help with cooling the engine bay

[BAV1]

not sure if this is possible or legal (firewall) but any ideas would be appreciated

have been looking at fitting bonnets vents to help get rid of the hot air in the engine bay but worried about excess water getting in would this work and would it fail its MOT or anything

basically adding vents to where the red rectangles are which will then chanel the hot air through existing vent at teh base of windscreen and all water should run in existing chanels

cheers

[BAV1]

cheers wiggy was thinking that but dont really want to hack the bonnet to pieces and add loads of vents as i have plans to add a side mounted intercooler with scoop in the near future and dont want it looking like a scooby

was thinking 2 big holes maybe with a duct running to the top vent to ensure air is expelled using the convection of the air moving over the bonnet

[BUSHWHACKER]

You won't achieve any extra under bonnet cooling by installing vents there.
There's only really two ways to release under bonnet temps without the need for any cutting of bodywork; remove the rubber flaps that cover the gap between the chassis rails and inner wing, or fit a bodylift.

[POPEYE]

You won't achieve any extra under bonnet cooling by installing vents there.
There's only really two ways to release under bonnet temps without the need for any cutting of bodywork; remove the rubber flaps that cover the gap between the chassis rails and inner wing, or fit a bodylift.

Sorry Vince but i beg to differ, he'll release some hot air through there, did'nt think it was a bad idea really, (if ya could make some vents big enough there) it would "deice" the screen to in the winter dont ya reccon? it prob wont make a ton of difference but it'd help'
i have a 2" lift and two bonnet vents and the fecker still get's hot, with both my front fans running i can feel the heat comeing out under the front doors,
got rid of those rubbers as well when i did the lift

[BAV1]

any pics of the vents popeye

may be im just being paranoid but luv the truck that much want to do everything i can to prolong her life and heat is one thing i know can kill the beast

cheers

[POPEYE]

any pics of the vents popeye

may be im just being paranoid but luv the truck that much want to do everything i can to prolong her life and heat is one thing i know can kill the beast

cheers

There are bus roof vents with 12v fans under em,

[BUSHWHACKER]

Having extractor vents at the base of the windscreen won't be all that effective because it's a low pressure area. Thats why the intake for the cabin heater is there. Under bonnet heat will just dribble out at best.
Hot air will only be released effectively when the truck is stationary.

Having rearward facing vents or louvres halfway to three quarters up from the front of the bonnet is the best position as this is a high pressure area where the air passing over them creats a suction effect to draw the under bonnet temps out.

I thought about making an extractor hood, as the Yanks call them, but there's not enough room between the rad and the engine in a Surf..

[POPEYE]

Having extractor vents at the base of the windscreen won't be all that effective because it's a low pressure area. Thats why the intake for the cabin heater is there. Under bonnet heat will just dribble out at best.
Hot air will only be released effectively when the truck is stationary.

Having rearward facing vents or louvres halfway to three quarters up from the front of the bonnet is the best position as this is a high pressure area where the air passing over them creats a suction effect to draw the under bonnet temps out.

I thought about making an extractor hood, as the Yanks call them, but there's not enough room between the rad and the engine in a Surf..

Fair enough mate, actually the bus vents i have are supposed to work like that (i was told at the coach builders) ie- air passing through em draws the air from underneath up,
at the end of the day tho mate i'm betting that whatever one does the engine's going to run at around the same temp, even if i removed the bonnet altogether!, all ya can do is make whatever improvements you can to help the airflow, with all the stuff i've done the engine still runs at the same temp,
BUT the biggest help was converting the backup fan (plus the second one on the front) to a corolla temp sender and altering the electronics so they "run on" after ign's switched off, the number of times i've been out on a shrot(ish) run, put the truck in the garage and minuits later the fans kick in, so heat builds up after the engines stopped, also i've the rad and fan at the rear! you can feel the heat blowing out the rear wheel arches when the fans on, one day i'll get round to wireing the rear water pump to the fans so it'll continue to circulate water untill the fans stop, done about as much as i can regarding hot air, ATF cooler helps as well, and even toyed with an engine oil cooler idea

[shokenore]

Hi All,
first question "POPEYE" one the pic with the under bonnet fan detail what are the 4 round black things with the blue/black cable going to them?
and how is the fan controlled ?

Secondly "BUSHWHACKER"
what sort of mpg do you get and was there a reason for the 4ltr?+how much of s bstrd was the install
the bonnet gas rams look kind of good any suggestions orwas it just a trip down to the breakers?
and yes your engine/engine bay does annoy me somewhat cant you throw a bucket of dirty oily water over it please!

[POPEYE]

the four black things are just LED holder grommets, i fitted blue led's in there fans are just 12v pc fans through a switch (no relay) not powerfull but till i find a couple of decent small fans they'll do, they do push a fair bit of hot air tho and even without em on you can see the heat haze riseing out

this is the wireing i made (with the help of MattF) to run the back up fans (i fitted a second one next to the original plus another on the second rad fitted on top of the chassi above the rear axle, (this was part of the veg oil second tank set up) these fans are controlled by a toyota corolla sensor replaceing the stock surf one, (slightly lower temp setting than the surf and a straight replacement) there might be better/easier ways of doing it but this worked for me and works well, it dose'nt stop the engine reaching it's optimum temp but the fans do bring the temp down pretty quick, you can feel the hot air comeing out from under the truck and out the rear wheel arches,
i did'nt use any of the trucks original fan wireing, junk that and start from scratch, some DTDP switches, 40 amp relays and five pin crossover relays, with these stitches i can have the fans on full auto (off the sender) turn em off altogether, or run em manually

intercooler fan's run on a similar wireing diag but with a CPC thermo switch screwed to the intercooler body, switch is preset at 40 dg break

[shokenore]

thanks for responding,let me get this right with the corrola temp sensor and the switch in "auto" they will run when the sensor says too hot regardless of ignition key position?
i was thinking of using the existing rad fan with a run on timer possibly with a cab switch but independent of ignition key position
switching off the ignition would energise a relay and put power to the rad fan for 3-5 mins after stopping as i have raised the rear of my bonnet i was hoping on getting rid of excess heat thro the gaps
but i think your suggestion including the temp sensor is the way to go
either that junk the viscous fan and fit a aftermarket rad fan kit like off a l**ndy they have adjustable temp settings i think and a run on setting ?
i really do not want to cut the bonnet but may have to am planning for an intercooler but i dont want it looking like a scooby bonnet.

[POPEYE]

thanks for responding,let me get this right with the corrola temp sensor and the switch in "auto" they will run when the sensor says too hot regardless of ignition key position?
i was thinking of using the existing rad fan with a run on timer possibly with a cab switch but independent of ignition key position
switching off the ignition would energise a relay and put power to the rad fan for 3-5 mins after stopping as i have raised the rear of my bonnet i was hoping on getting rid of excess heat thro the gaps
but i think your suggestion including the temp sensor is the way to go
either that junk the viscous fan and fit a aftermarket rad fan kit like off a l**ndy they have adjustable temp settings i think and a run on setting ?
i really do not want to cut the bonnet but may have to am planning for an intercooler but i dont want it looking like a scooby bonnet.

Scooby bonnet
Your correct mate, in auto the fans run on regardless of ign position, this'll work with the original temp sender but i chose the corolla as it's set a few degs below the surfs,
i guess there are other ways of doing it, dunno! the prob was/is that the sensors are permantly "made" till the temp break's the contact (or as a fail safe, the wire breaks or becomes disconnected,
replaceing the viscious fan with a electric "puller" fan is summat i intended to do but never got round to it, matt did do this i seem to remember useing some jaguar fans from the scrappers,

[Apache]

This thread... lots of work and hand-wringing for no good reason IMO.

Maybe I should shout it out...

Fit a tranny cooler!!!!

Its the single best way to reduce the likelihood of potentially damaging coolant temperatures when operating the truck under extreme conditions. If you're not operating under extreme conditions, spend your money on servicing the cooling system so its working as Toyota designed it to, and spend the rest on beer.

Popeye just does all this stuff 'cos he can' and cos he likes shiny stuff.

[shokenore]

i'm not sure i understood you do you mean fitting an transmission cooler will stop all this excess heat "soaking "thro the rad and warming up the coolant?

so you just need an oil cooler plumbed in the lines instead of to the bottom of the rad,and tucked away from any spinny/up downy bits?
do you have one on your truck?

[Apache]

Yes I have one. With a wee intercooler fan so I can cool it when there's not much airflow (moving slowly offroad, where engine / gearbox loads can be high)

There are numerous ways of implementing it. Mine is inline with the cooler in the rad and removes excess heat from the ATF before it goes into the rad cooler. I did it this way because overcooling ATF isn't a good idea either. Therefore when the tranny is under heavy load, the excess heat is dumped via the add on cooler, and if its been overcooled, running it through the rad warms it again to near optimum temperature.

If you do a search, its a fairly common mod.

Just removing hot air from the engine bay wont make a huge difference - as Popeye has said and he's really gone for lots of cooling. The rad is where the engine dumps 99% of the heat, not the engine block.

I cant see much reason for cooling when the engine is stopped either. It doesn't get hotter when you stop, it just doesn't cool as quickly.