Hood blanket... literally? (engine compartment thermal insulation)

[theunchosen]

just seal off the engine bay at the hood grill and put a belly pan on... all of those improve aero as well and are much cheaper than anything thats going to survive block insulation. line your hood, firewall and interior of the grill with aluminum to add insulation rather than just sealing gaps. might as well coat the belyy pan too. insulating the block itself would mandate taking it apart if the temperatures even get into the 50s otherwise your going to cook the engine. Might look at adding a bypass loop in the radiator for a large thermos to reroute coolant until the engine gets warm.

[basslover911]

Well with sealing the whole engine compartment I'm thinking that everything will retain a lot of heat, which is not always optimal. By everything I mean EVERYTHING, the battery (def not good if that gets really hot), all of the wiring and electronics, etc.

That's why I kind of wanted to isolate the engine from not only the air around it but also from all of the electrical components, radiator, and battery... just a thought correct me if im wrong...

I mean it would be though A LOT easier to seal the whole compartment, im just scared for those components mentioned above...

[theunchosen]

Even if you... sealed off the engine bay as thoroughly as the uber-aero mods on here. In the winter there is going to be enough air flowing in through various places to keep the bay from actually getting warm.

What you want is for the engine bay to remain removed from the heat exchange while its parked. The hood "blanket" idea is beneficial if you're going to drive and then park it and drive it again within 1-2 hours.

Otherwise its not going to be very helpful. You can't completely seal up either the engine bay or the engine itself. Doing either of those is going to cause the ICE to overheat at any temperature above freezing, at which point your rad fans kick on and start sucking more juice than you were losing through heat exchange out of the block.

If you want the car to passively(without block heating) warm up quicker I can't remember who it was that suggested it but they had the idea of putting a thermos in parrallel with their radiator and a valve and then choosing which the pumps used. So when the engine is cold you use the thermos so you can cycle the coolant through the system to get it all warm get the block warm and then shift it to the radiator to keep the engine in operating temperatures. sealing the hood and putting heat reflective components will help keep the engine warmer on the go... but a slight breeze in winter temps can provide a very very large heat sink.

[user removed]

04-09 Prius had a thermos to hold hot water for quick warm ups on restarts.

Saw one from a damaged car at my friends body shop. $1000 in parts to replace it. Held a decent amount of heat for 4 days in freezing temps.

Heat retention in the winter as well as preheating the coolant before initial starts would go a long way to achieving summertime mileage in wintertime.

There are other factors such as higher atmospheric density that cause winter temperatures to reduce mileage, but a significant amount of the difference could be eliminated if you could duplicate summertime conditions as far as fast warm ups, higher engine compartment temperatures and hotter coolant coming out of the radiator to the engine.

Also warmer air is a duplication of summertime temperatures and increases mileage, especially when compared to extreme cold temperatures experienced in northern climates.

All of these modifications in total have the same effect as normal summertime operating temperatures. Coolant exiting the radiator in summer is close to 120degrees fahrenheit compared to 60 degrees in wintertime, even lower when temps go lower than freezing.

We all know that with winter coming we will see a significant drop in mileage, at least for those who have significantly colder winters.

I used to do a quick check for radiator effectiveness by simply holding my hand on the top and bottom hoses. At 180 degrees I could hold my hand on the top hose for about 5 seconds. In winter the bottom hose was always much colder than the top hose as long as the radiator was doing it's job.

Remember, every cooling system is designed to handle the most extreme of situations, 100 degrees pulling a load up a steep incline, with the Ac blasting away which in many cars preheats the air before it gets to the radiator itself.

In arctic climates I would be it would be possible to hypermile a car with the radiator completely disconnected using only the heater core to keep the engine cool.

I always like the idea of a thermostat that was in the return circuit that mixed bypassed (uncooled) coolant with coolant going through the radiator to maintain the 120 degree temperature of the coolant entering the engine.

This would mean automatic ambient temperature compensation regardless of outside temperatures.

regards
Mech

[MetroMPG]

Sorry if this has already come up in this thread, but:

BMW has been experimenting with fully encapsulating the engine with insulating materials to preserve heat to minimize the number of truly "cold" starts:

To keep temperatures within the engine compartment at a high level for as long as possible and to avoid having to warm up the engine from the regular ambient temperature, the engine is fully encapsulated. In addition to the air flaps behind the BMW kidney grille already introduced in 2007 in the context of BMW EfficientDynamics, an engine on a prototype that is already developed is completely surrounded by fully clad walls and panels, the engineers using proven materials from the underfloor of the car for insulation purposes.

With encapsulation, an engine running at a temperature of 80 °C or 176 °F cools down much more slowly after being switched off and still has a temperature of approximately 40 °C or 104 °F after 12 hours.

With each degree of temperature having a significant influence on fuel consumption, this improvement alone provided by encapsulation reduces fuel consumption by up to 0.2% for each extra degree of temperature (in °C).

This method of maintaining temperatures is equally suited for all kinds of vehicles and in all climate zones, although it is somewhat more effective at low temperatures. Highly efficient dampening of heat on the drivetrain also has some positive side effects.

Source: Green Car Congress: BMW Outlines Intelligent Heat Management Applications for Reducing Fuel Consumption and CO2; New Thermoelectric Generator Unit Integrated with EGR

[Frank Lee]

Ha! They finally caught up to me!

http://ecomodder.com/forum/showthrea...-em-10529.html

[basslover911]

EXACTLY what I want to do... so what material should I use?

[bgd73]

Originally Posted by Sean T.

I know that most hoods have a "blanket" under them to insulate the engine compartment... I plan on getting a second one just to beef up the insulation.

I have been thinking... would it be worth it to get a large blanket or quilt and bungee it to the hood of the car when I run into the store or something, to keep the car warm if I am going to be more than 10 minutes? Or even to leave on my car while I am in class...

The theory seems to be good, but practicality might be difficult because if it snows, then I am stuck with a snow covered blanket to clean off and fold back into the trunk...

Anybody have any comments or thoughts???

as hoods a have a pattern of openings in the subframing, .25 inch fire proof insulation, it has a silever lining both sides, foam type stuff, somewhat rigid..is an oe type good idea, to fit right in, maybe even crumple it up and get a few openings at the same time.. I can't remember the name of that stuff...it gets mentioned once and awhile. I want to do that for a very cold running boxer, tiny carbed. forever warming up.
flammable or old GM type fiber stuff is ridiculous. I remeber a 78 delta 88 with a very large one (big hood). It was very quiet, and it conquered a physic, but it needed all snow removed completely, it never melted.

[PaleMelanesian]

Originally Posted by basslover911

Hi! Im sorry to bring back a little old thread BUT...

Can you put the "peel and seal" tape directly on the engine block? I want to somehow make a blanket directly on the engine block but need something that can resist the heat (probably 180 degrees or so)... I think this is the MOST effective way of keeping heat in, by directly going to the engine block instead of the hood

Originally Posted by shovel

It'll fall off, the adhesive gets soft at high temps.

Warning - Do not use Peel & Seal in the engine bay! It gets so soft, it falls off. Mine was on the underside of the hood. It actually dripped some of the asphalt backing onto the exhaust pipes - major smoking going on.

[Rokeby]

Another thread discussing engine/engine bay insulation:

http://ecomodder.com/forum/showthrea...gine-6359.html

This link in thread shows a tight-fitting, custom made engine "cozy"
in the Engine Blanket section. Temps under the cover are monitored in
multiple locations. Very neat, very difficult, very expensive I bet.

Randall's Insight - MIMA Honda Insight Modified Integrated Motor Assist