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Just another crazy idea I thought I would pick people's brain about.

Most of what I have read on line seems to focus on adding energy in with block heaters and such in order to get a cars engine up to a better running temperature faster in cold weather and helping it stay up there while running to help with the auto-stop feature on HEV...

A few things have been done like cardboard to block the radiator and a few have slightly altertered the air circulation in the engine with warm air mods....

I was wondering about the practicality / plausability of better sealing / insulating the engine compartment....

Heat leaves the engine compartment from just about every direction ....

If the engine compartment is more sealed up and less heat can escape then it should warm up far faster .... especial since more than 30% of all the power produced by the engine is lost to as heat in the cooling system...

Insulating the engine compartment a bit should reduce the amount of energy and time it takes block heaters and such to warm it up....

Now as the engine compartment gets more sealed up and less heat can get out the more the engine will become dependant on the cooling system once it gets up to temperature to prevent it from over heating.... I figure this is the biggest risk / problem to figure out for this idea... for a given climate and temperature how much sealing / insulating can one add to the engine compartment safely without causing / risking over heating???

The secondary benefit from this ... is that I have also been reading about some people's efforts to recover some of the waste heat a car produces most focus on ThermoElectric Radiators and ThermoElectric Exaust Heat exchangers..... If the engine compartments heat losses were more controlled it would help to heat up and stay at temperature in colder weather and as these other waste heat recovery systems move from prototypes to the market in the next 5 to 10 years it would also be helpful for them to be able to have the loss of heat more controlled so it can better be channeled to the heatexchangers...

Has anyone tried much of this??? or have any links to articles about it???

thanks all.

You mean something like this?
http://farm1.static.flickr.com/131/328227089_5374f3c175.jpg
see also:
http://flickr.com/photos/efusco/sets/72157594428688334/

FWIW, I don't think it made a huge difference...probably the biggest benefit was that it allowed the EBH to get the ICE up to ~131F in the coldest of weather where I tend to see more like 121F without the insulation in there.
Still, I'll probably do it again next year b/c it doesn't cost much (and I still have the left over insulation from this year to reuse), it's quick and easy and might give some fractional benefit.

I'd like to find a good way to keep some insulation on the back side of the ICE...there's a bolt that sticks out and I'm thinking some of that compressed pink insulation might work if cut to size then held on with some sort of nut or something....just haven't gotten that fancy yet.

Like others have said, I still think a little 200W heater with a small fan that could attach to the intake for the battery to keep a continuous 60 degree or so temp for the battery (it wouldn't take much to keep it at temp once it's up, but cooling from a cold soak would be tough with something that small) would offer the biggest benefit in addition to the EBH.

that is a bit in the direction I was thinking... But I was thinking of going further....

For instance under the Engine most cars only have a cover that doesn't provide much insulation or sealage... the hoods usually don't close to form a seal and just close.... the radiator system pumps heat away from the Engine... blocking the air flow to the radiator just makes it less effective but it is still trying to pump the heat away from where we want it to be when it is cold outside....

Maybe What I am thinking of just isn't realistic....

I just keep thinking that the whole engine compartment seems designed with the idea that heat is a bad thing that needs to be thrown away fast and frequently at every opportunity.... when even excluding the exhaust the heat is at least 1/3 of the energy the fuel is producing....

Ideally I would think if we were building a vehicle from the ground up we would build the engine compartment sealed and insulated like a freezer is and then the controlled air intake for the combustion and the controlled cooling system could make use of as much of that "waste" heat that is produced as possible...

but since we aren't designing our cars from the ground up ... I guess this kind of sealing and insulating would lead to over heating of the current designs.... it just seems .... such a shame.

Well, the radiator won't circulate anything unless the engine temperture gets too high and needs to be cooled...that's the job of the thermostat.

I, too, have wondered at being able to have automatic louvers over the radiator, and there's no reason to not extend that to enclose the rest of the compartment, but expense, the possiblity of breakage, etc. all seem like good reasons to not include them.

Finally, you're right, it is designed to maximize getting rid of heat...that can destroy the engine, cold just makes it less efficient.

Hi guys,

Ian,

I have been working under the hood of the Insight for some time (search for blanket and engine over at IC), getting things moved around, and rerouted so I could do just what you are talking about. There will be panels, on all sides of the engine, top and bottom as well. I originally was thinking along the lines of a blanket, but the further along I got it turned into individually removable panels. I have suitable flame resistant material, not cheap by the way, from which to make the enclosure panels. the radiator will be on the outside of the panels, and therefore can do the job of heat dissapation as usual. There will be an opening on the back panel where the exhaust pluming will exit, and also for intake air to enter, although there will also be a temp controlled intake air controller, that will regulate intake air from both the cat and the ambient air factory set-up. This air intake, is one of the mods that I have done, in prep for the engine bay enclosure. There are two intake air paths, one attached to the cat coming out the back side of the air filter box, and the normal one from the factory set-up coming out the side of the filter box.

This is just some of what has happened up to this point. there is a lot of things to consider, which by your psots, I can see you have thought of. Cables to reroute, things to get out of the way...etc. I have taken pics of everything I have done, but I don't think I have put theme in the gallery yet, which I could do, if you are interested; However, you may be wanting to go another way. I am just now getting to the point of making the panels. Looks like this winter is going to pass before I get to evaluate anything in cold temps. Should be done by HF07, so everyone can have a good laugh.:D :D

For what its worth.

Randall

I have spoken with Randall about this project for some time, and feel it is worth the efforts to see what gains can be had. Controlling the engine/transmission environmental temperature and inlet air temp on a small 1 liter engine to get warm weather performance should definately help. Of course the denser cold air will still present higher areo. drag.

Along the same line of thinking, I was looking at the Insight engine that I am building onto a stand, and was wondering if running the water pump with a variable speed dc motor would allow the block temp to be better controlled than the direct drive stock system. The serpentine belt could be removed completely?
Winter will be ending soon (I hope), so we better hurry if we are to get any test time in.;)

Hi All:

___Insulated and or sealed off ICE bays are great for bringing up coolant temps but the real reason our FE goes to hell after coolant temps have come up is an ever increasing Rolling Resistance Coefficient. A test for any number of you … Stay below 30 after warm up has been achieved and look at your iFCD at steady state. An Insight at 0 degrees F will be lucky to see 70 mpg AFTER warm-up has already been achieved at 45 - 50 mph vs. 105 + in 70 + degree F temps. That leaves just one other factor and that is rolling resistance. Just coasting out of my drive in temps that low is impossible whereas at 70 +, I can roll down my drive, around two corners and down a thoroughfare in my sub for over 1/3 of a mile before going ICE-On.

___Not to break away from the discussion given we need to get coolant temps up much faster then an EBH or insulation etc allows so as to get away from the rich/high idle modes but once up and running, cold temps kill us due to today’s tires RRc more then anything else :(

___Good Luck

___Wayne

Hi All:

___Insulated and or sealed off ICE bays are great for bringing up coolant temps but the real reason our FE goes to hell after coolant temps have come up is an ever increasing Rolling Resistance Coefficient. A test for any number of you … Stay below 30 after warm up has been achieved and look at your iFCD at steady state. An Insight at 0 degrees F will be lucky to see 70 mpg AFTER warm-up has already been achieved at 45 - 50 mph vs. 105 + in 70 + degree F temps. That leaves just one other factor and that is rolling resistance. Just coasting out of my drive in temps that low is impossible whereas at 70 +, I can roll down my drive, around two corners and down a thoroughfare in my sub for over 1/3 of a mile before going ICE-On.

___Not to break away from the discussion given we need to get coolant temps up much faster then an EBH or insulation etc allows so as to get away from the rich/high idle modes but once up and running, cold temps kill us due to today’s tires RRc more then anything else :(

___Good Luck

___Wayne
No doubt about that, but considering we can't do anything (or much) about the aero drag and RR we must look where benefit can be gained. Further, the relative amount of improvement one can get from the EBH and engine compartment isolation is much greater, particularly at the beginning of a trip proportionally to what you would get from RR reduction techniques.

___Insulated and or sealed off ICE bays are great for bringing up coolant temps but the real reason our FE goes to hell after coolant temps have come up is an ever increasing Rolling Resistance Coefficient.

Hi Wayne,
I don't want to hijack this thread, but do you have some quick links/info on why this happens and how much the effect is? I'm curious how much of winter's FE hit is a lost cause because of this.

locutus,

There was a VERY in depth discuss a while back on IC titled :
Tire, Aero & other resistance vs. MPG (HIGHLY technical)

The result is basicly Rolling resistance is a big factor and goes up faster in cold weather than aerodynamics does... But both increase in cold weather the same time the Engine gives out less.... RR is the larger force for most cars up to about 40 MPH... In cold weather even the Aerodynamic Insight with Low RR Tires the RR is larger effective counter force than Aerodynamics up to about 50 to 60 MPH...

Go over to IC if you want to read the whole thing....

------------------
highwater,

yes that does sound more like what I was thinking of... but no small task and lots to concider.... I think you are further ahead in the concidering department then I am at this point....

------------
Mike,

I am no where near a test system for this winter.... maybe next year....

-----------
General,

I agree... the inishg talready has RR tires... already very Aerodynamic.... engin heta is all that lef for us to focus on.

locutus,

There was a VERY in depth discuss a while back on IC titled :
Tire, Aero & other resistance vs. MPG (HIGHLY technical)

The result is basicly Rolling resistance is a big factor and goes up faster in cold weather than aerodynamics does... But both increase in cold weather the same time the Engine gives out less.... RR is the larger force for most cars up to about 40 MPH... In cold weather even the Aerodynamic Insight with Low RR Tires the RR is larger effective counter force than Aerodynamics up to about 50 to 60 MPH...

Go over to IC if you want to read the whole thing....


I found it on IC. *Very* informative, thank you! :cool:

Hi guys. I'm keen on lagging my engine bay too but lately i've had to replace all the ignition coils in my renault scenic (at 80 euro each!). Turns out they dont tolerate the heat too well, especially since they are buried in the engine, down the spark plug holes. So while insulating the engine bay is good for mpg, the coils need to be kept out as best as possible from the heat. I thought maybe tying on some heat sinks to the tops to help remove excess heat from them. Its tight there so choices are limited.