Engine Cover Advantages?
 

Any reason why I should keep my engine and battery covers on besides aesthetics?

battery box is actually designed for air to flow around it... so better not to disrupt the airflow by taking of battery cover

i dunno about engine cover

congrats on first post
and welcome

Same for the engine cover. Keeps air flowing rearward and off the hood. Over time, the heat could damage the finish. That's my understanding.

Advantages, keeps the car looking very clean under the hood. Although Im not a big fan of all the plastic, it looks ok, very neat and orderly....esp when its all covered with armorall.

It keeps the air that flows in the nose moving around the engine.

Also is a buffer for heat, to keep it from baking the hood as much.

If you want to make the plastic cover more useful, why don't you wrap some potatoes in tin foil and place it under the engine cover. And when you get to your destination you can have some baked potatoes. Oh don't forget the butter, cream and chives. MMMMMM MMMMMMMMMM :icon16:

I always thought about how much heat that thing holds in, but of course I wouldn't want all that to damage my pretty paint would I? So I leave it on.

PLus it seems to help keep dust off, but that could just be all in my head. :)
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YamyNika live

it definately helps keep the engine bay cleaner. and as for all the "cooling" benifits, i'm not sold that it any of that. i think its primarily for decoration.

kinda unrelated, but sticking with the talk of plastic under the hood, I wraped the under side of all the front componets, ecu, battery, intake and fuse box with some insulation (2 layers of fiber re-inforced aluminium foil with 1/8" fiber glass in the middle) I used glue to attatch it to the plastic on the sides and bottom, with the parts on the car, you dont see the foil, but it shields that parts from quite a bit of heat. After driving around all the wraped parts are cool to the touch, vs the engine cover that is too hot to hold your hand on. Feels like at least 40*F difference in temps, its pretty amazing.

It doesnt affect airflow through the engine bay, or through the radiator...but it keeps all the parts nice and cool, and doesnt let those componets get heat soaked. I also still retain full use of the cooling ducts for the battery and ecu.

2nd thing I did was use high-temp foam to seal all the gaps around the radiator, and the opening of the bumper so that all that air that goes in the nose of the car goes thru the radiator, not around it.

Im not sure if any of this really made a diffence but it cant hurt.

Sounds like a pretty good idea, but I was thinking that theres only so much air that will make a difference when hitting the radiator. So forcing it through the radiator would possible only cause added wind resistance instead of any cooling affedts. But that would just be my first thought.


btw I like this smilie!

:bluesuit:
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Laguna Bay Condominium

True that you can only flow so much air through the radiator, once you go over 100% flow, you start to build pressure infront of the radator, causing drag....also if the air moves to fast over the radiator, it might not have enough time to grab heat, and you would actualy be worse off...although that is unlikely.

I didnt do anything extream, the stock radator has black foam around the radiator, to help direct the air thru it vs around it....but the foam they use is very cheap and thin, i just replaced it with better, stiffer foam, so its the same thing, only better.

again, none of that HAS to be done, and it might not make any difference, but I just like to tinker with cheap projects.

:dubs:

Ahh ... car-b-que!

there is no need for the cover it is aesthetic...

1. the masdaspeed front strut bar doesn't allow for the cover to remain...doubt they'd let that fly if the finish were to damage, remeber paint BAKES, went the temp here drops below -10F the paint starts to get brittle...not the other way around

2. there is already insulation on the hood

But don't put the butter under the cover.... :uh::lach:

This is actually not true: Heat transfer on short-time contact is MUCH more efficient.

I used a Dremel tool and cut the holes open a little larger and filed down some of the ribbing on the underside (in line with the strut brace) and my cover fits fine with the Mazdaspeed Strut Brace. I think someone here did a temp comparison and the cover did lower the temp in the engine bay, albeit slight.

is that true in all cases? The air can only hold so much heat, the faster the air moves the more heat it can carry away, but I would think that there is a point that the air reaches peak efficency for heat transfer, any faster or slower and it is below peak, cause its there to long or not long enough.....or that the friction of the air being forced through the passages is creating more heat. Although I wouldnt think this (or any) car coulndt reach those speeds/flow rates thru the radiator, hence why I said its not likely. :dunno:

I would have to say that the cover makes a BIG difference in cooling. After installing a Mazdaspeed strut bar, I left the cover off for a few months. Pretty much after every single drive where I ever went over 3000 RPMs, the cooling fan would always come on (where you can clearly hear it whirring for a few extra seconds after shutdown before the fan finally shuts off). I finally modified the cover so that it'd refit over the Mazdaspeed strut bar, and now the cooling fan rarely comes on. So I think that cover makes a pretty big difference.

my experiences with it are exactly the opposite. back in the summer when it was freakishly hot, my fan would stay on for over an hour when i had the cover on. so i took the cover off, and the fan either didn't come on, or would only stay on for a short period of time (less than a minute) after shutting the car off.

Yes, it is true independent of the circumstances of the heat transfer. The reason is that with increasing contact
duration the temperature difference in the boundary layer decreases, which means less driving force for the
heat transport. For short time contact, the heat transfer over time follows a curve defined by 1/sqrt(T), which merges
into a more shallow exponential curve (with decreasing exponent) for long term contacs.

Therefore radiators are always very thin but have a relatively large frontal area (lots of short-time contact).

wow, learn something new every day, thanks. so i guess my little mod might work out better than i thought

I've actually done that on roadtrips.. not in my rx8 mind you, but in my 2001 dodge dakota driving from florida to oregon... good times..

I wouldn't foil anything in the engine compartment coz when I asked my mechanic, he told me while the things inside are too hot to touch after a drive, its actually good because it means they are helping radiating heat away but who knows.

heheh guess i'll keep it on. figured out how to check the oil from the side anyhow.
but dang, that dipstick is buried deep...

I havent had the engine cover on my 8 since I installed the Mazdaspeed strut bar, that was about 2 years ago. I have had absolutely no ill effects on performance nor any heat damage to my hood.

THANK YOU

real evidence finally

:ylsuper: