V8 into series 2/3

[Jon White]

does it actually boil over, or just show hot on the gauge?

[Jon W]

I haven't let it get as far as boiling over, just gets hot on the gauge

 

 

[Arjan]

You better get an IR gun to test the temperature as the gauge could be wrong..

 

[L90-v8]

your switch for the electric fan needs to be in the top hose or in the top of the manifold because the bottom hose is cold and the top hose is hot

also you can fit a 82 degree stat that will help keep her cool

[L90-v8]

also you don't need to modify the rad you can use the overflow pipe by the rad cap an put it into a expansion bottle/ expansion tank 

when the coolants hot it will expand into the bottle via the rad cap when the coolant cools down the coolant will go back into the radiator keeping the radiator full at all times

[L90-v8]

4 hours ago, Arjan said:

You better get an IR gun to test the temperature as the gauge could be wrong..

 

absolutely agree

[Jon W]

35 minutes ago, L90-v8 said:

also you don't need to modify the rad you can use the overflow pipe by the rad cap an put it into a expansion bottle/ expansion tank 

when the coolants hot it will expand into the bottle via the rad cap when the coolant cools down the coolant will go back into the radiator keeping the radiator full at all times

I already have the standard expansion bottle setup from the series 3 which when pressure builds lets waters into the expansion bottle. so I don't see how the pipe indicated would work by putting that into the overflow pipe, as it will constantly overflow from the system surely as there will be a constant flow as the system is no longer sealed/pressurised.Or have I got the wrong idea about the pipe indicated.

i have thought about moving the stat for the fan but have read into it and there is always a mixed opinion about its position. Bottom hose at least shows rad is working and will kick in with a lower temp stat when radiator cooling isn't sufficiently. Top hose is likely to cause the fan to run constantly with hot water running out the top of the engine

 

Thanks 

 

Jon 

 

 

[RobotMan]

Stat at bottom would need to be set much lower to function correctly. 88° out of the radiator is way too hot considering that's the temperature it's supposed to go in at.

[Bowie69]

1 hour ago, L90-v8 said:

your switch for the electric fan needs to be in the top hose or in the top of the manifold because the bottom hose is cold and the top hose is hot

also you can fit a 82 degree stat that will help keep her cool

Neither of these things are true I am afraid, the stat does not dictate the cooling capacity of the radiator, us, once it is open, it is open.

Plus, the switch in the bottom hose is fine if you rate it properly, there are many options when it comes to switching temperatures.

 

[L90-v8]

fitting a lower degree stat wont change the capacity of a cooling system at all but fitting a cooler stat it will open sooner reducing the temperature    the hoter stats are designed to keep the temps up reducing emmisions 

[L90-v8]

Just now, L90-v8 said:

fitting a lower degree stat wont change the capacity of a cooling system at all but fitting a cooler stat it will open sooner reducing the temperature    the hoter stats are designed to keep the temps up reducing emmisions 

fitting the fan temp sensor in the bottom cold hose is madness every vehicle I know of has the sensor in the top of the rad or in the stat housing 

[L90-v8]

2 hours ago, Jon W said:

I already have the standard expansion bottle setup from the series 3 which when pressure builds lets waters into the expansion bottle. so I don't see how the pipe indicated would work by putting that into the overflow pipe, as it will constantly overflow from the system surely as there will be a constant flow as the system is no longer sealed/pressurised.Or have I got the wrong idea about the pipe indicated.

 

 

Thanks 

 

Jon 

 

 

ahh soz I get what you mean theres a pipe blanked off on the inlet manifold i should have read correctly    I think mine is piped up from the inlet manifold to the top o/s/f corner of the rad 

[Bowie69]

33 minutes ago, L90-v8 said:

fitting a lower degree stat wont change the capacity of a cooling system at all but fitting a cooler stat it will open sooner reducing the temperature    the hoter stats are designed to keep the temps up reducing emmisions 

If the radiator is sub-spec it will still over heat even if you had no stat in it.

Just need Simon from X-eng to wade in on the fan switch as he produced them to fit in the bottom hose.

If you think about it, if the radiator is way over capacity, then there is no point switching a fan on because the engine is at 90C when the water coming out the radiator is at 40C.

[L90-v8]

16 minutes ago, Bowie69 said:

If the radiator is sub-spec it will still over heat even if you had no stat in it.

Just need Simon from X-eng to wade in on the fan switch as he produced them to fit in the bottom hose.

If you think about it, if the radiator is way over capacity, then there is no point switching a fan on because the engine is at 90C when the water coming out the radiator is at 40C.

I understand if the rads not upto the job its never going to keep cool

ive only ever come across an used top hose fan switches if the x eng switch is designed as a bottom hose switch an comes on at a lower temp all should be good but if you fit a higher temp switch from say a fiesta an put that in the bottom hose its gonna cook I would have thought a switch set to 88 should be in the top

from what I read his fan is not coming on till past 100 deg that indicates to me the switch is either faulty or set incorrectly or not designed to be in the bottom hose or the temperature gauge is not reading correctly

[Bowie69]

Check the temps with a gun and chuck a lower temperature switch in.

Actually, the switches are often two way, with different temperatures on each terminal, perhaps you have it wired up to the secondary higher temp?

[Jon W]

Engine stat is a low temp 74c, fan switch is now lower coming in at 84 and off at 79. So that the engine stat stays open, the other option is 82 and off at 68 but this would mean the fan would run and the engine stat would close.

have taken the rad out and will get an addditional port fitted. Then try it with the new fan switch, and also test the gauge and things .

When the fan dose come on it does cycle on and off so fan is moving the heat 

 

Thanks 

[Snagger]

17 hours ago, L90-v8 said:

fitting the fan temp sensor in the bottom cold hose is madness every vehicle I know of has the sensor in the top of the rad or in the stat housing 

Completely wrong.  The fan switch goes in the bottom hose so that the fan is only triggered if the rad needs assistance.  Having it in the top hose means the fan will run continuously as soon as the engine warms up, and will do so for some considerable time after shutting down, flattening the battery.  Only thermostatic switches for aircon booster fans and compressor clutches go in the top line, usually in the themostat housing or elbow, and they are set at much, much higher temperatures looking at engine temperature, not incoming coolant temperature.

[Snagger]

15 hours ago, Jon W said:

Engine stat is a low temp 74c, fan switch is now lower coming in at 84 and off at 79. So that the engine stat stays open, the other option is 82 and off at 68 but this would mean the fan would run and the engine stat would close.

have taken the rad out and will get an addditional port fitted. Then try it with the new fan switch, and also test the gauge and things .

When the fan dose come on it does cycle on and off so fan is moving the heat 

 

Thanks 

That won't be an issue if you put the fan switch in the correct bottom hose, as the coolant leaving the rad should be much cooler.  Only if that coolant is still hot, because the rad isn't getting enough airflow, will the fans then be triggered.

 

[Snagger]

16 hours ago, Bowie69 said:

Check the temps with a gun and chuck a lower temperature switch in.

Actually, the switches are often two way, with different temperatures on each terminal, perhaps you have it wired up to the secondary higher temp?

I have an X-Fan unit, and that is exactly what it does - three terminals, one input and two of them (parallel) for different temperature triggers, allowing a main and a booster fan to be powered from one switch.  It's a very simple and neat installation.

[L90-v8]

4 hours ago, Snagger said:

Completely wrong.  The fan switch goes in the bottom hose so that the fan is only triggered if the rad needs assistance.  Having it in the top hose means the fan will run continuously as soon as the engine warms up, and will do so for some considerable time after shutting down, flattening the battery.  Only thermostatic switches for aircon booster fans and compressor clutches go in the top line, usually in the themostat housing or elbow, and they are set at much, much higher temperatures looking at engine temperature, not incoming coolant temperature.

my sensor is in stat elbow an works perfectly fine it will get up to temperature without the fans coming on early an certainly don't keep going an flattening my battery it cuts in an out as necessary in traffic  

I guess its each to there own where you put it  I have put the sensor in the top for years an will carry on doing it this way as I have never had a issue  most of the standard factory cars ive had have also been installed this way until they started controlling the fan via the ecu

[L90-v8]

[L90-v8]

as long as the sensor has the correct temperature settings on and off it don't matter where you put it I personally prefer the top but that's my preference

22 hours ago, L90-v8 said:

ive only ever come across an used top hose fan switches if the x eng switch is designed as a bottom hose switch an comes on at a lower temp all should be good but if you fit a higher temp switch from say a fiesta an put that in the bottom hose its gonna cook

 

[Snagger]

Having the fan switch in the top hose means the fan will come on when the engine is hot, even if the radiator is bringing the coolant temperature down far enough to do its job.  Setting the switch temperature higher to stop the fans coming on at normal temperatures means that it only activates when the engine is already overheating, as opposed to only when the rad is in need of assistance prior to overheating.  It sounds like semantics, but it isn't.  Having the fan trigger in the top hose is bad engineering.  Having the ac clutch cutout trigger in the top hose makes sense enough and likewise the booster fans, as you only want those triggered as a last resort to prevent engine damage, the main fan already trying to control coolant temperature.

As you say, though, the most critical thing is to not put a top hose sensor in the bottom, as that will end up very expensive.  Top hose sensors will work, but they will allow much greater exceedance from the normal engine temperature if they are not to run all the time, and will run on longer after a hot shut down due to convection in the block.

[FridgeFreezer]

On 03/06/2017 at 0:39 PM, Snagger said:

Having the fan trigger in the top hose is bad engineering.

When making a statement like that about how the factory did something, there's two possibilities: You are smarter than the huge teams of professional engineers at multiple car companies with all their test facilities, years of R&D, and banks of supercomputers. Or the 2nd.

[Snagger]

Let's be honest, a lot of the engineering is cost engineering, which is not to do with quality or reliability but making stuff cheaper to produce. Some of it must make the initial design engineers cry.   Open ends on chassis outriggers but no drain holes, stopping galvanising body capping and painting after fitting them, plastic head dowels, plastic expansion tanks, low quality engine earths... the list is long.