bollix
Engines run more efficiently when hot. It also reduces condensation within the block, with resultant acid build up. However too hot an engine can cause premature combustion and also leads to engine mechanical failure such as HGF. The oil can breakdown when too hot, hence oil coolers. It is a fine balance between all the contrary requirements.
here a a couple of quotes from Engins cooling component manufs....
"Race engines have the capacity of operating at much higher efficiencies and power production levels than used at today's limits, but there has been no practical way to accomplish this without causing localized coolant boiling and the resultant destructive detonation. When this happens, the coolant loses it's ability to absorb heat from that particular area of the combustion chamber, developing high temperature spikes. The result is detonation or component structural metal failure."
"The revolutionary designed Davies Craig Electric Water Pump (EWP) is a performance accessory
that improves engine cooling and temperature control, giving increased power and/or improved fuel economy"
hope that helps.
Engines run more efficiently when hot. It also reduces condensation within the block, with resultant acid build up. However too hot an engine can cause premature combustion and also leads to engine mechanical failure such as HGF. The oil can breakdown when too hot, hence oil coolers. It is a fine balance between all the contrary requirements.
here a a couple of quotes from Engins cooling component manufs....
"Race engines have the capacity of operating at much higher efficiencies and power production levels than used at today's limits, but there has been no practical way to accomplish this without causing localized coolant boiling and the resultant destructive detonation. When this happens, the coolant loses it's ability to absorb heat from that particular area of the combustion chamber, developing high temperature spikes. The result is detonation or component structural metal failure."
"The revolutionary designed Davies Craig Electric Water Pump (EWP) is a performance accessory
that improves engine cooling and temperature control, giving increased power and/or improved fuel economy"
hope that helps.
Northern Irelander
Well-Known Member
Good question Dearot....
When you say good or bad, I take it that is good for efficiency and not performance?
I would have to say that an engine is more efficient fuel-wise when hot, cooler temps make an engine run rich but then there is no reason why an ECU could not be re-mapped to suit this lower temperature.
For performance..... a slightly cooler engine would be of benefit, cooler air gives better combustion which gives more Ummphhhh.
On the whole a cooler engine would be less stressful on the engine block, Rimmer Bros were selling some product that you add to the coolant system to make it run a few degrees cooler.
As MHM said the Craig David pump would be best for the KV6, in fact I would fabricate some sort of inter-cooler for the IRD and keep it separate from the main coolant system on the KV6.
"water wetter" is one of the additives. Meant to be good stuff.
dearot
New Member
EWP for KV6 is no doubt the best only if you can the thermostat to open earlier otherwise it still face with thermal shock. I can see the thermostat on my KV6 very late to open as there is much temp different between the top hose and bottom hose of the radiator. it is shocking!
As I am thinking to bypass the thermostat http://www.landyzone.co.uk/lz/f9/dreaded-head-gasket-issue-newbie-39768-7.html, ECU remapping sounds very interesting but what exactly this ECU can do to maintain the same fuel-economy if the temp is lowered?
Northern Irelander
Well-Known Member
Looks good Dearot!! If you are having problems obtaining pipework try some of the plastic fittings and hose connectors from plumbers merchants, the dark grey stuff pressure pipe (metric), not the light grey domestic type (imperial).
You might even be able to incorporate another thermostatic valve on the bypass, depends how much tinkering you need to do.
Regarding the ECU, I would only suggest as a last resort. Basically the injector pulse speeds and duration can be altered to suit, timing, air intake temperature, throttle position etc. A bit like adjusting the jets and floats on an old school carb
dearot
New Member
Definitely I will be needing preferably Y piece 22.4mm (OD) and T piece, 22.4mm 32.5mm. Do you have any LR1796?
Northern Irelander
Well-Known Member
Sorry cant help you there, all out of y and T pieces
rriggs
New Member
Well, that didn't quite come out how I meant it. Try substituing the word cold for the word warm. Makes a whole heap more sense! Guess that's what happens when you try and reply to posts too early in the morning!
Been explained much better by others now anyway so I'll bugger off and stop cluttering up posts with well-meaning but badly typed bollix!
Cheers
Rog
Ideally an engine is designed to run a coolant temp of approximately 102-105 deg C. This helps atomisation of fuel and stops fuel puddling on cylinder walls. The coolant also removes heat from the oil because oils need to work within temp limits.
So really to get the best economy and power its probably best to try and stick to about 102 dec C.
I am new to Freelanders so someone might have come up with this before.
I used to have a Reliant Scimitar ( it did have 4 wheels) it was fibreglass and had a ford essex 3.0 litre engine. As the fibreglass held in the heat they sometimes suffer from over heating. People found that by drilling a 3mm hole in the inner edge of the rim of the thermostat it would always allow some coolant flow round the engine. It did make warm up a little slower but it would also stop thermal shocks.
Might be worth a try? I cant think of any reason that this might cause a problem but you guys are the Freelander experts.
So really to get the best economy and power its probably best to try and stick to about 102 dec C.
I am new to Freelanders so someone might have come up with this before.
I used to have a Reliant Scimitar ( it did have 4 wheels) it was fibreglass and had a ford essex 3.0 litre engine. As the fibreglass held in the heat they sometimes suffer from over heating. People found that by drilling a 3mm hole in the inner edge of the rim of the thermostat it would always allow some coolant flow round the engine. It did make warm up a little slower but it would also stop thermal shocks.
Might be worth a try? I cant think of any reason that this might cause a problem but you guys are the Freelander experts.
dearot
New Member
Thats what I am trying to achieve. some sort of small bypass. in your experience with the hole on thermostat, do you think it will lowered the operating temp? by how much approximately?
A Hole in the thermostat will not lower the operating temp - or at least it shouldnt. What it WILL do, is allow a flow of water past the thermostat, slowing the speed at which the engine gets to operating temperature, because it allows more mixing of the hot and cold water in the system. The operating temperature is a resultant of the amount of heat generated by the engine/gearbox/ird etc and the cooling efficiency of the cooling system. Every one is individual and effected by your driving style.
I believe the problem with the K series lumps (KV6 included) is NOT the operating temperature, but the variation of temperatures around the cooling system and the poor positioning of the coolant temperature sensing. For example the coolant being able to boil in the head area, but the radiator coolant still being cold and the monitoring of coolant temp in the return line from the radiator, not the outlet side of the engine. This also results in a high likelihood of thermal shock when cold water hits hot metal, with prospective cracking, distortion and general nastiness.
Until these design problems are rectified, then at best you can only reduce the likelyhood of HGF and associated problems.
One of the benefits of an EWP is that (with controller system) it pumps in bursts - so it is the duration of its pumping that varies with temperature, not its flow, as per the water pump on the engine, thereby enabling a flow around the system even at low temperatures. It also allows better mixing of the coolant, because it does not rely on a restriction in the flow (thermostat) to alter the flow.
I believe the problem with the K series lumps (KV6 included) is NOT the operating temperature, but the variation of temperatures around the cooling system and the poor positioning of the coolant temperature sensing. For example the coolant being able to boil in the head area, but the radiator coolant still being cold and the monitoring of coolant temp in the return line from the radiator, not the outlet side of the engine. This also results in a high likelihood of thermal shock when cold water hits hot metal, with prospective cracking, distortion and general nastiness.
Until these design problems are rectified, then at best you can only reduce the likelyhood of HGF and associated problems.
One of the benefits of an EWP is that (with controller system) it pumps in bursts - so it is the duration of its pumping that varies with temperature, not its flow, as per the water pump on the engine, thereby enabling a flow around the system even at low temperatures. It also allows better mixing of the coolant, because it does not rely on a restriction in the flow (thermostat) to alter the flow.
dearot
New Member
You are right MHM bu I think a hole in thermostat not only slowing the speed at which the engine gets to operating temperature but it reduces the thermal shock as radiator will not be so cold.
And without a bypass or a hole in thermostat, puting an EWP will not be effective as the hot coolant will not pass the radiator cos thermostat will probably still closed.
I believe the main key to this is lower temp thermostat. if we can install one of this then EWP can reduce the heat soak
And without a bypass or a hole in thermostat, puting an EWP will not be effective as the hot coolant will not pass the radiator cos thermostat will probably still closed.
I believe the main key to this is lower temp thermostat. if we can install one of this then EWP can reduce the heat soak
better still remove the thermostat, but as already discussed - this isnt an easy option, plans are a foot
Northern Irelander
Well-Known Member
Good point about the atomisation of the fuel... although flashpoint of petrol has such a vast range even under pressure. Most of the aerosolisation of the fuel is from the pressure of your fuel pump and injector opening.
I have heard others on MG-Rover.org mentioning 'squish points' on the valve inlets..... How relative is this?? I am not sure??, dont think its been quantified or verified?
Was speaking to a mate last night about the good old days. Another mates uncle (who has long since past away) had a 3.0l Scimitar, he raced the traffic cops in their 2.8i Capri back in the days before speed cameras.
When stopped he was asked what he was up to... to which he told the cop he wanted to see which car was faster, the 2.8 was left for dust.. He he!!
Dearot - I drilled the stat ring as you probably noticed on other threads,6 holes at 4mm is an extra 75.36 mm2 of surface area. On a hot blazing day coming out of work, sitting in traffic the temperature takes a little longer to rise but only goes to about a third of the temp gauge. Before I drilled the stat the gauge was always at just under half way.
I dont have any thermocouples to probe the coolant system with so dont know what the temp of the coolant is in real terms(oC).
However, as soon as I get out of town and hit 50mph on a B road the temp on the gauge drops. On cold mornings when driving at 50mph it can go from third of the temp gauge to the two whites lines on the base of the gauge
. So efficiency of rad, coolant system is dependent on ambient air temperature and air flow over the rad and engine etc.Only drill one or two 4mm holes in the stat ring. I have another spare stat ring to mess about with, going to drill either side of the two supports, hoping this will channel the cooler water around the stat and not through it.
The holes dont increase flow rate (velocity) so to speak but they increase 'throughput' of the volume of coolant. Does that make sense? Pump speed has not changed but volume has.
I have some links (courtesy of MHM, will supply them if you need) about guys modding the coolant system on the MGF and Lotus Elise, I dont subscribe to the gradual/ambient temp variation on the engine causing hgf, more so the initial opening of the stat from cold (initial shock). The MGF cup cars never had a stat fitted and they didnt suffer from hgf until very high mileage. The only reason they failed is because the red elastomeric compound on the OE gasket is crap!!
So if the MGF cup cars had the stat removed, temp fluctuations must have been over a wide range. So howcome they never had hgf until old age?
Have even read that one tech guru reckons that the cooling efficiency of the Rad in the MGF is far greater than what is required of the k-series engine.
The Rad in the freelander is twice the size of that in the MGF so does that make it even more OTT????Attachments
Northern Irelander
Well-Known Member
On the heat soak issue? the EWP is the way to go.
Query - On the KV6 is the outlet from the cylinder block higher or lower than the inlet of the radiator.
In the 1.8 the outlet is lower than the radiator so you will see a small amount of coolant flow by convection after engine shut off. Certainly until the stat closes which causes the circuit to close, preventing further flow, therefore less heat soak in the block.
Sames applies to your domestic water heater going to the header tank in the loft.... son of a heating engineer and all that
Query - On the KV6 is the outlet from the cylinder block higher or lower than the inlet of the radiator.
In the 1.8 the outlet is lower than the radiator so you will see a small amount of coolant flow by convection after engine shut off. Certainly until the stat closes which causes the circuit to close, preventing further flow, therefore less heat soak in the block.
Sames applies to your domestic water heater going to the header tank in the loft.... son of a heating engineer and all that
Northern Irelander
Well-Known Member
notice that the thermostat is a DOUBLE ACTING device on the PRRT! Even more complicated but a step in the right direction regarding HGF.
but a step in the right direction regarding HGF.
