Insulated Engine Compartment for Better Fuel Economy?
 

Hello All!

Being winter, we all get a little more concerned about heat, and how to keep getting good fuel economy, despite snow on the road, and thick engine oil bogging us down.

Typical EcoMods for winter usually include use of a block heater, and blocking much of the radiator.

What I am curious about is the concept of an insulated engine compartment.
If you use a block heater, wouldn't it work better if the wind didn't blow the heat away, and it didn't just radiate out through the hood?

Has anyone experimented with insulating or wind-proofing their engine compartment for improved winter performance?

If so, I would LOVE to hear about it!!!!

Thanks,

-Ben

Short answer is yes.

Long answers: ;)

http://ecomodder.com/forum/showthrea...tion-6052.html

http://ecomodder.com/forum/showthrea...ion-11141.html

I've been thinking about this with the Metro. With some cars, once you open the hood, there is nothing visible of the engine or the ground beneath anyway, and seemingly the only insulating you could do would be to squirt "Great Stuff" in the nooks and crannies, and this doesn't seem like it would be a good idea.

That's right, I forgot about the "Hood Blanket" thread.

My truck is a 1995 Chevy S-10. You could get those with the 4.3L or 2.2L engines. Mine is the smaller, which is nice because there is a little more room to work around it.

The insulation that was on the underside of my hood was pretty much gone already, just from the typical winter field mice activity of the last few years.

I pulled out the black plastic "nails" that held in what was left of the original hood insulation and used it as a template to make a new one from radiant barrier - a combination of mylar and bubble wrap.

I left the radiant barrier insulation a little long, so that it could wrap down past the hood hinges. Then I made a few cuts so it could get rolled back, specifically where is came close to the engine or exhaust manifold.

http://photos-e.ak.fbcdn.net/hphotos..._8120543_n.jpg
http://photos-f.ak.fbcdn.net/hphotos..._6917199_n.jpg

I already had an inexpensive outdoor thermometer unit that is battery-operated, so I temporarily pinned it inside the engine compartment (with the green Eco-clamp) to see if I could get temperature data. (While I do own a ScanGauge, the truck does NOT have OBD2, so I can't use that for temperature info.)
Also, the thermometer is wireless, and conveniently broadcasts to inside my nice warm house....:thumbup:

http://photos-f.ak.fbcdn.net/hphotos...8_579090_n.jpg

I'm running my 400 watt frost plug block heater right now to see if I can get a trackable difference in air temperature inside the engine compartment.

There is also this recent thread: :rolleyes:

http://ecomodder.com/forum/showthrea...tor-10572.html

In my attempt to retain ICE heat, the foil/foam/foil is wrapped loosely
around the front, top, and rear of the ICE. It's still there now some 2 months later.

I'm continuing to see a 2-3 MPG increase in my typical 28 mi. daily round trip
commute. This may be mostly due to ~5 degF increased coolant temps via
ScanGauge in the 185-195 degF range. I do roughly 35% highway, 65% urban
driving.

In my limited experience, when it's windy and you're at a standstill, you'll need
a tight fitting "cozy" around the ICE to keep heat from being scoured out from
the engine bay.

Still, every little bit of MPG increase helps. :)

I wrote down some readings of temperature over time, inside the engine compartment of the truck with the block heater running.

4:00 PM - 31.8F
4:05 PM - 31.6F (had the hood open)
4:24 PM - 35.6F
4:46 PM - 39.2F
5:01 PM - 40.1F
5:18 PM - 40.6F

It sure seems to show that the block heater does make a difference in the air temperature inside the engine compartment.

Nearly a ten degree difference in an hour and 18 minutes doesn't seem too bad!

Now, I just want to keep some of the heat in there!

Ben - You have two trucks?

After a belly pan and hood blanket, the best thing I can suggest is literally blanketing the engine with something.

Liquid cooled engines needing airflow to cool them is, as you know, a myth. The block blanket might slightly raise engine temps, but it's not going to hurt anything.

Yes, I actually do have two trucks.
The one I am driving is a '95 with the 2.2L 4-cylinder gasoline engine and 5-speed transmission.

The other one is a parts trucks - the exact same configuration, (even the same color!) except that it is a '94. That truck is becoming the "Mer-Chevy".

Both trucks can be experimented on as much as I want, as long as I still have something to drive long distances for my work.

Any (useful working) eco-modifications to this truck will simply be transfered to the other one when I get that engine swap completed. Block heating will be even more important with a diesel engine, but for now, I am just trying to get a little more out of my gas engine.

Wow, I somehow thought that you only had the one truck, and were converting it on a time budget. Woe is me!

I think the two spots that lose the most heat in the engine are the oil pan and the valve cover. If you can insulate either of those, you'll likely keep more heat in the engine. The oil pan shouldn't be too difficult, if you can find another OEM one, gut the windage tray from it, and replace a couple of your oil pan bolts with studs that are long enough to hang the second one on as well. You might have to hammer the second one out a little bit for it to fit nicely, but that will allow you to use airspace or some decent insulation to keep heat in the oil and protect against air movement releasing heat from the oil through the heat sink effect.

The valve cover... you've got me on that one. No idea. The heavy iron block and aluminum head probably don't lose too much heat comparably.

The added benefit to using the second oil pan is that you can add a heater right there in the pan.. I just suggested this to Orange4boy in his Prius thread. That pipe-tape heater you used on the Electro-Metro's batteries just might do it for you, if it's a decent heating element. It's nice to heat the coolant, but oil flows through the entire engine, and touches places that the water never sees.

OK, just thinking off the top of my head. For the valve cover, maybe mold some aluminum foil over the parts you want to insulate, then spray on a layer of "Great Stuff". They have a variety of this that is called "Fireblock". I think this stands more heat than the regular stuff. Make sure you don't get it on other stuff in your engine compartment, and that it doesn't expand too much. Given plenty of time to cure, you should then have an easily removable insulating shell!

( I haven't tried this, and bear no responsibility for your own experimentation. But give it a try and let me know how it works, and then I might be next!)