View Full Version : engine bay temperatures
does anyone have any figures of mk1.5 engine bay temparatures?.. with v6 or turbo installs..
im trying to work out which thermostatic switch is good for my engine bay lid fan .. here are some approximate switches available from RS components. They are all 10amp rated which should be enough for the standard engine bay fans, unsure yet if it will run a spal as they sometimes draw more than 10amps. they are N/C configuration, so plum one inline on your positive fan feed, and it will stay off until the temperature rises to the following figures.. once the bay temperature reaches the figures below, it turns the fan on, yes :).. and it will turn it off once the temp has reached 15 degree centigrade lower (approx). f'in handy things at the amazing price of 2-3 quid!.
15
20
25
30
35
40
50
60
70
75
80
90
100
120
130
140
150
160
180
200
220
250
in them kind of steps from 15-250 i believe, heres an example:
go to www.rswww.com and enter part number : 339-291 http://www.twobrutal.co.uk/forum/images/recovered/2007/01/1.gif
im a bit stuck though as i cant measure the temps yet!, has anyone got a infrared thermometer they can throw in the bay after a run and at idle..? what temperature woud you use?.. im edgeing towards lower temps like 25-40 degrees... inlet air temps will be around this in summer.. and thats when i want it to take out the hot air from the bay so it helps not increase the inlet temps too much...
Marksman
01-01-2007, 20:06
Why not us an adjustable one Adam? Or even a complete kit designed for the kit car industry? I know it's not really the TB way but if the work has already been done for us...
O.S.
i know mate, but im tight! .. these thermos are only £1.85p :poke2:
Marksman
01-01-2007, 20:14
:slap:
Fairy snuff though!
Owen.
im buying some platinum resistance thermos for the intercooler :mrgreen:.. a mere few quid each 8O and lightning reaction times. they need bonding onto the inside of the IC piping with a thermo-transferring sticking compound.. cant roll the name off my tongue..! :?: ive chosen them for the IC fan #2 and meth injection signal. downside to such trickery is you need something to measure the plat resistance and switch from reading the data, that parts hexpensive! (boo)
i could run the lid fan from this set up but i want it independent. engine bay fan and just one of the Ic fans will be on permanent.
gone for 40 degrees :shrug:
Marksman
01-01-2007, 22:59
You could come over all grey and nerdy...
Errrr, weeel it's mid July whereby the historical ambient temperature is 19.7666643 deg. C, and I'll be using light to moderate acceleration so I'll fit the 78 degree thermostatic switch, but if that proves unsatisfactory then I'll stop on the A4379 and change to the 78.5 thermostatic switch providing of course that my tartan travel blanket doesn't slip off my knees inwhich case I'll have to go out on a limb and stretch all the way to the 79 degree model :rozzer:
Sorry (a bit)
Owen.
i know what you mean owen, but im sure in winter the engine bay temps wont call on the fan at road speed, and same for ic fan #2 etc etc with icy cool temps flowing about. adjustable in this case would be a pain in the aris.. just hope i have picked the right temp.. i reckon the engine bay temps will be over 25 on an average day easy.. above 40 even, what do you think...
isnt ambient music?
Marksman
01-01-2007, 23:41
Only playing Adam!
I agree, I'm sure you'll see temps above 25. TBH I'm not sure what an ideal engine bay temp is. Your IC isn't in there anyway so I'd have thought that anything left will be happy at moderate temps and maybe even prefer not to be too cold. Where id your intake BTW? If that's in there then the cooler the better but if not then maybe warmish might be good and blasting too much cold air might be less good? Dunno really, just waffling till someone who has a valid opinion turns up!
Owen.
intake will be top corner above the gearbox, only room for it i'd guess, aside making it a cabin hoover :poke2::mrgreen: ... i dont know is basically the answer to questions :) when paff comes down in his mk1 i can have a rough probe about in his bay if he dosent mind ...
Is it not a normally open switch that you want to use?
Using a N/C switch will mean that the fan is on all the time untill the preset temp is reached and then it will switch off.
Link doesnt work as session is timed out, do you have the RS part number?
Ad, I've got an infrared thermometer I can throw into the bay for you but it'll be on a 4AGE. Will do it tomorrow for you.
hello murf, thanks for pointing that out the dead link mate.. heres the part number :
339-291 http://www.twobrutal.co.uk/forum/images/recovered/2007/01/1.gif
reading the statement at the bottom i think says it turns on as the temperature rises then go's off when it drops 15.. confusing sometimes!
Ad, I've got an infrared thermometer I can throw into the bay for you but it'll be on a 4AGE. Will do it tomorrow for you.
marvy jasper.. that would be ace, after a run , and at idle, measure outside ambient if poss aswell :thumbsup:
lodgeman
02-01-2007, 00:22
Ad, I've got an infrared thermometer I can throw into the bay for you .
why doesnt that surprise me!!!!:rofl: has nikki dug up the front garden for that new driveway yet?:hidesbehi lol
dont forget i still have your discs!!
It's so I can monitor the temps of my tree frogs & poison arrow frogs.
And stop trying to cause trouble lol, had earache all over Christmas about the driveway. She reckons we don't need a bigger one if I got rid of some cars...
Yup, I'll try to collect the discs this week, if not then deffo at the weekend. Thanks for baby sitting lol
how many cars do folk need ?! you lot..tut!
how many cars do folk need ?! you lot..tut!
Hmmmn! Let's see; Clio, 1.5 (in progress) & I suppose the missus has got one lol
It is confusing but going by this
N/O types close on temperature rise
You'll need a N/O switch.
Paul Woods
02-01-2007, 07:32
remember the engine bay fan is only there for sitting in traffic jams type scenario....it does pretty much jack when you are on the move as the force of incoming air through the vent even at 30mph way exceeds the fan.....it only ever comes on with the 4a-ge installed when things get very hot stood idling on a hot summers day.
I wire them permenantly because a 3s-gte tends to get very hot in a mk1 bay even in the widdle of minter,you may find it'll stay on 90% of the time on a switch anyhoo...unless its a very high temp one in which case thats defeating the O.
aye paul, can remember the fan coming on in traffic, good point!. maybe ive been too shy with the temperature, its looking like i'll end up with a stack of thermos spare :freak3: , but all good fun testing. jaspers probing will help no end. we might even have a genuine rough figure later, theres a first on a forum lol.
murf cheers for that mate, ive prolly fecked up then :) i'll test it when it arrives. its confusing to me for sure.. i buy pneumatics alot of the time at work and n/o means the flow of air is flowing and port is open it starts its mechanical position 'open'. n/c means the flow has stopped (it starts in the off position) and switches to open.. respectively. why the sod are electrics opposite logic!?
with electronics youre referring to the contact itself (open/closed)..with pnuematics it seems to refer to flow..
when two disciplines meet..!!!
Need to remeber than about pneumatics!
Niks right, with electronics/electrics normally open means that when you take the part out of the box and theres no power applied the contacts are open and no power can flow through the switch.
Paul, youve wired the fan on mine to extract the hot air. Would it be worth fitting a switch to cut power to the fan when driving as the fan will be fighting against cold air coming in.
I'd test the temps on mine for reference but ive got the inlet manifold etc in bits at the mo :)
my bay fan and ic fan are on permenantly..too much hassle and not really required to have either on a switch imho..
though if yours is pulling against the flow (bit odd) then i would run a swtich to the dash..or better still use the speed feed (purple) to the ecu so it turns off when moving..
Paul Woods
02-01-2007, 17:11
murf the fan working in the other direction doesnt seem to affect it,air still gets blasted in around the engine when driving,i know this because i monitored temps around my 1.5's bay with an equus digital probe and it made no difference at all if the fan was wired to suck or blow.....as i say at speed the fan just gets blown by....but you do need it to blow and extract heat from the bay at a standstill....as nik says no need for switches n the like....on with ignition works fine (fuel pump feed so it only runs when the engine does).
Mission Failed:
This was the thermometer I used, the TN1. It has an operating range of -22'C to +110'C. The distance to target ratio is 1:1 therefore the thermometer should be positioned as close to the target as possible without the need to touch the surface being measured:
http://www.fluesystems.com/thermometer/info/tn1_thermometer.htm
Well pissed off, on this site it's £16.80 (ex. VAT), £19.74 (inc. VAT) and they have a price match guarantee to beat any competitor's price...I paid £29.99 from a reptile suppliers! Bah!
But I think the TN2 is needed, range -33'C to +220'C
http://www.fluesystems.com/thermometer/info/tn2_thermometer.htm
Back to the job in hand:
Outside air temp: 8.1'C
After 5 mins idle (before drive), reading taken at manifold:
Hi (temp out of range of thermometer).
Reading taken at engine lid level:
65.9'C
After 20 mile drive, motorway apart from 1.5 miles to motorway & back. Revved it's little ass off, reading taken at manifold:
Hi (no surprise there)
Reading taken at engine lid level:
109.9'C
Didn't bother to take an idle reading after drive as the first idle reading was showing out of range.
Therefore your 40'C switch will mean it's going to be permanently on so you may as well throw your thermostatic switches away and wire always on....Then again, the 2 was stationary when the temps were taken so obviously no air flow....Basically, it's up to you lol
Sorry I couldn't be a bit more specific on the temps.
fantastic mate :praise2: ..more specific?.. thats the first temps ive seen of a bay and not some nonsensical estimate prostituted across a forum by an armchair mechanic!. :roll: :blush:... really.. thanks for doing that jasper.. i owe you one :beer:
now we need some more figures to cross reference. they are pretty high indeed, especially 110 degrees after a thrash.. thats like an oven!.. hmm.. im getting a grasp of how hot it can become.. which begs the question if thats the 4age.. what is the turbocharged ambient!?. must be above that.. anyone has any genune gauged temps of any mk1/mk2 bays bung them on this thread please
looking at 66 degrees at idle for an ambient of 8. push that upto 25 degree summer ambient.. it must increase at least another 17 degrees to 82 etc. thats hot for idle in the bay!.. and the rest etc
No worries Ad, always happy to help out.
I was trying to take the reading at the manny (virtually on top of it) but was way too hot for the thermometer so just gave a reading of Hi which means it's out of range. When I came back to the engine lid height, which is where I presume your fans will be, that is where I managed to get the readings.
Hot indeed!
hopefully your frogs wont be getting high lol
it is hot..cant believe it really!.. if only the temp could be gauged while its moving at speed :banghead:.. got to drop some good numbers i would have thought..
hopefully your frogs wont be getting high lol
No, but you will if you lick them lol
it is hot..cant believe it really!..
Does seem hotter than I expected. Took the reading a number of times just to make sure and each time I ended up with the same result, give or take a deg or so.
if only the temp could be gauged while its moving at speed :banghead:.. got to drop some good numbers i would have thought..
You could always sit on the back whilst I take it for a spin, just hang onto the spoiler and you should be ok lol
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