Engine Bay temperature

[Pete38]

Does anyone have any idea what temperature the area around the fuse box gets up to? Reason I ask is that I am changing my fuse for the dual battery to a circuit breaker thats good up to 82 degrees... Now my feeling is that out near the battery and fuse box it won't get this hot but I do know it gets pretty warm under there.... Hmmm, now I think of it, some plastic bits aren't good to touch on a summer day so a little concerned now... I'm going for 60 degrees plus/minus 10 degrees.

Anyone measured it?

Peter

[benji]

I've got a 140A circuit breaker infont of the battery. It's one of the Jaycar ones. Same as this but 140A

http://www.jaycar.com.au/products_uploaded/productLarge_5937.jpg

It's been fine so far. Not tripping on a really hot day running the winch.

[Keithy P38]

I have a 50amp circuit breaker in behind the battery on mine and it makes light work of our high 30's/low 40's days up here. That's with hot low range driving as a regular occurrence.

I can't suggest a temp though, but at a guess, I'd say damn hot! Mine goes to fast idle on a hot day out bush if I let it sit in the heat idling long enough.

Cheers
Keithy

[Hoges]

Does anyone have any idea what temperature the area around the fuse box gets up to? Reason I ask is that I am changing my fuse for the dual battery to a circuit breaker thats good up to 82 degrees... Now my feeling is that out near the battery and fuse box it won't get this hot but I do know it gets pretty warm under there.... Hmmm, now I think of it, some plastic bits aren't good to touch on a summer day so a little concerned now... I'm going for 60 degrees plus/minus 10 degrees.

Anyone measured it?

Peter

60 deg C +/- 10 is probably a good estimate. Depends also on the ambient temp. Sunday before Christmas we were on the Hume Hwy heading north and the external temp when we pulled over for a coffee break in Gundagai was 42 deg C. The OBDII air intake temp reading was 56 deg C. Had the vehicle been left parked in those conditions for more than a few minutes, I reckon that with heat soak the engine bay temp would have climbed well above 70 deg C at least. The (Java black) bonnet was scorching hot ...don't ask :( The coolant temp was a steady 94-96 deg C.

[Pete38]

Thanks all. Looks like the fuses will get replaced by circuit breakers then...

I'm going to make a few circuits that beeps when either the front of rear circuit breaker breaks.

Reason being is that I have 4 AWG cable running to the rear but wanted to under rate the circuit breakers between batteries at 100A. If the circuit breakers trip, well the winch will still work from the front battery and so will the 200A+ inverter in the rear (on the 12V side). In saying that though I have used the winch and it didn't blow the 60A fuse between the batteries but I wasn't winching too hard... Just a stuck toyota ha ha.

So as long as the breakers beep when blown, I will just reset them after I finish doing what I am doing. Because I will then know rather than just have the rear battery not charging without knowing.

If anyone is interested in the circuit then let us know. Probably try it out next week sometime.

[mtb_gary]

Just curious how many of us still have the insulation on the underside of the bonnet? For mine I took it off several years ago as it had perished and was starting to fall off.

Gary

[Hoges]

FWIW: The under-bonnet "blanket" on my vehicle is still in good nick ...July 1999 build Thor 4.6, 150k on the clock.

[Keithy P38]

Still got it on mine Gary. In good nick too!

[mtb_gary]

Whilst mine gets hot under the bonnet I was wondering if the insulation blanket is keeping some of the heat in? Removal of the blanket has not caused any deterioration in the shiny black paint on the bonnet. Bonnet was replaced around 4 years ago after a kangaroo head butted it.

Gary

[TheTree]

HI

Mine still has the insulation and I wonder if it is more for noise reduction than heat control?

I am going to fit Thermo fans with a run on timer to dissapate the heat more quickly

Steve

[glenhendry]

I am with you on both counts SteveFarmer. I believe that it is more to do with sound insulation, and I too have bought a turbo timer to run the thermofans for ~2 mins after killing the engine.

My under bonnet blanket is inplace, but looking a litte tattered in places. 2000MY with 275kkm.

[benji]

Thats a great idea; I believe the ecu sometimes runs the condensor fans after shut down to dissipate heat, but shutting down at 100c they dont come on - which I would consider a high temperature.

I've got the right wheel liner off at the moment, and there's noticeably more heat coming out from the drivers side; so the heat definately 'pools' up at the top.

[TheTree]

Hi,

I have ordered the Dakota digital fan controller and the obd interface and intend to get the Aussie desert cooler radiator and fan setup

Will post about it once I get it all set up

Steve

[PaulP38a]

oddly enough, I did measure the temp around the engine bay a couple of weeks ago after driving home from work, using one of those hand held laser thermo things.
Temp on top of the fuse box was about 65 degC from memory while the heater pipes were around 80-something.

It was a very hot day (mid 30's), the car is black and it has full bonnet lining.

I am still pondering whether to install a pc fan arrangement in to the fuse box to suck out heat.