Questions About Water Temp And Thermo Fan Setup?

[BrynDETT]

Hey everyone, car is tuned now .. everything seems to be going ok except for the water temp.. i have let it get as high as 98 degrees...i went and bought some of that "redline water wetter" yesterday. the $50 stuff.. and it seems to keep it lower until i get up the car for a bit..

now i think i know what the problem is.. just wanted other ppls opinions ... the guy that wired my ecu, wired the fans onto the wrong output, so the tuner could only have them "on" or "off".. so thats the way they are atm, allways on...

would this block airflow at high speed? i suspect it would? as the fans are on the front of the radiator as they would not fit in the engine bay..

s13 with r34 rb26

mspec alloy radiator

cant remember model numbers but, they highest powered 11" spal pushers i could buy from pwr

thanx

[TiTAN]

have you thought about using a larger radiator as it shouldn't matter if the fans are always on even at high speed.

[Ad's]

How old is the thermostat? Im asuming you replaced it when you changed the motor over?

[KiwiRS4T]

Get this (or one like it):

http://www.skylinesdownunder.com/forums/showthread.php?t=62845

[BrynDETT]

thermostat is brand new, though im not sure wat temp it is, just bought one from global... might try a low temp one...

and to titan: u wouldn't think that 100kph air would be better then what the thermos push? im not sure if wind would get through the thermos without to much turbulence? ..

[zebra]

Fans on the front of the radiator block airflow at high speed.

Also having an RB26 jammed in an engine bay designed for a 4 cylinder isnt going to help.

[discopotato03]

From most I've seen smallish paired elec fans don't cut it . The successfull method I reckon is to use one large fan even if its diameter is slightly greater than the height of the radiator core .

As for triggering the fans many tend to forget that the water temp in the RADIATOR is critical and must be lower than what you want to run the engine at to regulate properly .

Its the engines thermostat thats intended to set the engines lowest temperature not heighest so provided the radiator can keep the water in it cooler than the thermostats opening temperature the system will regulate temperature properly .

If your cooling systems capacity is a bit lacking then the best you can do is to run the fan/s all the time or have a thermo switch located in the radiator set low . Remember its the reserve of cool water in the radiator that allows engine cooling when the water thermostat opens right up . If the rad water temp is high then the hotter water can't cool the engine can it .

A six cylinder in an engine bay designed for a four is always a drama because theres no room for a clutch fan and the cramped bay often gives a poor flow path for the hot post radiator air . All the huge radiators in the world make little difference in these situations because if air banks up in the bay it won't flow well through the core resulting in poor heat transfer .

IMO same old same old , RWD R32 better platform for any RB engine than a Silvia and the better big capacity route for an S13/14 is the KA24DE engine like Nissan used in USDM S13/14's . Better fit , better cooling , better weight distribution , heaps of turbo conversion gear available in the US - and its all a known quantity .

Bottom line is a Silvia is not a baby Skyline and there are no factory solutions to this six into four hybrid .

A .

[Simon-S14]

fwiw i have a rb25 in my s14 and i managed to fit the clutch fan in there. engine mounts were modified tho to move engine back and lower by 25mm in each direction. i used an R31 fan hub which is the shortest of all nissan hubs. it all fits tho.. but only with a stock rad and shroud. which i seem to have solved my cooling issues with instead of using the shitty ISC rad with no shroud (wouldnt fit)

[BrynDETT]

hmmm so by the looks of things its pretty f**ked haha... i might just get the fans rewired and see if anything changes... i take it every silvia owner with a 6 cylinder has overheating issues? would spacign the bonnet help?? any other things to try?

[zebra]

Lifting the rear of the bonnet makes it worse 99% of the time, creates a high pressure area at the rear of the engine bay and makes airflow worse.

I would dissconnect 1 fan and go for a drive, might help with airflow through the radiator when driving.

Oh BTW do you still have a/c?

[BrynDETT]

kk will try the one fan thing... when i can as the car is down at my mums.... and i dont have ac.. does that make it worse?

[eightsixboy]

There pretty small fans 11's. On my 31 i ran a 14 and a 10 on a 52mm alloy rad and it was only just up to scratch with cooling, even then in summer it couldn't cool down the motor below 85c.

If you have room run a standard viscous fan with a shroud. I learnt the hard way the thermos are generally pretty crap.

Are your fans front or rear mounted? If there mounted in front of the rad i would put them behind and have them pull the air through, pushing it through isnt the best setup.

Also a proper fan shroud around the fans would help alot, you'd be surprised how much the shroud actually does in directing the air through, i think thats why my old setup wasnt that great.

[BrynDETT]

2 11" fans where the only ones i could fit.. couldent fit 1 16"... they are the most powerfull 11" blowers spal make...or so pwr told me.. they are mounted on the front of the rad.. there wasnt even enough room in the engine bay for the spal slimline ones...so deff no viscous fan... i have 38mm from rad to pulleys... so its pretty tight in there...

[NSNPWR]

May seem obvious, but they are pushing and not pulling yeah?

[KiwiRS4T]

^^^ you wouldn't be the first! fans are normally set up to suck air through the radiator so if you have them on the front has the direction been reversed? No aircond should be a help. And shrouds are a must even if you have to custom make them. And fit a thermo switch - its not too hard. Also get an air diverter if you haven't got one already.

[NSNPWR]

Exactly...easy enough to get wrong and even easier to correct!

Get a piece of paper and place it on the engine side of the radiator core...if it sticks, your fans are going the wrong way!

As has been said above, shrouding is a must, I've managed to get a single 16'' fan in the original 32 GTR shroud, got this working in conjunction with the air con fan...also have a diversion plate...all seems to work well.

[BrynDETT]

fans are deff blowing ... but since the fans are on the front of the rad.. wouldent it be worse to have a shroud? coz then no other air besides wat the fans are pushing in could get through...

and Kiwir24t.. what is a air diverter? i have a bit inbetween the headlights, is it that?? hmm ill post a pic

EDIT: ths bit behind the grill****

Edited April 24, 2011 by BrynDETT

[KiwiRS4T]

Like this (mine has a scoop to direct air to the snorkel):

[BrynDETT]

yeah.. looks to be pretty much the same thing as mine

[wlspn]

Yes, that is an air diverter. In most cases a lot more can be done for engine cooling...

Make some custom ducting so all air coming in through the front bar can ONLY go THROUGH the intercooler & radiator, not around it at all. So loke a divertor but top, bottom & sides...

If necessary use foam beside the rad to get the best seal you can