41 AM
#6
With a 160* Powerstat in my car, it consistently runs 180-195 degrees on the aftermarket gauge I have installed. I've scanned the car with Autotap and the gauge was only 1* off. It runs closer to 195 in the summer and 180 in the winter. Car makes the same gas mileage as it did stock, and this is with dying 02 sensors.
Fan settings are:
Fan 1 on 190 off 180
Fan 2 on 200 off 190
It's all about the fan settings. I also read somewhere that the Powerstat doesn't fully open until around 175*.
Fan settings are:
Fan 1 on 190 off 180
Fan 2 on 200 off 190
It's all about the fan settings. I also read somewhere that the Powerstat doesn't fully open until around 175*.
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12-09-2005, 04:01 AM
#8
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My car has a 160 tstat, and with hp tuner, we elimeinated, air,eger,cags and rear 02s, no real pcm tuning, but we did change the fan settings to 175 and 184 I believe, is this to cold, could I be running to rich, especially with long tubes, if so,I will raise the fan temps. any info is appreciated.I just don't wanna leave any horsepower on teh table.
12-09-2005, 08:17 AM
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Originally Posted by BackinBlack02SS
That's all good and fine, but since when does a 160 stat cause your engine to run at 165? 160 is simply the range when the stat begins to open. Most will run somewhere around 185 with proper fan settings. A thermostat will have little effect on oil temp, and as long as you get the engine up to operating temps condensation is a non issue. I doubt you'll gain much power with a 160 stat, but it does help control detonation, and IMO is the main reason why you should run one.
12-09-2005, 09:16 AM
#10
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Here's the deal. My "160" Hypertech 'stat opens
about 175F (light load ECT with full fans) and will
swing up to 179F (fmoderate power rolling fast).
But you need a lot of airflow with a skinny little
1-core aluminum radiator, to back this up. On a
long grade in summer with the A/C on, still see
200+ ECT.
The stock "184" produces a tighter, higher pivot
temp, about 194F ECT. Under bad air conditions
you will still be radiator limited. But the 'stat will
not let your temps swing under 194F.
The fans are the "wild card". Stock settings are
lame, pushing them down to at or below 'stat
pivot temp reduces the ECT range your tune has
to play against. You have to either set main spark
table, or more properly the ECT spark adder, to
make it not ping while maximizing power. The less
you vary ECT the tighter you can push the main
table or the less work you have to do with the
temp adder (big deal, do it).
Since the plastic manifold has little capacity to
throw heat, and the head passages are so short,
at higher velocities you are not going to put that
much heat into the intake charge. At lower RPM
you will see more heating and that is also where
your degrees of advance means more actual time,
in which to ping (ping being peak pressure before
TDC from a way-before-TDC spark, and charge
temp/pressure being a burn rate accelerator).
ECT is an average temp in the water jacket. Oil
is on the other side of the water jacket so most
likely won't get above ECT in the rocker valley.
Pistons are only oil cooled. Splash there will be
hotter and boil out any "riders". Top end oil and
pan oil, probably not. Neither 177 nor 194 will
truly boil water. Change your oil often.
I tuned my spark up for what the 160F 'stat
could tolerate and found a lot of ping once the
radiator capacity was overrun. Using a lower
temp 'stat will let you run more advance under
good conditions but no better than before,
under bad. You have to deal with that somehow.
I bought an LT1 radiator to throw on (one of
these days).
Whether you gain or lose max power from trading
efficiency (194F+) for density (177F+) you'd have
to either try, or take somebody's word for. With
stock setups I doubt there's a gain, I found none
even with tuning. However I prefer cooler for
reasons like hot-spot and heat surge margin.
The harder you push the engine output the more
heat you will throw to the water jacket and, 1/4
mile at a time, starting from a lower initial temp
will let you finish before you make steam pockets,
maybe. Especially as the 'stat reacts slower than
heat is spiked, and the fans even slower than
that.
Also on the "parts now, install someday" list is
moving to a tank-temp-controlled fans scheme.
I want reserve heat capacity such that the 'stat
has authority enough to squelch sudden loads,
not have to wait for the fans to play catch-up
(little gimps that they and the radiator are).
If you live up North in cold air then you probably
don't care, but on 100F+ pavement all 9 months
of summer, this stuff makes a big difference.
As a performance mod, in my book it's a waste
of money until you have built up to really expose
the cooling limitations of the system. It's no
substitute for sane fan temps. It is however a
low buck mod and a lot of people would rather
hang something on that they can afford today,
than wait for something more meaningful and
expensive.
Colder will let you tolerate more spark like the
tuning toys want to, and tools let you, push.
Whether this translates to more ultimate power
(not to be confused with "seat of the pants"
part throttle "responsiveness") is questionable,
you max out WOT power several degrees before
ping and there is "flat land" before that.
about 175F (light load ECT with full fans) and will
swing up to 179F (fmoderate power rolling fast).
But you need a lot of airflow with a skinny little
1-core aluminum radiator, to back this up. On a
long grade in summer with the A/C on, still see
200+ ECT.
The stock "184" produces a tighter, higher pivot
temp, about 194F ECT. Under bad air conditions
you will still be radiator limited. But the 'stat will
not let your temps swing under 194F.
The fans are the "wild card". Stock settings are
lame, pushing them down to at or below 'stat
pivot temp reduces the ECT range your tune has
to play against. You have to either set main spark
table, or more properly the ECT spark adder, to
make it not ping while maximizing power. The less
you vary ECT the tighter you can push the main
table or the less work you have to do with the
temp adder (big deal, do it).
Since the plastic manifold has little capacity to
throw heat, and the head passages are so short,
at higher velocities you are not going to put that
much heat into the intake charge. At lower RPM
you will see more heating and that is also where
your degrees of advance means more actual time,
in which to ping (ping being peak pressure before
TDC from a way-before-TDC spark, and charge
temp/pressure being a burn rate accelerator).
ECT is an average temp in the water jacket. Oil
is on the other side of the water jacket so most
likely won't get above ECT in the rocker valley.
Pistons are only oil cooled. Splash there will be
hotter and boil out any "riders". Top end oil and
pan oil, probably not. Neither 177 nor 194 will
truly boil water. Change your oil often.
I tuned my spark up for what the 160F 'stat
could tolerate and found a lot of ping once the
radiator capacity was overrun. Using a lower
temp 'stat will let you run more advance under
good conditions but no better than before,
under bad. You have to deal with that somehow.
I bought an LT1 radiator to throw on (one of
these days).
Whether you gain or lose max power from trading
efficiency (194F+) for density (177F+) you'd have
to either try, or take somebody's word for. With
stock setups I doubt there's a gain, I found none
even with tuning. However I prefer cooler for
reasons like hot-spot and heat surge margin.
The harder you push the engine output the more
heat you will throw to the water jacket and, 1/4
mile at a time, starting from a lower initial temp
will let you finish before you make steam pockets,
maybe. Especially as the 'stat reacts slower than
heat is spiked, and the fans even slower than
that.
Also on the "parts now, install someday" list is
moving to a tank-temp-controlled fans scheme.
I want reserve heat capacity such that the 'stat
has authority enough to squelch sudden loads,
not have to wait for the fans to play catch-up
(little gimps that they and the radiator are).
If you live up North in cold air then you probably
don't care, but on 100F+ pavement all 9 months
of summer, this stuff makes a big difference.
As a performance mod, in my book it's a waste
of money until you have built up to really expose
the cooling limitations of the system. It's no
substitute for sane fan temps. It is however a
low buck mod and a lot of people would rather
hang something on that they can afford today,
than wait for something more meaningful and
expensive.
Colder will let you tolerate more spark like the
tuning toys want to, and tools let you, push.
Whether this translates to more ultimate power
(not to be confused with "seat of the pants"
part throttle "responsiveness") is questionable,
you max out WOT power several degrees before
ping and there is "flat land" before that.
12-09-2005, 11:40 AM
#11
Thanks for chiming in, Jimmy. That's a lot to digest but it sounds like running a 160* stat properly requires a bit more effort than it's worth, at least for the slightly modified car.
And I get the impression that you believe the concerns over oil becoming contaminated with water due to lowered oil temps is valid. It makes sense since water boils at 212*F.
For reference on oil temp I came across a write up were a guy installed an oil cooler and his oil temp did drop below 200*F at times.
http://para.noid.org/oilcooler/
So I guess it is wise to change the motor oil more frequently if you run a cool stat.
I wonder about A/F ratio on these cool running cars.
And I get the impression that you believe the concerns over oil becoming contaminated with water due to lowered oil temps is valid. It makes sense since water boils at 212*F.
For reference on oil temp I came across a write up were a guy installed an oil cooler and his oil temp did drop below 200*F at times.
http://para.noid.org/oilcooler/
So I guess it is wise to change the motor oil more frequently if you run a cool stat.
I wonder about A/F ratio on these cool running cars.
12-09-2005, 04:14 PM
#13
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Originally Posted by BackinBlack02SS
That's all good and fine, but since when does a 160 stat cause your engine to run at 165? 160 is simply the range when the stat begins to open. Most will run somewhere around 185 with proper fan settings. A thermostat will have little effect on oil temp, and as long as you get the engine up to operating temps condensation is a non issue. I doubt you'll gain much power with a 160 stat, but it does help control detonation, and IMO is the main reason why you should run one.
Originally Posted by vinci tech
If your engine will only run its best at the drag strip with the engine at 165°F, you probably have too cold of a spark plug heat range and you are probably jetted way too rich!
12-09-2005, 05:06 PM
#15
Originally Posted by mrr23
read a little closer, nowhere does it say a 160* t-stat will run the car at 165*. what it says is this:
It also says, "One final point - running a computer managed engine at 165°F compared to the factory 210°F will often cost you as much as 4 MPG. The reason for this is that the computer thinks that the engine is not off the “choke cycle” and it is still putting out a rich mixture!"
The way it is written leads the reader to believe that a 160 stat will cause your engine to run at 165 degrees. Otherwise, why was a number like 165 thrown out there in the first place?
12-09-2005, 06:34 PM
#16
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I like the stock stat (or hypertech 180) best.
With fan programming, my temps cycle in the 190-205 range depending on outside temps.
After trying many temp ranges on my LS1s, I like that range best.
With fan programming, my temps cycle in the 190-205 range depending on outside temps.
After trying many temp ranges on my LS1s, I like that range best.
12-09-2005, 07:11 PM
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Up north I could see where that thinking would be correct, but with the weather down in texas ... I can't think of a single reason NOT to run a colder thermostat. Like others have said, its only the opening temp ... and my car usually runs ~195-200 in the summertime ... haven't had a chance to log anything now that its colder out ... but I doubt it's below 185.
12-10-2005, 02:13 AM
#20
So according to Vinci, a oil cooler would be worthless and a bad idea because it will cause premature cam and lifter wear? I have read about a few people running the LGM oil cooler setups, and they state their oil temp is a couple of degrees higher than their water temp. Would that be too cool to have your oil run?