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jtd diesel cooler?

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cooler diesel
3K views 15 replies 5 participants last post by  spike60 
#1 ·
im sure a few have fitted them any details(pics if any) what was fitted and where and worth doing? or not much benefit noticed?
i know if i pull up pop bonnet and feel fuel rail its hot to the touch, any benefit from lagging rail with exhaust wrap etc
i understand cooling diesel before return to tank to save plastic lines and tanks, but any point cooling fuel supply to pump if rail is already hot from engine temps+higher rail presures.
 
#2 ·
Colder-denser is always better, but effectivity of cooling diesel fuel BEFORE high pressure pump is IMHO negligible.

If the fuel is getting hotter than engine compartment temperature, it may be useful to have cooling fins on pipe after CR pump and rail as well. But with the high fuel flow and short travel distance I'm not convinced about the effectivity either.

some topics for hardcore players - peltier cell or dry ice cooling
 
#3 ·
#4 ·
I think the diesel radiator is useful if you drive hard for a long time. Diesel that returns is hot and if you don't cool it it will keep more heat and when it goes into the pump again, it will heat more and more. I've heard of temperatures in fuel going upto 80ºC on track driving. Cooling this would be useful.
 
#5 ·
just logged a few power runs wot but short runs, after logged fuel temp(at filter)
max temp at end was still only 26*c and thats about ambient at the moment.
no idea what actual rail temp is but its a lot higher than 26*c, might just try some reflective wrap around rail.
 
#6 · (Edited)
tried a thermometer on rail after normal casual driving and it shot off scale(only 42*c)id say its 60*c+ by hand feel, whats interesting is now feeling the incoming fuel pipe from pump to rail is quite cool by comparison(20-30*c)
certainly looks like the fuel rail and outgoing pipes are absorbing the ambient heat from the engine temp.
have bought some heat reflective tape to lag it (keeping away from nuts and fittings though)
looking at the 2x locating bolts and tabs, theres quite a surface area to transmit conductive heat into the rail, do you think its possible to isolate with washer of teflon or laminated phenolic or similar?(thats if i could get one in without upsetting the spacing of the rail and pipes?)
heres a pic of what and where i mean.
View attachment 144819
 
#7 ·
Interesting. Try to isolate the rail and log fuel temp again.
 
#8 ·
Fes logging is no good as its in filter, got a infra red thermometer on the way and some tufnol sheet in 0.5mm/1mm/2mm so will lag for now and try insulating when stuff arrives.
When thermometer arrives I'll use feed nuts on injectors and nut on pump exit and fitting for rail sensor as test points for logging.
 
#9 ·
I know the fuel temperature is measured at the filter, but didn't know you can measure it some other way. Btw the temperature change would be noticeable there as well.
 
#11 ·
Any noticeable change on fuel temprature sensed by ECU?
 
#15 ·
O.k laser thermometer arrived and checked on a boiling pan of water 98-99c.figures with warm car idling I was getting before and after 1mm tufnol spacer.
Outlet filter=21 after=21
Outlet pump=23 after =23
Inlet rail=38. After=30
Outlet rail=43. After=38
Rocker box=50. After=50
Rail bracket=48. After=36
Injector=50. After=50

It is what it is, cooler yes worth while ?probably not.
1mm tufnol was a squeeze, wouldn't try thicker. And bolts were well tight.
May suffer in winter?it starts off cold anyway.
 
#16 ·
As the injectors will be pretty much at the cylinder head temp won't cooling the fuel before it arrives be lost when it gets to the hot injectors?
I use temp guns at work and the laser is usually only to aim it, I assume they work on infra red or similar principals. They also don't work well on all surfaces, a transmission with shiny alloy cases can read 35c when in reality it is about 80c, -as your skin will tell you!
 
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