Home > Puma (Tdci) > better fuel cooler |
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Jonno Member Since: 06 Mar 2012 Location: Yorkshire Posts: 234 |
personally I wouldn't have thought it would be that worthwhile fitting extra fuel coolers, I can only see the tank heating up significantly on warm days and when the car has had a very long run and the tank is not full.
Also what would you use to cool the fuel? The coolant is pretty hot and the oil more so. Jonno |
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3rd Nov 2013 4:41pm |
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munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558 |
the coolant already cools the fuel ( coolant to fuel exchanger fitted underneath as standard )but like you say the coolant is hot .. not a oil to fuel exchanger either , but a normal air to oil/fuel cooler fitted underneath in a bit of air flow lots of cars have them . but I was talking about one like the style you fitted in front of rad for oil when towing etc.
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3rd Nov 2013 5:47pm |
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K9F Member Since: 12 Nov 2009 Location: Bournemouth Posts: 9610 |
Better and easier to get the engine to run cooler. Get rid of the catalytic convertor and either the centre box or rear box silencer on your truck, fit a larger intercooler and if budget allows a remap. Guarantee economy will go up and engine running temperature will go down.
From another thread....
If you go through life with your head in the sand....all people will see is an ar5e!! Treat every day as if it is your last....one day you will be right!! |
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3rd Nov 2013 5:53pm |
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munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558 |
Running temprature is controlled by thermostat and cooled by rad ... Rads are made to cope in much higher temprature then we see in the uk so if your rad is in the condition and thermostat is good and as standard ( not sure what a tdci one is ) if it is say 88c it does not matter what you do .running temprature will be the same .. Larger intercooler is not to cool engine it's to make intake air cooler and there for denser also can relieve thermal stress on the cyl head. I think getting fuel down to ambient temprature maybe of benefit . I would say cooler fuel being more dense than hot fuel would give more power per same volume of fuel . Same as cooler air from intercooler more dense more to burn per same volume of fuel .
Fuel on a tdci circulates at a fair rate so fuel in tank gets hot . |
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3rd Nov 2013 6:42pm |
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K9F Member Since: 12 Nov 2009 Location: Bournemouth Posts: 9610 |
I agree with you in principle that the engine will control at the predetermined setting of the thermostat, however If you can get the engine to cool more efficiently and run the engine below the 88 degrees threshold (or whatever the setting may be) it will run more efficiently.
For example today gunning the engine with the airconditioning on and the heater at full hot the water temperature did not rise above 73 degrees, even sat in traffic after the run it didn't go above 78, historically prior to my modifications and taking into ambient conditions you could add another 10-12 degrees to those figures, not to mention the slight increase in economy (even with a heavy right foot) of about another 50 miles per tankfull with the latest map. If you go through life with your head in the sand....all people will see is an ar5e!! Treat every day as if it is your last....one day you will be right!! |
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3rd Nov 2013 9:30pm |
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munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558 |
Why not fit a lower temp thermostat or take thermostat out altogether ... Running temp will be much lower . Driving along it would be best part stone cold sitting still temp might rise a bit but with viscous fan turning all the time moving some air I doubt it would rise much . Also would you work engine hard if was cold after first starting . Why are all race engines warmed up first before start of race . You would rev a cold tight engine
Think what your thinking of is the thermal efficiency of diesel fuel . To get the maximum amount of power from a measured amount of fuel it has to burn at a certain temprature and for diesel that means that roughly 40% is lost as heat that's physics .. Burning fuel below that temprature does not mean less lost as heat .You can't change that . So your engine running temprature has no effect on that .. Running lower engine meaning lower coolant temprature can not change the laws of physics . If temprature is too low thermal efficiency will suffer same as too high it will suffer . Thats why a colder engine will smoke more hense less efficient ..So I would say the normal running temprature should be maintained and the engine should do its best at that temp .. . That's hoping the engine testing department got it right in the first place!!! . Maybe few degrees up or down may help but that could only be worked out on very precise dyno then there is a other things to consider ( fuel quantity ,ambient air temprature etc etc and they change all the time Sitting still on tick over heater on hot and heater fan blowing would enough to keep temp down as heater is on primary circuit and thermostat only controls secondly cooling circuit so yes temp can drop below what thermostat is set at .. But driving is when the heat is made . And I would guess it would make more heat then the thermostat is set at I don't think any change ie bigger intercooler etc we could make will change that. I don't think any remap or bigger intercooler or any other changes could make engine under load produce less heat then that thermostat temprature setting only thing would be if your heater is that good at keeping engine cool as it takes heat out before thermostat so giving lower gauge reading for coolant Last edited by munch90 on 3rd Nov 2013 11:16pm. Edited 1 time in total |
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3rd Nov 2013 10:50pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6294 |
Not sure fitting a better cooler would make a blind bit of difference? Its all to do with compression and expansion and isn't it just the return fuel that gets cooled on its way back to the tank? So as said it would make more of a difference when tank is very low? But even then I would imagine it would be negligible?
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3rd Nov 2013 11:09pm |
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munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558 |
Yes only returned fuel goes back but there a lot of it and it's hot .. It's all a bit of guess work really . Maybe just fill up when half empty not empty so adding cold fuel to hot fuel already in the tank ... Would be nice to know if anyone could maybe see if they notice a difference after long jornery . Maybe I filled up with better grade of fuel on that trip to what was in the tank don't know . But if hot fuel doesn't matter why fit a cooler in the first place as standard .. And would only make a difference on a long jornery any way . Like most things we may find we could improve it .
Google fuel coolers .. They all say denser fuel is better , they even run some with liquid co2 though some to get freezing fuel maybe thats going a bit far for a diesel land rover ! |
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3rd Nov 2013 11:29pm |
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Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6294 |
didn't think about this much before when I commented but having thought about it for a few more seconds is the temp of the fuel / density going to make much difference when its at c1600 bar ?
at atmospheric pressure I would imagine the difference in temp to have a much greater effect but not when its pressurised? |
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12th Nov 2013 7:39am |
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munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558 |
You can't compress a fluid . You can put it under pressure but volume will stay the same . So density will not change under any pressure
If your engine injectors 1 ml of fuel for example ..1ml of cold fuel being bit more dense than hot fuel that 1ml of cold will have more goodness in it to give more power Would it really make that much difference I don't know What I asked first was has anyone noticed they defender go better after filling up on long trip and having low tank of hot fuel then filling with cold . And if does make no difference why do fit a fuel cooler as std . Cooler fuel is supposed to be better lubricant for pump and injectors . IS THAT NOT A GOOD THING So fitting a better cooler to keep fuel cool weather tank is empty or full cant be bad thing as far as I can see |
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12th Nov 2013 7:48pm |
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munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558 |
just found this on diesel site on net:
A diesel engine uses only some of the fuel it pulls from the tank. All of that fuel goes through the high-pressure fuel pump and to the injectors operating under enormous pressure and high temperatures. The surplus fuel the engine is not using goes back to the tank. This fuel is continuously re-circulated and exposed to extreme pressure and heat, which results in the agglomeration of asphaltenes, the high carbon content, heavy end fuel molecules. It leads to the formation of larger and larger clusters and solids, which are very difficult to completely combust. These solids may grow so large that they will not pass through the filter element. They become part of the polymer and sludge build up plugging the filter. In addition, the hot fuel coming back to the tank will raise the fuel temperature in the tank, cause condensation and contribute to microbial contamination, fuel break down, bio fouling and the build up of sludge and acid. Large fuel droplets and high asphaltene concentrations require more time, more energy and higher temperatures to combust than is available in engines during the combustion cycle and before the exhaust valve opens. Any device in the fuel system exposing the fuel to stress (heat and pressure) such as pumps, heaters, or centrifuges will increase the formation of asphaltenes. Fuel systems, in general, are designed to return a significant proportion of the fuel not used for combustion back to the tank. This return fuel is very hot and will promote polymerization and fuel breakdown Short filter life is symptomatic of polymerization, increase in the size of the fuel droplet, agglomeration of asphaltenes and the formation of solids in fuel systems. The consequences are carbon build up in engines and exhaust systems, higher fuel consumption and excessive smoke. |
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2nd Jan 2014 10:47am |
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