Cooled engine bay
 

heres my idea. i want to make a cooling device like whats found in mini fridges into my hoodscoop and front air intakes. i kno cooler air is more dense so it would help the engine breath, i would have all the cooling devices electric and wire them to the inside. i am also thinking about installing a second alternator on my engine where the ac compressor would be. here is my design.

Attachment 405294

Re: Cooled engine bay
 

It will take more power to cool the air than you'll ever get out of something like that.

Re: Cooled engine bay
 

just put your air cleaner high up in the hood cowl with an air tray that seals to the hood so the air is taken from the rear of cowl opening. plenty of cool air there

Re: Cooled engine bay
 

what you mean more power?

Re: Cooled engine bay
 

how much HP you will lose from the extra alternator is more than you will gain from getting a few degrees cooler air into the engine. if your car is a TBI or carburated you may even want the slightly warmer air to keep the fuel atomized and prevent it from puddling in the intake manifold before it enters the combustion chamber.

Re: Cooled engine bay
 

its a carbed 1990 iroc, i wasnt concerned with hp, i have plenty, i dont have an ac compressor and i have an electric fan so its not powering much anyway. and also i dont plan to have it very cold like a fridge, just not even really cool, just kind of warm and cozy for the engine lol

Re: Cooled engine bay
 

sorry but IMO.. POINTLESS. you might as well turn your smog pump into a supercharger haha :crazy:

Re: Cooled engine bay
 

Why would you even think about doing this then?

Re: Cooled engine bay
 

Under the hood gets really hot because you have a motor there generating heat and exhaust giving off a ton of heat. I dont think you would even notice a difference in under hood temps if you did this. There would be no logical reason at all to do this.

Re: Cooled engine bay
 

that would be like building a walk in freezer around a wood stove.

I like how you are trying to think outside the box, but you need to research ideas and think them out first.

Reminds me almost of the Direct Exhaust Injection guy

Re: Cooled engine bay
 

Reminds me of the leaf blower mod

Re: Cooled engine bay
 

i could lower the temperature about 100 degrees if needed, but like i said, i dont want it "cold" under there. and when i said hp isnt a concern, i meant about running another alternator, its like living in my house, ill be ok if its 50 degrees or 90 degrees, but being comfortable will be much better, i want under the hood to be a controlled temperature to create the "just right" environment. i already have my headers wrapped.

Re: Cooled engine bay
 

Everything under your hood is already perfectly comfortable.

Re: Cooled engine bay
 

If you want the "just right" environment its obvious that you want to make it more efficient.

If you really want to "cool" off the engine bay the easiest most effect method is to either vent it properly, or install a Bilge fan. Even then, this fan would only really be effective when idling because there isn't enough forced air coming in from the air dam / radiator area.

Re: Cooled engine bay
 

underhood idle temperatures average about 300-450 degrees C and during driving, the temperature around the exhaust headers/manifold reach up to 500 degrees C. i just figure that if i lower the temperature outside the engine to the engines normal operation temperature which is about 115 degrees C, things would become more efficient.

Re: Cooled engine bay
 

Measure the air temperature under the hood, and i'm certain you'll find it a lot cooler than 115C already.

Re: Cooled engine bay
 

If the average air temp were 350c, or about 662*F your plastic wire loom would be melting just sitting in the bay.

It may be that hot very near to the exhaust, but the average temp about 12 to 16" away from the motor should be nowhere near 600*F unless you have red hot glowing headers. And if they are glowing then either your car is making some serious power, or something is seriously wrong.

Re: Cooled engine bay
 

How much air do you think goes through your engine bay? Don't know? Assume it's MORE than the amount that goes into your engine. What's that amount on average? >100-300 CFM? Maybe 4-25X that?

You're looking for a delta t of how much? Keep in mind that's AFTER you sweat the moisture out.

Those little fridge coolers are designed to lower the temp of a VERY small amount of air and that VERY small amount of air is recycled over the coils continuously (at least until the door is opened-but the fridge would never cool if the door were left open, right?).

Your proposed requirement would be to cool 100% make up air (all fresh, hot and humid) with no return air (return air would be air recycled across the coils until the humidity is lowered (condensate created) and the temp is dropped (delta t)). Make up air likely in the neighborhood of several thousand (1000s) of CFM...Let's do the math....no YOU do the math.

See why it's silly? :)

Re: Cooled engine bay
 

those temperatures i stated were averages taken from normal vehicles from normal operation to the point where things fail. cooling under the hood would be easy, i have many years in refrigeration and i kno what i have to do to lower the temp, i could easly lower it to freezing with the materials i have access too, but i was only wondering would having the bay cooler help the engine or would it not make a difference?

Re: Cooled engine bay
 

What Apeiron said: the engine is perfectly comfortable now.

Internal engine temps MUST get above the boiling point of water in order to 'boil' out the H20 that gets in the oil before it generates acids (same thing that happens to a compressor...). We all know that H2O is a normal byproduct of hydrocarbon combustion and some amount is going to get into the crankcase.

Normal motor oil needs to reach temps to achieve proper viscosity, more important though is that all of the engine tolerances are designed for the intended operating temperatures...what's the thermal coefficient of expansion for steel? around 6.6 x 10^-6 /F?

I also beg to differ on the 'easy' part....

Re: Cooled engine bay
 

No, very obviously you don't.

Re: Cooled engine bay
 

i was planning to use cryogenic oscillation technology, similar to what we use in the plant to create condensation. doesnt require too much electricity, i kno that engine has an optimal temperature of operation where the oil is at the right viscosity and that theres is a perfect temperature where the air density and fuel mixture would be perfect. i simply want to keep the temerature at this level. not trying to make a fridge under the hood or anything

Re: Cooled engine bay
 

In my opinion it's a neat theory, but it's just extra power, extra weight, and extra things that can go wrong. I don't think it will cool enough to see a difference.

Speaking of weight I'm not sure how well the hood would support the condensers.

By all means give it a shot and let us know how it works. We like pictures too :-)

Re: Cooled engine bay
 

instead of blowing air in and causing an even bigger high pressure area, build an extractor hood, cooler engine bay and a lower pressure there

Re: Cooled engine bay
 

i had plans to vent the air to the rear of the car, i did want to feed all that air under the hood because of like you said, the air pressure, most of the set up would be in the trunk of the car, about 30lbs worth, the equiptment under the hood would be minimal, only thing needed under the hood is the electrostatic plates and there hoses. im not trying to brag about my knowledge but i had no doubts or questions of "if" this could be done or "how", it doesnt way much, if it ever failed, what can happen? the temperature returns to normal? i just wanted to kno if it would be a good thing for my engine, and if so, i would work on a more presentable everyday person design that i could maybe mass market?

Re: Cooled engine bay
 

The guy is joking about this.

Regardless, your motor would be lucky to get 20% efficiency. This means that for every 10 gallons of fuel you burn in your car only 2 is used for what you want, acceleration/ac/water pump etc. There is no way you can take the 20 percent of the useful energy out of the fuel and use it to cool what the other 80 percent has turned into pure heat.

As it was said, everything under your hood is happy at the elevated temperature. The concept is comparable to running a AC unit with the doors open to cool the outside air. You do not put the ac condensor in the same compartment as the evaporator.

If you are going to concentrate on cooling anything there is only one thing that matters, the actual air that goes through the intake.

Re: Cooled engine bay
 

There is no joke. It's not like trying to cool outside with an ac. It's a confined space with a small amound of cubic feet. I'm not using an ac condenser to do any cooling. And the air that goes into the intake is the air under the hood. I have a carb. Don't burn me if u don't kno what's going on. Like I said. I have no question that I can cool it. I'm not using any fans or ac compressor to do so. My question was if the engine would be more efficent running at an optimal underhood temp.

Re: Cooled engine bay
 

How many BTU/hr were you planning on extracting, and where were you going to move it to?

Re: Cooled engine bay
 

LOLS@ this thread..


why are you guys even egging him on?

heres what you will gain by doing this..

absolutely no difference in horsepower..a lighter wallet...and a bunch of time wasted.

PERIOD.

/thread.

Re: Cooled engine bay
 

I am not waisting my money because i dont have to buy anything. and im not waisting my time, what else do i have to do? might as well invent something. i just dont understand why having my engine bay cooler wouldnt help.

Re: Cooled engine bay
 

You are wasting your time.

You are wasting energy.

You will use more energy, then you will help create.

a cowl hood would do a better job then you have planned, and wont need an energy source to do so.

If you are so sure that what you are doing isnt a waste of time/money/effort...then DO it.

Everything you have said is a contradiction to everything you've said previously.

Re: Cooled engine bay
 

can anybody answer my question? its my time and my energy. nobody who has commented knows about these things i have. dont worry about if i can get it cool, dont worry about how much energy its gonna take. thats not what im asking. i know what it takes, and i have just that. if anybody is interested in learning something, i can explain my method. i just want to know will the engine benefit from being at a constant optimal temperature on the exterior.

Re: Cooled engine bay
 

It's been stated before..you do not know what you're doing.

You seem to think you are so very well informed about thermodynamics, how come you cannot answer your own questions?

What you are doing, will have absolutely ZERO benefits, ZERO gains in terms of power, and ZERO gains in terms of fuel economy.

What you will gain, is unneeded weight, which will in turn take more power to move, which will inturn creat more heat.

Like i have said, Kudos for thinking outside the box, but your ideaology here is flawed.

Air cooling, no matter how efficient, is never as effective as liquid cooling, you blowing "cool/warm" air around the engine isnt going to do anything, when internal engine coolant temps are 180*+ and oil temps are in the 200* range.

Re: Cooled engine bay
 

you are completely missing the point. im not using any fans to cool anything by blowing any air around. i am making the air more dense, thus creates cooling, which also moves the air. i said nothing about internally cooling the engine. i want to match the internal temperatures with the exterior. im asking will the engine be able to breath better because of the dense air. the heat by product of my cooling equipment wont even be under the hood. it will be exhausted in the back. the full scale equipment we use takes 220 volts to cool super heated water vapors that are hot enough to glow the pipes without. the vapor is rapidly cooled to 5 degrees c and the process starts over, the heat is converted to electricity. this is my job. i do it 4 days on, 4 days off. been doing it for 15 years now. dont need anybody telling me i dont know what im doing. im just asking for help, not to get my intelligence insulted.

Re: Cooled engine bay
 

You are a lost cause.

Re: Cooled engine bay
 

thanks for the insult.

Re: Cooled engine bay
 

I don't think that this is a lost cause altogether. Dyno test cells are air conditioned after all, albeit in a much looser sense of the term.

The main issue I keep coming back to is this: interface time of the air with the cooling apparatus. The shorter the cooling time, the greater the input of energy into the cooler to cool the air enough to achieve desired results.

I think you might be trying to over do it a bit. There are a few changes that could be made to make this thing work a bit better. Not trying to insult your intelligence, but you need to look at two facts here: the engine bay isn't sealed and generally has air pulled out at the bottom and warm air always rises.

To maximize your efforts, start by insulating the headers to help minimize the amount of "direct" heating of the engine bay. This is your biggest source of waste heat outside of what comes from the radiator. Second, duct your radiator exhaust somewhere else besides the engine bay. Now that you have your two big sources of waste heat under control, you can better size and focus on physically reducing the radiant heat of the engine itself.

Exploiting the fact that warm air rises, remove the cooler on top the engine and just use a cowl hood, or make the mods to the hood for passive heat extraction. FRYCHKN has a really nice thread on the how to do just such a thing: https://www.thirdgen.org/forums/fabr...tor-build.html Doing this will create a pressure differential that will pull the warm air out from the top. It'll also pull the "cold" air your cooler is making up from the bottom.

Next, come up with a way to "seal" the engine bay so you can have a consistent and known flow path for the air over the engine. Duct your cooling in from the front and make sure that you have room for the radiator ducting as well. You'll probably need to make something like spoiler/air dam to make the air go into the cooling apparatus. Only problem here is that your underbody aero will change with a sealed engine bay. Probably not enough to affect anything, but something to keep in mind.

Once these things are done, then you can size the cooler to your goals. Keep in mind, ground level air temps are about 30F higher than air temps (concrete loves to hold onto heat). Since you have all the trunk to play with, no reason alot of this stuff won't fit in the car. Also, I don't think you'd need a second alternator. Just take one of the HD alternators off a diesel truck and use it. Some of them are in the 300 amp range IIRC.

I'm in the nothing ventured, nothing gained crowd. While I do think your going a bit overboard here, if you get the engine bay to be a constant 150F to 175F, it'll be an impressive achievement.

I'm interested in what kind of cooler you'll be using. Is it something like a Peltier phase change device or something more conventional?

Re: Cooled engine bay
 

my device charges the air to bond together, which makes it cooler, it runs off electicity. the more i turn up the juice, the tighter the air will bond together, its good that the car isnt sealed because when the air bonds together, it pulls in more air. so if it was sealed, it would crumple like a soda can. the air will be moved because of the particles bonding together. thats why i was saying with enough electricity i could cause the air to be below 0 if needed. at my plant, we use this technology on a much larger scale. the only heat produced would be from the equiptment itself which would be in the trunk. i drew the picture that way to help people understand sorta what i was thinking without having to get to indepth but i guess its called for now.

Re: Cooled engine bay
 

So it condenses the air which makes it cooler? Makes sense. I'd still stick to my list of recommended tweaks, but don't seal the engine bay and add a variable control circuit to control the current. Lower current at idle and higher current at speed.

Sounds very interesting. Do you have pics of this cooler?

Re: Cooled engine bay
 

ill take pics soon, but i planned to use a thermostat like the ones on the wall at home, but more industrial, set it to about 180, and it will keep it that temperature. and yea defiantly dont seal the bay, ive seen a clogged pipe at work that crushed in like a soda can at the bottom of the ocean. wont have to worry about that though because of all the openings in the car.

Re: Cooled engine bay
 

one thing about a peltier device or "thermoelectric
cooler"is one side gets cold the other side hot,so large
heatsinks will be needed to keep the peltier junctions
working...

Re: Cooled engine bay
 

it doesnt work like a peltier unit. those get hot on one end and cold on the other. my device uses ionic plates that dont change temperature. they just cause the air to condense.

Re: Cooled engine bay
 

That sounds an awful lot like the magnetic constrictor coils used in particle accelerators.

Re: Cooled engine bay
 

a good house hold example is kinda like the ionic breeze? you kno that little thing that cleans the air with no fans? well it charges the ionic plates to attract the air to the filters and the air passes through, im charging the air to itself. with industrial strength. so i guess its like an ionic breeze on steroids and crack. lol

Re: Cooled engine bay
 

This isnt going to do a damn thing, why cant you people understand this?

its NOT going to increase economy, its NOT going to increase power, its NOT going to do anything, except waste the OP's time, and add unneeded weight to the car.

This isnt a hard concept to grasp you guys. Im all for thinking outside the box, and new ideas...but this concept/idea shows no gains, no function, and just COST.

This will do as much good as the Tornado air thingy.

There is always constant fresh air flow throughout the engine bay, be it at idle, or cruise speeds, im seriously failing to see the point of this idea.

Re: Cooled engine bay
 

Obviously you don't understand what's going on then. Nobody is talking about airflow. Or fresh air. If u don't understand, why negativly comment. I can understand constructive critisism but that's plain old childish. We are adults here for the greater good of our cars.

Re: Cooled engine bay
 

No, obviously you do not understand.

im fully aware of what you are "trying" to do..

and i, as well as other members, have told you its pointless.

But hey, if you like to waste your time and money, who i am i to stop you?

Re: Cooled engine bay
 

I'll be the a-hole.... because your idea is f'n stupid. Is that clear enough ? That is what the other people who 'get it' are nicely saying to you.

Re: Cooled engine bay
 

somebody please tell me whats stupid about cooling the engine bay

Re: Cooled engine bay
 

With an A/C unit?
plenty. As the car moves, what little A/C cooling you could provide wouldn't amount to sh-t.

To cool the engine bay (with running engine in it), it would have to be 100% sealed from outside air, the A/C would have to recirculate the air (like your house hvac) and, the A/C would have to produce enough BTU cooling to negate the heat BTU produced by the engine (like a 460v industrial refrigeration unit).

But hey, go for it, good luck.