Battery will only produce 40% cranking power at 0 degrees.

Jeepjeepster · **Posted:** Sun Dec 13, 2009 1:40 pm

Just as a note. Heat does NOT rise in a solid like a gas or liquid. If you heat the oil pan the oil will be heated but the heat will not rise through the engine. It will heat the block some due to thermal conductivity but thats it.

Personally I think its much more important to keep the oil warm than it is the coolant. With the oil being warm it should keep the crank and pistons some what warm which is good. Just wont have heat in the cabin as quick as a block heater..

dieselenthusiast · **Posted:** Sun Dec 13, 2009 1:51 pm

Jeepjeepster wrote:

Just as a note. Heat does NOT rise in a solid like a gas or liquid. If you heat the oil pan the oil will be heated but the heat will not rise to through the engine. It will heat the block some due to thermal conductivity but thats it.

Q: How does a Pad Heaters do a better job of Heating the engine than block heaters or tank type heaters?
A: Pad Heaters put Heat into the oil supply. HEAT RISES to warm important INTERNAL components.

Q: Are the pistons included in the list of Heater INTERNAL components and if so what temperatures are they warmed to?
A: Pistons are generally warmed to 30°C (85°F) or so as governed by variables in engine type and design.

Q: Will a Pad Heaters raise an engines coolant temperature?
A: Remember HEAT RISES off the heated oil supply. The crankcase walls along with the cylinder wall, the outer block wall and
the coolant between them create a very effective barrier to the loss of heat to the atmosphere.
Only a small amount of Heat is absorbed by the coolant resulting in a 15-20° increase in coolant temperature.

http://www.padheaters.com/faq.html

CATCRD · **Posted:** Sun Dec 13, 2009 2:26 pm

The thing about a pad heater is that half of it is exposed to the air, so half your wattage is wasted. A heater screwed into the block gets all its wattage into the block.

dieselenthusiast · **Posted:** Sun Dec 13, 2009 2:46 pm

CATCRD wrote:

The thing about a pad heater is that half of it is exposed to the air, so half your wattage is wasted. A heater screwed into the block gets all its wattage into the block.

Q: How do Pad Heaters compare in use of electricity with old style coolant heaters?
A: Pad Heaters , application for application, use less energy than block or tank type coolant heaters. Pad Heaters are more economical to operate than block heaters. Compare watt ratings.

Q: How hot does the oil get?
A: Pad Heaters raise oil temperatures to approximate operating levels.

Q: How long does it take a Pad Heater to do it's Heating job?
A: Pad Heaters will generally raise cold oil temperatures by 38°C (100°F) in 1.5 - 2 hours. Full Heating is usually accomplished in 5-6 hours.

Q: Will a Pad Heater save me money?
A: YES, Pad Heaters will save you money by increasing engine and starter life. They are maintenance free and use much less electricity than a block heater.

Q: Are Pad Heaters available in other voltages?
A: Yes. There are heaters available in 120 & 220 volts A.C. and 12 & 24 volts D.C.

CATCRD · **Posted:** Sun Dec 13, 2009 3:54 pm

Ok, we get it. You keep posting the same marketing hype from the manufacturer. I'm posting facts from personal experience with both products.

Explain how what I posted above is not a major disadvantage of pad heaters.

Quote:

Q: Will a Pad Heater save me money?
A: YES, Pad Heaters will save you money by increasing engine and starter life. They are maintenance free and use much less electricity than a block heater.

This statement is silly. They use less electricity, so they DON'T WORK AS WELL. We're talking about a resistive heating element here - you can't claim that less = more.

rjmaype · **Posted:** Sun Dec 13, 2009 7:57 pm

I think for the same starting effect rather than a battery heating pad one could but a trickle battery charger on timer for an hour and regain the full capacity of the battery.

95BadBoy · **Posted:** Sun Dec 13, 2009 8:58 pm

rjmaype wrote:

I think for the same starting effect rather than a battery heating pad one could but a trickle battery charger on timer for an hour and regain the full capacity of the battery.

At -20 to -40F, I'll take a battery heater over a trickle charger. :wink:

The trickle charger just isn't going to have the same effect on a cold battery as a battery heater will.

Jeepjeepster · **Posted:** Sun Dec 13, 2009 9:19 pm

dieselenthusiast wrote:

Jeepjeepster wrote:

Just as a note. Heat does NOT rise in a solid like a gas or liquid. If you heat the oil pan the oil will be heated but the heat will not rise to through the engine. It will heat the block some due to thermal conductivity but thats it.

Q: How does a Pad Heaters do a better job of Heating the engine than block heaters or tank type heaters?
A: Pad Heaters put Heat into the oil supply. HEAT RISES to warm important INTERNAL components.

Q: Are the pistons included in the list of Heater INTERNAL components and if so what temperatures are they warmed to?
A: Pistons are generally warmed to 30°C (85°F) or so as governed by variables in engine type and design.

Q: Will a Pad Heaters raise an engines coolant temperature?
A: Remember HEAT RISES off the heated oil supply. The crankcase walls along with the cylinder wall, the outer block wall and
the coolant between them create a very effective barrier to the loss of heat to the atmosphere.
Only a small amount of Heat is absorbed by the coolant resulting in a 15-20° increase in coolant temperature.

http://www.padheaters.com/faq.html

Heat doesnt rise in a soild object..

tjkj2002 · **Posted:** Sun Dec 13, 2009 9:30 pm

Jeepjeepster wrote:

Heat doesnt rise in a soild object..

Actually is does,it also goes sideways and down also,it's called thermo conductivity.

dieselenthusiast · **Posted:** Sun Dec 13, 2009 10:06 pm

CATCRD wrote:

Ok, we get it. You keep posting the same marketing hype from the manufacturer. I'm posting facts from personal experience with both products.

Explain how what I posted above is not a major disadvantage of pad heaters.

Quote:

Q: Will a Pad Heater save me money?
A: YES, Pad Heaters will save you money by increasing engine and starter life. They are maintenance free and use much less electricity than a block heater.

This statement is silly. They use less electricity, so they DON'T WORK AS WELL. We're talking about a resistive heating element here - you can't claim that less = more.

CATCRD, you don’t like these heater pads do you? :lol:

I’m not trying to argue, but I am trying to let everyone know that these heater pads are definitely something to consider. Those who do use them seem to really like them. It might not be your cup of tea, but these heater pads seem to make a lot of sense for some of us.

kdlewis1975 · **Posted:** Mon Dec 14, 2009 12:06 am

I think the decision to use the heating pad depends on the goal.

If you want the engine to be "pre-warmed" then the block heater should be the way to go. The coolant is going to have a higher heat capacity than the oil and would give the better bang for the buck in terms of getting closer to operating temperature since it is in contact with more of the engine than the oil that's collected in the oil pan.

If you're worried about oil getting circulated through a cold engine more quickly, then heating the oil is a wonderful idea. The starter and battery have to work less. But in terms of having a warm engine, it's probably not going to be as good as the block heater.

Personally, I think the way to go would be to use the block heater and get a pad to put on the transmission pan. The engine would be pre-warmed and we should be able to get into overdrive sooner since we typically burn a lot of fuel just to heat the transmission fluid while driving after a cold-start.

I don't really buy the "heat rises, and therefore your engine gets warmed" on the heating pad site as well. The oil and pan will be nice and warm, but the heat transfer above the oil is going to be marginal. The air above it will get warmed and rise via convection, but the heat transfer to the engine parts is going to poor. Because the area of contact of the oil pan to the engine is relatively small, the amount of conduction through that to the block and the internal parts is going to be poor as well. It all depends on how efficiently and how much warm/hot oil can transfer heat to the engine.

Jeepjeepster · **Posted:** Mon Dec 14, 2009 1:56 am

tjkj2002 wrote:

Jeepjeepster wrote:

Heat doesnt rise in a soild object..

Actually is does,it also goes sideways and down also,it's called thermo conductivity.

Already covered that.. See my first post..

RJM · **Posted:** Mon Dec 14, 2009 6:20 am

This topic could not have come at a better time. yesterday was -47C here, I went to top off the the oil in the Jeep, turned the bottle upside down and ,wait,wait,wait There it is! thicker than the honey I put on my toasty bread this morning. I cannot help musing over the following questions:

1) What is the cost to operate the oil heater pan, factoring in thermal loss and extra power consumption as CATCRD highlighted? I dunno, and I don't care.
2) What is the cost of a new engine if I pork mine because it was started when the oil was thicker than seal snot? I dunno, and don't want to find out.
3) What is the cost of "peace of mind"? PRICELESS!
4) Why do I live here? Because the USA dosen't have Chezzies, Millhouse Creek Beer, Tim Hortons or Celine Dion (OK, you guys have her, please keep her there)
5) Why do I get involved in fruitless debates on this forum? Cuz it's to cold to go outside and plug in my Jeep.
This is turning into circular reasoning, just kiddin' about fruitless debates, in fact someone needs to play The Devils Advocate, otherwise we would all be using Amsoil and stickin' our CCV hoses up our buttcracks just cuz someone told us it was the best thing to do!

RJM · **Posted:** Mon Dec 14, 2009 6:32 am

PS. With the pan heater plugged in for 5 hours at -47C with no wind, the valve cover is warm to the touch. Does heat rise through the engine? Not in Harry Potters world, but in the real world it does!

RJM · **Posted:** Mon Dec 14, 2009 7:32 am

95BadBoy wrote:

rjmaype wrote:

I think for the same starting effect rather than a battery heating pad one could but a trickle battery charger on timer for an hour and regain the full capacity of the battery.

At -20 to -40F, I'll take a battery heater over a trickle charger. :wink:

The trickle charger just isn't going to have the same effect on a cold battery as a battery heater will.

Even a good battery at -40 for a sustained period will freeze and crack. I am looking at buying a Die hard Platinum right now to avoid this.

Jeepjeepster · **Posted:** Mon Dec 14, 2009 11:36 am

If the heater is 1,500 watts and your power company charges $0.15 per kw/hr(which is high) then it would cost around $.45 to run the heater for 2 hours.. If you have a timer and run it for 2 hours every morning for 30 days thats $14 a month..

And RJM, if youre living in the real world and not with Harry then yes, your vavle covers should be warm. See my post and tjkj's post.

RJM · **Posted:** Mon Dec 14, 2009 11:46 am

Jeepjeepster wrote:

Just as a note. Heat does NOT rise in a solid like a gas or liquid. If you heat the oil pan the oil will be heated but the heat will not rise to through the engine. It will heat the block some due to thermal conductivity but thats it.

Personally I think its much more important to keep the oil warm than it is the coolant. With the oil being warm it should keep the crank and pistons some what warm which is good. Just wont have heat in the cabin as quick as a block heater..

Perhaps you can translate this for me?

Jeepjeepster · **Posted:** Mon Dec 14, 2009 12:51 pm

RJM wrote:

Jeepjeepster wrote:

Just as a note. Heat does NOT rise in a solid like a gas or liquid. If you heat the oil pan the oil will be heated but the heat will not rise to through the engine. It will heat the block some due to thermal conductivity but thats it.

Personally I think its much more important to keep the oil warm than it is the coolant. With the oil being warm it should keep the crank and pistons some what warm which is good. Just wont have heat in the cabin as quick as a block heater..

Perhaps you can translate this for me?

Fixed it.. Didnt mean to cause this much attention.. On that website it says "remember, heat rises." I was just saying thats only true for a liquid and a gas. In a solid object, heat will radiate in all directions, not just up..

UFO · **Posted:** Mon Dec 14, 2009 12:51 pm

tjkj2002 wrote:

Jeepjeepster wrote:

Heat doesnt rise in a soild object..

Actually is does,it also goes sideways and down also,it's called thermo conductivity.

Convection heating DOES NOT occur in a solid. Fact. But you are correct that conduction does, and it's a combination of convection and conduction that transfers heat in an engine. All told though, coolant heating is by far the most effective. Oil pan heating, not so much.

dieselenthusiast · **Posted:** Sun Nov 28, 2010 8:47 pm

tjkj2002 wrote:

Be careful with those battery heaters,some years of KJ's have a battery temp sensor and it's located were that heater would go and will confuse the PCM which has the voltage regulator and may not recharge the battery at all.

Thanks Troy, I did some checking and found that there is only 1 battery sensor and its under the drivers battery. I'll stick with electric battery blankets on the Dodge since they won't effect the sensor nor the charge rate. The Mopar electric blanket on the KJ works great.

Battery will only produce 40% cranking power at 0 degrees.

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