Insulating the engine - how to do it?

[landspeed]

Hi!

One idea I have had for a while is insulating the engine. The idea is that, if you
drive in to work, then have to drive a bit at lunch, the drive home, there will be
a lot of short, cold-start journeys. If, however, the engine had a lower rate of heat loss when switched off, it would be a lot warmer when restarting, meaning less time to reach full operating temperature, and much better fuel economy.

My idea would be to apply some kind of insulating material to the engine. Obvious considerations would be the need to avoid the area directly around the exhaust manifold. I still think this could have a very beneficial effect, especially as cooling will be taken care of via the cooling system anyway.

Does anyone have any ideas of which material could be used for this? I suppose fire-retardant material would be the best!

Does anyone have any views on this particular modification?

[Headshot Zod]

they actually make blankets for engines to keep the heat in but this is more easily used over nights. You would be better off using a gasoline fired engine heater or using one of those "thermos thingees" the Toyota Prius uses.

[lovemysan]

The belly pan helps this a bunch

[landspeed]

I have had thoughts about those thermos things, including a way to do one (would have to use 12V fluid on/off relays, but would be very easily wired in to the system). It is something I will consider in time.

lovemysan: I don't know what the aluminum side trim is (found your 11/11/2006 belly pan thread)... Did you use the strong metal strips, and aluminum sheet, or is it plastic sheet?. If it is plastic sheet, any problems with the exhaust heat yet?

I still think I'm going to insulate my engine - but a belly pan is also definitely on the cards as well!

[JanGeo]

Humm belly engine pan might be a great thing to do for the winter to get the drive train warmer too.
My xB dropped 184 to 143 degrees in 20 minutes parked about 40 degrees - outside temp 50's. A little sealing on the hood to fender gap will trap more heat in and a little in the front should pocket a lot of heat - the underside of the hood is insulated and does not get warm.

[DracoFelis]

Originally Posted by landspeed

One idea I have had for a while is insulating the engine. The idea is that, if you
drive in to work, then have to drive a bit at lunch, the drive home, there will be
a lot of short, cold-start journeys. If, however, the engine had a lower rate of heat loss when switched off, it would be a lot warmer when restarting, meaning less time to reach full operating temperature, and much better fuel economy.

I've thought of this as well. However, it might be more trouble than it's worth, as you would have to be vary careful not to retain "too much" heat (remember, engines naturally produce so much heat, that cooling is often needed). I suppose the "best way" to handle this, is to have some insolation (some type of "blanket" perhaps?) that you put on when you shut down the car, and take off when you drive).

One thing I would suggest, is to go with a full "grill block" (I use coorplast for my grill block) in the winter, as it's a double-win FE wise (by giving you better heat retention + better aerodynamics). I know my CRX heats up a lot faster (and keeps its heat longer) now that the grill block is in place. And I also know that my gas mileage (while down from my summer high) is now consistently above what prior years had for MPG during this time of the year.

However, even with something that insolates as little as a grill block (for example, the underside of my engine compartment is still fully exposed to the outside air), you have to monitor things. For example, I found that my radiator pump kicks on (indicating that the engine is quite hot enough, and is trying to cool down) a lot more (especially on those slightly warmer days, were the outside temp may get up to the low 50's) now that the grill block is in place. I suspect that as the outside temp cools down (as the winter progresses), this will be less and less of an issue. But (in the mean time) I would be hesitant to insolate the engine compartment even more (and thereby risk problems due to engine over-heating)!

And remember, the only "engine insolation" I did was to block the air flow through my car's grill. Considering how much that change affected things, I fear I would be in a real danger of "over heating" if I insolated the engine compartment even more. I suppose it would likely be "safe" to do something (such as a flame resistant blanket) that could be added when the car is shut down (and removed before startup). However, manually adding/subtracting an engine blanket seems like more of a PITA than the extra FE is worth to me. OTOH if that hassle is "worth it" to you, I say "go for it"...

[red91sit]

Originally Posted by DracoFelis

I've thought of this as well. However, it might be more trouble than it's worth, as you would have to be vary careful not to retain "too much" heat (remember, engines naturally produce so much heat, that cooling is often needed). I suppose the "best way" to handle this, is to have some insolation (some type of "blanket" perhaps?) that you put on when you shut down the car, and take off when you drive).

One thing I would suggest, is to go with a full "grill block" (I use coorplast for my grill block) in the winter, as it's a double-win FE wise (by giving you better heat retention + better aerodynamics). I know my CRX heats up a lot faster (and keeps its heat longer) now that the grill block is in place. And I also know that my gas mileage (while down from my summer high) is now consistently above what prior years had for MPG during this time of the year.

However, even with something that insolates as little as a grill block (for example, the underside of my engine compartment is still fully exposed to the outside air), you have to monitor things. For example, I found that my radiator pump kicks on (indicating that the engine is quite hot enough, and is trying to cool down) a lot more (especially on those slightly warmer days, were the outside temp may get up to the low 50's) now that the grill block is in place. I suspect that as the outside temp cools down (as the winter progresses), this will be less and less of an issue. But (in the mean time) I would be hesitant to insolate the engine compartment even more (and thereby risk problems due to engine over-heating)!

And remember, the only "engine insolation" I did was to block the air flow through my car's grill. Considering how much that change affected things, I fear I would be in a real danger of "over heating" if I insolated the engine compartment even more. I suppose it would likely be "safe" to do something (such as a flame resistant blanket) that could be added when the car is shut down (and removed before startup). However, manually adding/subtracting an engine blanket seems like more of a PITA than the extra FE is worth to me. OTOH if that hassle is "worth it" to you, I say "go for it"...

I was thinking of this too, but in theory, the radiator is the only part of the engine that does cooling (and extra fuel), so if we were to duct our radiator, we should be able to seal up the engine compartment relatively tightly. Also, a radiator block lessens cooling, but an undertray actually improves it. So adding one of them should decrease your chances of over heating. As far as insulating the engine bay, I was actually planning on doing this. The part that makes me worry is the other components in the engine bay. The engine is fine to be sealed up, reaching highest temperatures slightly after it's turned off, (cylinder temps and block still super hot, but radiator no longer cooling the vehicle) If the engine bay was sealed, i would imagine the entire area would become quite hot, and many of the things placed in there are not designed to become as hot as the engine. The exhaust system heat could get a very well sealed engine bay EXTREMELY hot. My old car's fan would actually stay running for up to 20 minutes after the car was shut off to help cool all the components off. It seems like a real good idea.

On my current car, I'm running a nearly sealed radiator block (I think it sucks air from around the radiator instead of through the grill) and a 1/2 underbody going to the transmission pan. It does warm up quite a bit faster than before the modifications and stays warm for a while longer after getting shut off. In the summer though, i noticed driving it excessively slow 10-20 mph, for more than about 15 minutes and the engine comparment would emit continous gray smoke haha.

[landspeed]

I've been thinking about it a bit more. On my car, I did a 500 miles journey using an almost 100% rad block (bin liners in the bay, across the entire radiator front!), and it went up to the temp when the thermostat opens fully, but never got any hotter. Even when doing some drag-racing (on a private road of course...) against my friend. Also, on a drive where I would normally get 28(UK) MPG, I got 35 (UK) MPG!

I'm thinking of getting a small custom stainless radiator, then doing a 3/4 grill block, with the only open grill area being where the radiator is. The lower grill is where I'm going to put a long intercooler. Then, what I could do, is put in a belly pan, and then think about some engine insulation. My car has an analogue temp gauge, so it is very easy to keep an eye on the temperatures!. So, expect to see me on here soon, asking about how to do a belly pan!.

The other thing is, my car is quite an unusual design, and has a 30 degree rear hatch (see my car pic 'Bluey') - which I have just learnt is the worst thing I could have for fuel economy. I will try some airtabs for this

[onegammyleg]

Could always get granny to knit a jumper for it.