X-flow / zetec waterpump flow rate.

[Nigel Riches]

Ok, long shot here, however, anyone out in 7 ownership know what the difference in water pump flow rates are for the two engines in the title. 

Trying to get more info so as to decide which course of action to take in getting the engine cooling under control. 

Regards, Nigel. 

[Molecular--Bob]

Cooling is generally not a problem with zetec instalations, getting them to run warm enough can be. Can you describe how you have yours set up? Are you using the Ford thermostat housing or a water rail? The stats have a habit of sticking in the Ford housings which can lead to all sorts of wierd results.

[CaterBram]

Nigel, are you getting too much cooling or running too hot,

I had cooling issues for a couple of years, it eventially came down to oil windage as i'd got a rubbish sump.

If you are wet sumped and not using a decently baffled sump with windage tray then this couple be a problem.

[Nigel Riches]

Thanks for your comments. 

Some more info here, the engine is standard 2l blacktop zetec, fitted with Raceline water rail, alternator kit and ali sump, also has Raceline 4 - 1 exhaust system, fuelled by Jenvey 45 tbs, I also splurged on their coolant hose kit. 

The radiator is not new, however I did have it checked by the local rad man, who gave it a clean bill of health, it is the Caterham radiator for use with the 2l Vauxhaul engine, so capacity should be ok, never had a problem with cooling the x flow. Strange. 

Whilst the car is moving through the air the engine temperature is stable, and presently around 70c that's the latest thermostat I have tried. Don't think this is thermostat related. 

I set the fan on / off temperature in the Emerald K3 to 92 / 87, and when the ambient temperature was only 15c, and the car was idling in the garage, with the bonnet off, the fan cut in and out ok. 

However, when the ambient temperature was back around 30c the fan cut in, but didn't ever get to the point where it would cut out, but in saying that, the temp gauge on the dash was still below the centre, 90c, mark, (old Smiths gauges, circa 1982, like most of the car), so my thinking is, the fan (9" Spal electric, direct from battery, via ECU controlled relay) isn't drawing enough air, rated at 1010m3/hr. 

I have done some measurements of the radiator fin area and find there is sufficient width to mount two smaller (6" dia) fans side by side, the combined airflow from the fan types I have found would be 1240 m3/hr or the gruntier fans would shift 1480 m3/hr, so approx 19% or 32% increase in airflow, not sure at this stage if there will be sufficient clearance between the rad and the anti roll bar for the greater flowing type, still, after all the other little problems that have been overcome, this isn't a big one. 

But back to my header "water pump flow rates"  I asked this as one of the blokes I work with is ex motor trade, he knew of various Holden (Aussie Vauxhaul) engines where the coolant was pumped around at such a rate it wasn't in the rad long enough to lose heat effectively, got me wondering if something similar is happening here. 

Any more information would be gratefully received. Many thanks. 

Nigel. 

 

[Klunk]

Hi Nigel,

Change the thermostat back to standard (85-87c?) - you will end up damaging the engine as the oil won't be up to temperature.  Zetecs run quite warm at around 90c.  With this in mind your fan is not going off as your off is at 87c.  Change the on to 97c and the off to 92c as a starting point.  A zetec is in the 'red' at about 110-120c!  

Regards,

Giles 

 

[Klunk]

Regarding the water pump, do you have the extra pulley to ensure the pump runs in the correct direction? If you got the package from Raceline I imagine you will.

[CaterBram]

Agree with Klunk, normal oil temps around the 100 Deg C, upto 120 Deg C Max.

Have you got an oil temp gauge (or switch between two senders for oil/water)

 

 

[OliverSedlacek]

The thermostat is too cold, 70C is too cold for the oil to do its job. If the engine is actually running at a good temperature of 90C, I'm not sure you have a cooling problem at all. The trip temperatures for the fan should obviously be higher than the thermostat temp if you don't want the fan running al the time.

[Drumster]

Pretty certain my thermostat is 82deg with 92/87deg thermo-switch. 

(Raceline Zetec - same set up as you) If you search the archives you'll see I had a cooling problem (overheating in standing traffic but fine on the go) with the Caterham Ford aluminium rad fitted with a 9" Pacet fan. Decided to get a Radtec so I could fit an 11" Spal fan.

On both scenarios the fan kicked in at 92 but the 9" fan wouldn't bring the temp down in fact the temp continued to rise until the car got moving again. With 11" fan the temp drops to 87 very quickly.

[Jonathan Kay]

But back to my header "water pump flow rates"  I asked this as one of the blokes I work with is ex motor trade, he knew of various Holden (Aussie Vauxhaul) engines where the coolant was pumped around at such a rate it wasn't in the rad long enough to lose heat effectively, got me wondering if something similar is happening here.

I think that heat transfer in a conventional set-up always improves with higher flow. (And that you can show it with a thought experiment... )

I wonder if what they had observed was something to do with controlling pressure with orifices and the presence or absence of a thermostat.

Jonathan

PS: What OliverSedlacek says.

[Nigel Riches]

Thanks gentlemen, I have some quality time in the garage booked over the weekend, as SWMBO won't be here for most of Saturday  . 

I will reinstall the hotter thermostat, and recalibrate of the fan on  / off point, luckily I bought a sheet of gasket material, and have cut several thermostat housing gaskets for this exercise. 

Just as an aside I researched the 2l Vauxhaul motor power, seems it was only 95kw, and that was the JPE car, so the radiator I have is now under specified for the 127kw zetec engine, but of course those figures are at max chat, my cooling problem is manifest at much more mundane power levels. 

I looked at the Radtec website, nice kit, nice price, depending on which side of the counter you're standing, and a fair few threads in BC about leaking, not what I need down here.

So my quest for a resolution continues, there is a company very close  to where myself and handbrake will be going for Easter, they make radiators from scratch, they manufactured the oil coolers for the Hawker Hurricane P3551, which was restored to flight in 2000. There will be a visit to see what they can offer. 

Other problems need addressing also, a bit of the old "flog on rewardless" comes to mind. 

I did have a bit of a laugh at the words the predictive lexicon wanted to use, oh dear, stay behind after class and learn the nuances of the English language. 

Regards, Nigel. 

[Jonathan Kay]

The cooling system of the Hurricane provided additional thrust... I wonder if ACBC ever thought about that...

Jonathan

[andy couchman]

Interesting - thanks Jonathan.

Looking at the Meredith effect (incidentally, can't see why antifreeze makes any difference to the effect - and what about Evans!) If you run your 7 with the cooling fan running (regardless of temperature), given that some/much/most of the air exits through the bonnet louvres, would that create any thrust effect?

As the fan has to be driven through the battery, which itself is powered by the alternator, which in turn absorbs some engine power, would you get the best effect if on needing maximum acceleration or speed you:

1. Switch off the alternator.

2. Switch on the cooling fan.

Or would the losses mean that the effect would at best be negligible?

I'm not an engineer so may just be talking through what I should be sitting on...

Andy

[Jonathan Kay]

Looking at the Meredith effect (incidentally, can't see why antifreeze makes any difference to the effect - and what about Evans!) 

I don't know why they wrote it as they did, but I'd make a guess that they knew about the fascinating and important history of cooling the Merlin in the Spitfire, and were thinking about evaporative cooling not beng used eventually.

Typical current for a small cooling fan is 5A, say 60W, so maybe 100 to 200W for the whole circuit from alternator to fan.

I can't find the the power needed to run an alternator (not the current generated), but it must be trivial compared to that needed to support typical electrical loads, and the system is very inefficient.

Not powering the cooling fan or spinning the alternator will release some power that can get to the wheels,  but avoiding electrical loads on the alternator is probably much more important.

2. Switch on the cooling fan.

I don't understand this: more please.

If you run your 7 with the cooling fan running (regardless of temperature), given that some/much/most of the air exits through the bonnet louvres, would that create any thrust effect?

Nope. The power is too low and the airflow too disorganised. Getting any significant ram effect from the cooling system is very complicated. But has it been used in eg F1?

Jonathan

[OliverSedlacek]

5A is pretty low for a cooling fan! I measured some for a mate recently (used on a Ferrari, two per car, one each side) because he wanted to know if the race fan was actually more powerful than the road fan. The race fan drew 21A and the road fan drew 17A. As for engine loading by the alternator, the magic conversion factor is 0.02 BHP per amp (give or take a bit on the estimate of alternator efficiency).