Thermostat temps - don't mess around

[jim green]

Run the factory thermostat temperature. Your thermostat was designed by GM
engineers to maintain a minimum running temperature. They calculated the
total expansion of the pistons, rings, rods, bearings and like that. Most
notable is that before you have reached running temp, your pistons have a
tendancy to rock in the bore, since they haven't expanded completely to
their designed size. As they rock, they wear heavily on the lower portion of
the skirt and wear the cylinder bore to a taper (this is bad). Additionally
the rings break away from their sealing edge allowing blow-by gasses to
contaminate your oil. As the rings move inward and outward due to this
rocking they wear the ring lands wider and eventually a step is formed. This
reduces the gas loading of the rings which again contaminates your oil, and
as you mentioned reduces fuel economy and power. The oil temp was also
calculated, which must reach a temp high enough to boil off the moisture
(condensate) to reduce sludging. Additives help but here temp is a major
factor....I could go on but you get my point. Make it run cooler yes but,
don't drop T-stat temp to do it.
JGreen - a Ford guy w/ '73 Desert

> -----Original Message-----
> From: owner-gmcmotorhome
> [mailtowner-gmcmotorhome]On Behalf Of David L.
> Greenberg
> Sent: Friday, July 31, 1998 6:21 PM
> To: gmcmotorhome
> Subject: GMC: Thermostat temps
>
>
> At the risk of inciting mayhem I gotta tell ya, I switched to a 165f
> thermostat and my analog water temp gage runs a lower temp than when I
> had a 195f thermostat. Am I trading off something I don't yet know about?
>
> I have noticed my annual economy dropped off last year by about 15% but I
> attributed that to my engine getting tired (at 286k miles)!
>
> What else is the lower thermo costing me?
>
> Jump in!
>
> Dave Greenberg
> GMC Motorhome Registry
> 200 MacFarlane Dr
> Delray Beach, FL 33483-6829
> 1977 Eleganza II
>
> _____________________________________________________________________
> You don't need to buy Internet access to use free Internet e-mail.
> Get completely free e-mail from Juno at http://www.juno.com
> Or call Juno at (800) 654-JUNO [654-5866]
>

 

[thomas g. warner]

Jim, how do you make an engine run cooler without changing the thermostat?

>Run the factory thermostat temperature. Your thermostat was designed by GM
>engineers to maintain a minimum running temperature. They calculated the
>total expansion of the pistons, rings, rods, bearings and like that. Most
>notable is that before you have reached running temp, your pistons have a
>tendancy to rock in the bore, since they haven't expanded completely to
>their designed size. As they rock, they wear heavily on the lower portion of
>the skirt and wear the cylinder bore to a taper (this is bad). Additionally
>the rings break away from their sealing edge allowing blow-by gasses to
>contaminate your oil. As the rings move inward and outward due to this
>rocking they wear the ring lands wider and eventually a step is formed. This
>reduces the gas loading of the rings which again contaminates your oil, and
>as you mentioned reduces fuel economy and power. The oil temp was also
>calculated, which must reach a temp high enough to boil off the moisture
>(condensate) to reduce sludging. Additives help but here temp is a major
>factor....I could go on but you get my point. Make it run cooler yes but,
>don't drop T-stat temp to do it.
>JGreen - a Ford guy w/ '73 Desert
>
>> -----Original Message-----
>> From: owner-gmcmotorhome
>> [mailtowner-gmcmotorhome]On Behalf Of David L.
>> Greenberg
>> Sent: Friday, July 31, 1998 6:21 PM
>> To: gmcmotorhome
>> Subject: GMC: Thermostat temps
>>
>>
>> At the risk of inciting mayhem I gotta tell ya, I switched to a 165f
>> thermostat and my analog water temp gage runs a lower temp than when I
>> had a 195f thermostat. Am I trading off something I don't yet know about?
>>
>> I have noticed my annual economy dropped off last year by about 15% but I
>> attributed that to my engine getting tired (at 286k miles)!
>>
>> What else is the lower thermo costing me?
>>
>> Jump in!
>>
>> Dave Greenberg
>> GMC Motorhome Registry
>> 200 MacFarlane Dr
>> Delray Beach, FL 33483-6829
>> 1977 Eleganza II
>>
>> _____________________________________________________________________
>> You don't need to buy Internet access to use free Internet e-mail.
>> Get completely free e-mail from Juno at http://www.juno.com
>> Or call Juno at (800) 654-JUNO [654-5866]
>>
>
>
>
>

 

[jrbiava]

Answer with a question...can an engine run hotter even if the thermostat is
wide open?
Can an engine run cooler than before after increasing air intake and exhaust
ability, with more air thus more complete combustion and quicker and more
complete exhaust results in cooler overall operating temperatures.
- -----Original Message-----
From: Thomas G. Warner
To: gmcmotorhome
Date: Saturday, August 08, 1998 9:09 PM
Subject: RE: GMC: Thermostat temps - don't mess around

>Jim, how do you make an engine run cooler without changing the thermostat?
>
>
>

>>Run the factory thermostat temperature. Your thermostat was designed by GM
>>engineers to maintain a minimum running temperature. They calculated the
>>total expansion of the pistons, rings, rods, bearings and like that. Most
>>notable is that before you have reached running temp, your pistons have a
>>tendancy to rock in the bore, since they haven't expanded completely to
>>their designed size. As they rock, they wear heavily on the lower portion
of
>>the skirt and wear the cylinder bore to a taper (this is bad).
Additionally
>>the rings break away from their sealing edge allowing blow-by gasses to
>>contaminate your oil. As the rings move inward and outward due to this
>>rocking they wear the ring lands wider and eventually a step is formed.
This
>>reduces the gas loading of the rings which again contaminates your oil,
and
>>as you mentioned reduces fuel economy and power. The oil temp was also
>>calculated, which must reach a temp high enough to boil off the moisture
>>(condensate) to reduce sludging. Additives help but here temp is a major
>>factor....I could go on but you get my point. Make it run cooler yes but,
>>don't drop T-stat temp to do it.
>>JGreen - a Ford guy w/ '73 Desert
>>
>>> -----Original Message-----
>>> From: owner-gmcmotorhome
>>> [mailtowner-gmcmotorhome]On Behalf Of David L.
>>> Greenberg
>>> Sent: Friday, July 31, 1998 6:21 PM
>>> To: gmcmotorhome
>>> Subject: GMC: Thermostat temps
>>>
>>>
>>> At the risk of inciting mayhem I gotta tell ya, I switched to a 165f
>>> thermostat and my analog water temp gage runs a lower temp than when I
>>> had a 195f thermostat. Am I trading off something I don't yet know
about?
>>>
>>> I have noticed my annual economy dropped off last year by about 15% but
I
>>> attributed that to my engine getting tired (at 286k miles)!
>>>
>>> What else is the lower thermo costing me?
>>>
>>> Jump in!
>>>
>>> Dave Greenberg
>>> GMC Motorhome Registry
>>> 200 MacFarlane Dr
>>> Delray Beach, FL 33483-6829
>>> 1977 Eleganza II
>>>
>>> _____________________________________________________________________
>>> You don't need to buy Internet access to use free Internet e-mail.
>>> Get completely free e-mail from Juno at http://www.juno.com
>>> Or call Juno at (800) 654-JUNO [654-5866]
>>>
>>
>>
>>
>>
>

 

[jim green]

Thomas,
Cooler running temperatures can be achieved by reducing combustion
temperature with more efficient volumetric efficiency. Now we are talking
big bucks, however. Port matching, ported heads, polished chambers, manifold
change overs, polishing the block in the oil flow areas, all this will help,
but will cost you big time $$. For me I'd install a couple of additional oil
coolers, one for the trans & one for the engine. Let the thermostat work for
you. I would advise against bypassing your factory coolers since they help
to get you up to running temp ASAP. I'd have your radiator rodded out if you
are running hotter than you'd like. You can check it easily by running your
hand over the fins of the radiator (easier said than done) looking for cool
spots (cool = no flow) especially near the bottom. I'd look for air flow
restrictions thru the radiator, bent fins & bug deflectors or screens cause
problems on many vehicles by diverting or restricting the air flow. If your
condenser or add on coolers are too far or too close to the radiator they
will disrupt air flow by causing turbulence through the fins. Look for short
cuts the air can take around or under the radiator. Make sure your system is
holding pressure. An 8# cap adds 24 degrees (8X3=24) to 212 boiling + 10%
for 50/50 antifreeze brings your boiling temp to about 259 degrees
(212+24=236+23=259) My coach had 100% antifreeze, that's a no no. Coolant is
too thick(viscous), it has to be mixed with 1/2 water to gain cooling
qualities.
When are you running hot, idle(cooling system),under light load (air flow),
heavy load (timing/trans & all the above.)

> -----Original Message-----
> From: owner-gmcmotorhome
> [mailtowner-gmcmotorhome]On Behalf Of Thomas G.
> Warner
> Sent: Saturday, August 08, 1998 11:09 PM
> To: gmcmotorhome
> Subject: RE: GMC: Thermostat temps - don't mess around
>
>
> Jim, how do you make an engine run cooler without changing the thermostat?
>
>
>

> >Run the factory thermostat temperature. Your thermostat was
> designed by GM
> >engineers to maintain a minimum running temperature. They calculated the
> >total expansion of the pistons, rings, rods, bearings and like that. Most
> >notable is that before you have reached running temp, your pistons have a
> >tendancy to rock in the bore, since they haven't expanded completely to
> >their designed size. As they rock, they wear heavily on the
> lower portion of
> >the skirt and wear the cylinder bore to a taper (this is bad).
> Additionally
> >the rings break away from their sealing edge allowing blow-by gasses to
> >contaminate your oil. As the rings move inward and outward due to this
> >rocking they wear the ring lands wider and eventually a step is
> formed. This
> >reduces the gas loading of the rings which again contaminates
> your oil, and
> >as you mentioned reduces fuel economy and power. The oil temp was also
> >calculated, which must reach a temp high enough to boil off the moisture
> >(condensate) to reduce sludging. Additives help but here temp is a major
> >factor....I could go on but you get my point. Make it run cooler yes but,
> >don't drop T-stat temp to do it.
> >JGreen - a Ford guy w/ '73 Desert
> >
> >> -----Original Message-----
> >> From: owner-gmcmotorhome
> >> [mailtowner-gmcmotorhome]On Behalf Of David L.
> >> Greenberg
> >> Sent: Friday, July 31, 1998 6:21 PM
> >> To: gmcmotorhome
> >> Subject: GMC: Thermostat temps
> >>
> >>
> >> At the risk of inciting mayhem I gotta tell ya, I switched to a 165f
> >> thermostat and my analog water temp gage runs a lower temp than when I
> >> had a 195f thermostat. Am I trading off something I don't yet
> know about?
> >>
> >> I have noticed my annual economy dropped off last year by
> about 15% but I
> >> attributed that to my engine getting tired (at 286k miles)!
> >>
> >> What else is the lower thermo costing me?
> >>
> >> Jump in!
> >>
> >> Dave Greenberg
> >> GMC Motorhome Registry
> >> 200 MacFarlane Dr
> >> Delray Beach, FL 33483-6829
> >> 1977 Eleganza II
> >>
> >> _____________________________________________________________________
> >> You don't need to buy Internet access to use free Internet e-mail.
> >> Get completely free e-mail from Juno at http://www.juno.com
> >> Or call Juno at (800) 654-JUNO [654-5866]
> >>
> >
> >
> >
> >
>

 

[thomas g. warner]

Engine can run hotter even if thermostat is wide open for a number of
reasons. One is if the radiator has insufticient core capacity to dissipate
the heat from the coolant.

If the thermostat is working correctly the block cannot run cooler than the
thermostat setting, ie; 196 degrees etc. "more air thus more complete
combustion and quicker and more complete exhaust results in cooler overall
operating temperatures" is an incorrect statement and does not result in
cooler overall operating temperatures. It can impact efficiency however.

>Answer with a question...can an engine run hotter even if the thermostat is
>wide open?
>Can an engine run cooler than before after increasing air intake and exhaust
>ability, with more air thus more complete combustion and quicker and more
>complete exhaust results in cooler overall operating temperatures.
>-----Original Message-----
>From: Thomas G. Warner
>To: gmcmotorhome
>Date: Saturday, August 08, 1998 9:09 PM
>Subject: RE: GMC: Thermostat temps - don't mess around
>
>
>>Jim, how do you make an engine run cooler without changing the thermostat?
>>
>>
>>

>>>Run the factory thermostat temperature. Your thermostat was designed by GM
>>>engineers to maintain a minimum running temperature. They calculated the
>>>total expansion of the pistons, rings, rods, bearings and like that. Most
>>>notable is that before you have reached running temp, your pistons have a
>>>tendancy to rock in the bore, since they haven't expanded completely to
>>>their designed size. As they rock, they wear heavily on the lower portion
>of
>>>the skirt and wear the cylinder bore to a taper (this is bad).
>Additionally
>>>the rings break away from their sealing edge allowing blow-by gasses to
>>>contaminate your oil. As the rings move inward and outward due to this
>>>rocking they wear the ring lands wider and eventually a step is formed.
>This
>>>reduces the gas loading of the rings which again contaminates your oil,
>and
>>>as you mentioned reduces fuel economy and power. The oil temp was also
>>>calculated, which must reach a temp high enough to boil off the moisture
>>>(condensate) to reduce sludging. Additives help but here temp is a major
>>>factor....I could go on but you get my point. Make it run cooler yes but,
>>>don't drop T-stat temp to do it.
>>>JGreen - a Ford guy w/ '73 Desert
>>>
>>>> -----Original Message-----
>>>> From: owner-gmcmotorhome
>>>> [mailtowner-gmcmotorhome]On Behalf Of David L.
>>>> Greenberg
>>>> Sent: Friday, July 31, 1998 6:21 PM
>>>> To: gmcmotorhome
>>>> Subject: GMC: Thermostat temps
>>>>
>>>>
>>>> At the risk of inciting mayhem I gotta tell ya, I switched to a 165f
>>>> thermostat and my analog water temp gage runs a lower temp than when I
>>>> had a 195f thermostat. Am I trading off something I don't yet know
>about?
>>>>
>>>> I have noticed my annual economy dropped off last year by about 15% but
>I
>>>> attributed that to my engine getting tired (at 286k miles)!
>>>>
>>>> What else is the lower thermo costing me?
>>>>
>>>> Jump in!
>>>>
>>>> Dave Greenberg
>>>> GMC Motorhome Registry
>>>> 200 MacFarlane Dr
>>>> Delray Beach, FL 33483-6829
>>>> 1977 Eleganza II
>>>>
>>>> _____________________________________________________________________
>>>> You don't need to buy Internet access to use free Internet e-mail.
>>>> Get completely free e-mail from Juno at http://www.juno.com
>>>> Or call Juno at (800) 654-JUNO [654-5866]
>>>>
>>>
>>>
>>>
>>>
>>
>
>
>
>
>

 

[thomas g. warner]

Jim I have to respectfully disagree with part of your explanation. Porting
etc impacts the efficiency of the engine and can if properly done increase
the volume of gas flowing into the combustion chamber and exhaust gases out
of the engine, and thus increase horsepower. Net result is that more
gasoline mixture is packed into the chamber. Porting etc does not change the
temperature that the block runs at. For all intents and purposes the
thermostat determines the block temperature.

>Thomas,
>Cooler running temperatures can be achieved by reducing combustion
>temperature with more efficient volumetric efficiency. Now we are talking
>big bucks, however. Port matching, ported heads, polished chambers, manifold
>change overs, polishing the block in the oil flow areas, all this will help,
>but will cost you big time $$. For me I'd install a couple of additional oil
>coolers, one for the trans & one for the engine. Let the thermostat work for
>you. I would advise against bypassing your factory coolers since they help
>to get you up to running temp ASAP. I'd have your radiator rodded out if you
>are running hotter than you'd like. You can check it easily by running your
>hand over the fins of the radiator (easier said than done) looking for cool
>spots (cool = no flow) especially near the bottom. I'd look for air flow
>restrictions thru the radiator, bent fins & bug deflectors or screens cause
>problems on many vehicles by diverting or restricting the air flow. If your
>condenser or add on coolers are too far or too close to the radiator they
>will disrupt air flow by causing turbulence through the fins. Look for short
>cuts the air can take around or under the radiator. Make sure your system is
>holding pressure. An 8# cap adds 24 degrees (8X3=24) to 212 boiling + 10%
>for 50/50 antifreeze brings your boiling temp to about 259 degrees
>(212+24=236+23=259) My coach had 100% antifreeze, that's a no no. Coolant is
>too thick(viscous), it has to be mixed with 1/2 water to gain cooling
>qualities.
>When are you running hot, idle(cooling system),under light load (air flow),
>heavy load (timing/trans & all the above.)
>
>> -----Original Message-----
>> From: owner-gmcmotorhome
>> [mailtowner-gmcmotorhome]On Behalf Of Thomas G.
>> Warner
>> Sent: Saturday, August 08, 1998 11:09 PM
>> To: gmcmotorhome
>> Subject: RE: GMC: Thermostat temps - don't mess around
>>
>>
>> Jim, how do you make an engine run cooler without changing the thermostat?
>>
>>
>>

>> >Run the factory thermostat temperature. Your thermostat was
>> designed by GM
>> >engineers to maintain a minimum running temperature. They calculated the
>> >total expansion of the pistons, rings, rods, bearings and like that. Most
>> >notable is that before you have reached running temp, your pistons have a
>> >tendancy to rock in the bore, since they haven't expanded completely to
>> >their designed size. As they rock, they wear heavily on the
>> lower portion of
>> >the skirt and wear the cylinder bore to a taper (this is bad).
>> Additionally
>> >the rings break away from their sealing edge allowing blow-by gasses to
>> >contaminate your oil. As the rings move inward and outward due to this
>> >rocking they wear the ring lands wider and eventually a step is
>> formed. This
>> >reduces the gas loading of the rings which again contaminates
>> your oil, and
>> >as you mentioned reduces fuel economy and power. The oil temp was also
>> >calculated, which must reach a temp high enough to boil off the moisture
>> >(condensate) to reduce sludging. Additives help but here temp is a major
>> >factor....I could go on but you get my point. Make it run cooler yes but,
>> >don't drop T-stat temp to do it.
>> >JGreen - a Ford guy w/ '73 Desert
>> >
>> >> -----Original Message-----
>> >> From: owner-gmcmotorhome
>> >> [mailtowner-gmcmotorhome]On Behalf Of David L.
>> >> Greenberg
>> >> Sent: Friday, July 31, 1998 6:21 PM
>> >> To: gmcmotorhome
>> >> Subject: GMC: Thermostat temps
>> >>
>> >>
>> >> At the risk of inciting mayhem I gotta tell ya, I switched to a 165f
>> >> thermostat and my analog water temp gage runs a lower temp than when I
>> >> had a 195f thermostat. Am I trading off something I don't yet
>> know about?
>> >>
>> >> I have noticed my annual economy dropped off last year by
>> about 15% but I
>> >> attributed that to my engine getting tired (at 286k miles)!
>> >>
>> >> What else is the lower thermo costing me?
>> >>
>> >> Jump in!
>> >>
>> >> Dave Greenberg
>> >> GMC Motorhome Registry
>> >> 200 MacFarlane Dr
>> >> Delray Beach, FL 33483-6829
>> >> 1977 Eleganza II
>> >>
>> >> _____________________________________________________________________
>> >> You don't need to buy Internet access to use free Internet e-mail.
>> >> Get completely free e-mail from Juno at http://www.juno.com
>> >> Or call Juno at (800) 654-JUNO [654-5866]
>> >>
>> >
>> >
>> >
>> >
>>
>
>
>
>