Auto.trans. in neutral any cooling benefits?
#16
Rest in Peace
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If it is really cold, mine is going to warm up before i get in it, I can buy more gas and if I wear a engine out, well I built that one, I can do it again.
I asked about putting a block heater in mine when I was doing the build on it and got laughed at, wish I would have had one made now.
The big plugs in the back of the heads would be a good place for the heaters to go.
I asked about putting a block heater in mine when I was doing the build on it and got laughed at, wish I would have had one made now.
The big plugs in the back of the heads would be a good place for the heaters to go.
#19
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@ -35 the answer is easy...........dont shut them off and without a block heater after sitting outside all night you may as well stay inside...........its just brutal on any car/truck.
#21
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I think you have to throw out the human time factor here because the engine sees thing in RPM's. Driving may or may not warm it faster but if it does it does under some load. That load causes stresses and friction.
Idling at 1000 rpm's for 7 minutes vs. driving at 3500 RPM's for 2 minutes = both engines operating for 7000 total rpm's
Same RPM's seen by the engine, longer time seen by the human, while idling no load on engine, oil comes up to temp, coolant comes up, metals expand. Happy engine. Driving right away puts load on engine that is not up to temp. Same amount of fuel used as far as the washing but I have never had any smell in the oil and change it often enough.
Engines live by RPM's not the clock (or the odometer) I'll stick with idling. This might be a cross-drilled rotors type of discussion.
Idling at 1000 rpm's for 7 minutes vs. driving at 3500 RPM's for 2 minutes = both engines operating for 7000 total rpm's
Same RPM's seen by the engine, longer time seen by the human, while idling no load on engine, oil comes up to temp, coolant comes up, metals expand. Happy engine. Driving right away puts load on engine that is not up to temp. Same amount of fuel used as far as the washing but I have never had any smell in the oil and change it often enough.
Engines live by RPM's not the clock (or the odometer) I'll stick with idling. This might be a cross-drilled rotors type of discussion.
First, the human time factor is evident since on higher rpm water and oil is pumped faster - therefore, oil temperature is rpm sensitive (oil is getting faster warm when high revving, instead of water). Oil temp is the most important factor on engine wear. Only after reaching normal temp, the oil is thin enough to reach all bearings. Don't get that wrong - under very low temperatures even synthetic oils are thick and probably bypassing the bearings vie the blow-off valve.
Second, an engine under load is not only revving higher, but producing more and on different places heat, which decreases the warm-up time as well. In my studies I learned a rule that says 'on idle, an engine is getting hot head and cold feet', because the heads are getting on low rpm quickly warm whilst the block does not. So you'll have to struggle with different temperatures - not good. For example, pistons are expanding faster than the bores.
So we always taught drivers to drive asap and to not stress the engine by revving too high or too low, which means especially on manuals more often gear changing.
Btw: Do you know that an engine looses per 100k mls in average 120-150g metal (sleeves ca. 12-15g each, bearings about 20g and piston rings nearly two times of that). And its not the amount of total rpms, but the conditions under those is has done them as well.
Cheers
Marc
#22
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Grew up in Minneapolis. -40 (same in C or F) was not all that uncommon from time to time. Being the kid, my car was relegated to the outside. Needless to say, I had a block heater. Sometimes put a lightbulb under the car too to help keep the oil pan a bit warmer.
#23
Drifting
Sorry me, but that is not fully correct.
First, the human time factor is evident since on higher rpm water and oil is pumped faster - therefore, oil temperature is rpm sensitive (oil is getting faster warm when high revving, instead of water). Oil temp is the most important factor on engine wear. Only after reaching normal temp, the oil is thin enough to reach all bearings. Don't get that wrong - under very low temperatures even synthetic oils are thick and probably bypassing the bearings vie the blow-off valve.
Second, an engine under load is not only revving higher, but producing more and on different places heat, which decreases the warm-up time as well. In my studies I learned a rule that says 'on idle, an engine is getting hot head and cold feet', because the heads are getting on low rpm quickly warm whilst the block does not. So you'll have to struggle with different temperatures - not good. For example, pistons are expanding faster than the bores.
So we always taught drivers to drive asap and to not stress the engine by revving too high or too low, which means especially on manuals more often gear changing.
Btw: Do you know that an engine looses per 100k mls in average 120-150g metal (sleeves ca. 12-15g each, bearings about 20g and piston rings nearly two times of that). And its not the amount of total rpms, but the conditions under those is has done them as well.
Cheers
Marc
First, the human time factor is evident since on higher rpm water and oil is pumped faster - therefore, oil temperature is rpm sensitive (oil is getting faster warm when high revving, instead of water). Oil temp is the most important factor on engine wear. Only after reaching normal temp, the oil is thin enough to reach all bearings. Don't get that wrong - under very low temperatures even synthetic oils are thick and probably bypassing the bearings vie the blow-off valve.
Second, an engine under load is not only revving higher, but producing more and on different places heat, which decreases the warm-up time as well. In my studies I learned a rule that says 'on idle, an engine is getting hot head and cold feet', because the heads are getting on low rpm quickly warm whilst the block does not. So you'll have to struggle with different temperatures - not good. For example, pistons are expanding faster than the bores.
So we always taught drivers to drive asap and to not stress the engine by revving too high or too low, which means especially on manuals more often gear changing.
Btw: Do you know that an engine looses per 100k mls in average 120-150g metal (sleeves ca. 12-15g each, bearings about 20g and piston rings nearly two times of that). And its not the amount of total rpms, but the conditions under those is has done them as well.
Cheers
Marc
This is interesting. The 2 sources of heat in an engine are the fire/explosion of combustion in the chamber and the friction of the piston against the cylinder wall. So I agree that different areas are heating up before others. But these areas are surrounded by the water/coolant passages whereas the oil is further away in the sump. In fact the 928 keeps the water/coolant in the block until it reaches operating temp.
Circulating cold fluids does not heat them so is of no benefit.
some info I have found in my search so far on this;
After driving in a friend's RS with an oil temp guage, I was amazed at how long it actually did take for the oil to get up to operating temp.
However, for those with Subaru's water-to-oil oil coolers, the coolant will actually act as a heater, helping the oil to get up to temp quicker.
Just remember that your oil warms up slower than your coolant
FWIW, I was always under the impression that it was OK to "get on it" once the temp guage reached it's normal operating temp spot. Totally not the case. I remember seeing his temp guage in the operating temp spot but his oil temp guage barely moved yet!!!
This is the best evidence yet F1 engineers warming up a cold F1 engine staring at the computer info
They only idle it for minutes before slightly revving with ZERO load and look at the computer screen
Coolant 83 degrees
Oil 39 degrees
No oil pressure _ I think on that alone it is safe to say that driving off before coolant has reached operating temp is going to expose the engine to excess wear because oil warms up 2nd and is no where near capable of reaching/protecting areas while still cold!
http://www.youtube.com/watch?v=xd9jk99J1C0
Last edited by tv; 08-10-2011 at 10:38 AM.
#24
Drifting
I wonder if people who are building dry sump systems have aux oil heaters, in that case I would say idling to warm up would not be so important.
But for our engines warming up with no load while idling is the way I am going to go and having a good engine oil that leaves a protective film on parts. (this applies only to cold engines after sitting overnight or days not on multiple starts in one day.)
But for our engines warming up with no load while idling is the way I am going to go and having a good engine oil that leaves a protective film on parts. (this applies only to cold engines after sitting overnight or days not on multiple starts in one day.)
#25
Shameful Thread Killer
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I have had Dodge tow vehicles for years. Always put the trans in neutral as often as I can to reduce pressure on the valve bodies and from the TC. My current tow Durango has 235k on it and has towed some really big ****. No trans problems. Oh, also added a cooler in front when I bought it at 55k miles. Helps a lot.
As for warming the engine, from the aviation world(all air cooled engines). If unable to preheat the engine, best to preheat the oil with a hot stick in place of the dip stick. All small aircraft have an oil temp gauge and it does have a yellow arc below about 35F. We start cold aircraft engines and leave them at low idle until the oil is at least 35F, and typically closer to 50F before moving off. By the time we do all our pre-takeoff checks, and taxi to the runway, it's ready for full throttle ops. I would not move a car until the oil is above 20F for multi-vis. That means idling for a while, which also allows the water in the block to come up to operating temp before cycling except for the bypass hose(small circulation).
As for warming the engine, from the aviation world(all air cooled engines). If unable to preheat the engine, best to preheat the oil with a hot stick in place of the dip stick. All small aircraft have an oil temp gauge and it does have a yellow arc below about 35F. We start cold aircraft engines and leave them at low idle until the oil is at least 35F, and typically closer to 50F before moving off. By the time we do all our pre-takeoff checks, and taxi to the runway, it's ready for full throttle ops. I would not move a car until the oil is above 20F for multi-vis. That means idling for a while, which also allows the water in the block to come up to operating temp before cycling except for the bypass hose(small circulation).
#26
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Interesting Doc.
I also haul and tow heavy loads with my 3/4 ton duramax. It has a Alison auto tranny and as its a HD model came factory equipped with a large tranny oil cooler and a temp guage. Never had an issue and will monitor temps in gear and neutral when idling (not often here but I'll try to remember).
I too take time to allow for warm up before moving.........the truck because I drive it in all conditions, the 928 because I care. Checking route, flight path, getting the right tunes set, pulling on the d.gloves all give ample time
I also haul and tow heavy loads with my 3/4 ton duramax. It has a Alison auto tranny and as its a HD model came factory equipped with a large tranny oil cooler and a temp guage. Never had an issue and will monitor temps in gear and neutral when idling (not often here but I'll try to remember).
I too take time to allow for warm up before moving.........the truck because I drive it in all conditions, the 928 because I care. Checking route, flight path, getting the right tunes set, pulling on the d.gloves all give ample time
#27
Rennlist Member
idle at lights, and then anticipate the green to get it in gear just before you have to take off.
coast up to lights. easier on brakes, smoother stops and waste less gas.
I do it, but Anderson thinks im from Planet Zenon when I do it with him in the car.
coast up to lights. easier on brakes, smoother stops and waste less gas.
I do it, but Anderson thinks im from Planet Zenon when I do it with him in the car.
#29
Pro
Weird. Everyone in Bangkok, Thailand does that when they come to a stop in traffic. I always wondered why. Now I know
#30
Rennlist Member
I like when in Japan, same thing, but they also turn off their headlights when not moving in traffic, or at a light. so polite on the street, and angry on the race track those drivers on that side of the planet!