LS2 - how hot should it run at.

[nike 5]

Wiring my LS2 engine at moment.
How hot does the engine run at, looking at the ECU and it says that.
Fan 1 - comes on at 226 Fahrenheit (107.77celsius) and then off at 217 Fahrenheit (102.77 celsius)
Fan 2 - comes on at 235 Fahrenheit (112.77celsius) and then off at 226 Fahrenheit (107.77 celsius)

This all seems very hot, so I thought I ought to check.
Thanks

[ringram]

Looks about right, you can download efilive software and open some tunes to see what stock is.
Basically its a percentage of fan. Not an on and off. So the hotter things get the more fan speed (and fans come on)

"This table is used to define the percentage of fan power vs engine coolant temperature.
NOTE: EFILive custom operating systems extend this table to allow a wider range of engine operating temperatures to be used for fan control."

Maybe over 60%=fan2 on. Im not sure.

[Magic919]

Primary control of ECT will be the engine thermostat anyway, I presume.

[nike 5]

The thermostat will certainly open long before the fan starts.
The standard thermostat opens at 195F (90.5 C)

During normal running what temperature does a LS2 run at?
At what temperature while driving should you start to get concerned?

Does the LS2 run quite hot to help emmissions.
As had been led to believe that to increase power you needed a relatively cool engine (basing this on knowledge gained from older style engines so a modern engine is a bit of a culture shock at moment).

[ringram]

nike 5 said:

As had been led to believe that to increase power you needed a relatively cool engine (basing this on knowledge gained from older style engines so a modern engine is a bit of a culture shock at moment).

Thats a good topic to debate, a lot of info on the matter and nothing conclusive is my findings..

Colder = tighter and not as good vapourisation of fuel etc, you can ramp spark up too.

Warmer is hotter intake temps.. But a cold air intake can help this.

I kind of drop temps a bit but not too much.. Some shops use 160*F thermostats in high power engines.. Id like to find something definitive.

[Magic919]

I expect about 190-200 F for normal running. But I'll stick my dash in diagnostic mode tomorrow and see what the commute to work brings.

The LS2 can sure belt out heat but I don't feel it runs unduly hot. I'm sure you can find info on this as the LS2 is not such a rare lump (more outside UK, of course).

Keeping ECT and oil temps down is good, but you also want to stop the thing seeing high Intake Temps. If the standard ECM (presuming you are keeping this) sees those it starts yanking ignition timing and that will reduce power output.

[stevieturbo]

Ive seen very few, if any people in the US reccommending the cold 71degC stats. Most stick with keeping the engine fairly warm.

Ive tried the colder stat for a while too....mostly as my cooling system isnt as good as it needs to be.
You end up with condensation in the crankcase and breathers, which is undesirable.

So I'm back to running an 86degC stat, which is a happy enough medium IMO.

If we ever get some very warm weather again, I'll refit the colder stat when racing, but thats about it. I wouldnt consider it for road use.

[nike 5]

MAGIC919
Sorry for my ignorance.
ECT = Engine Coolant Temperature
But what does ECM stand for.

Based on the temp of the standard thermostat I would guess the running temp will be hotter that 190-200 otherwise there is no flow through radiator. However this originally was the temp range that I had been expecting. So I will be very interested in your results tomorrow.

Ringram, I will be using a small radiator (car not a Monaro). I am concerned about 'potential' overheating issues, (I have not got car on road yet), and have purchased a 160F (71.1C) thermostat from Katech
(part number 100228 - http://www.katechengines.com/street_performance/en...
with the intention of installing it at a later date, and starting fans spining at a lower temperature, if temperature becames a problem.

Warning from Katech
"it is recommended that your computer be re-calibrated for the cooler operating temperature"
Do they mean ECU to control fan(s)or is it more involved that this (as this could easily be done by traditional thermostic switches to control fans).

They also say
"This is recommended for Racing and Street Rod applications only as the engine would not get up to temperature in a stock application." with the size of my radiator that will not be an issue for me.

Stevieturbo
will take on board your concerns over condensation

[rmmackfc]

nike 5 said:

But what does ECM stand for.

Engine Control Module? ie ECU

[ringram]

Yeah retune for fan control, but also to check for fueling and timing changes. If the basetune is good then it should already have the tables for lower intake temps etc. But the colder engine may affect things like friction etc so it would be best to check/tweak the tune to suit. Thats my guess anyway.

[Magic919]

Ok. This morning was about 17C ambient. Car moves up to about 188F fairly quickly. Then takes a while to push up to a new level of 200+. With a bit of traffic it can get as high as 218F. The fan must step up there as it pushes back towards 200F.

This is from the diagnostic mode on the dash and I presume it is data sourced from the ECM.

[Magic919]

Took the motorway for a few miles on the journey home. 190-195 and even saw 188F just before the slip road off.

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Magic919 said:

Ok. This morning was about 17C ambient. Car moves up to about 188F fairly quickly.

Chances are that the cooling system is running closed loop with the thermostat closed so the water stays in the engine to help reach operating temp as soon as possible

[quote]
Then takes a while to push up to a new level of 200+.
[/quote]
That'll be the stat starting to open and letting the coolant run through the engine.

[quote]
With a bit of traffic it can get as high as 218F. The fan must step up there as it pushes back towards 200F.
[/quote]
104c is about what I'd expect for the fan to go to full and bring it down. IIRC the fan should go to full and stay at full until the temp is back down before resuming normal operation where it speeds up as required.

[quote]
Took the motorway for a few miles on the journey home. 190-195 and even saw 188F just before the slip road off.
[/quote]
I'd expect it to be fractionally lower. the sheer amount of airflow means most thermostats are running almost closed. If you changed down and increased RPM then this can cause a 'blip' in the coolant presure forcing some through before the stat can compensate.

To be honest, small variations will happen and sometimes a digital temp reading can be a curse as the slightest change makes you think "is that normal"?

[Magic919]

I think I'm fairly happy with how my car is operating. I was just giving the OP the data he was after.

According to the ECM my fans rise to 50% at 105C and don't get near max until 113C, if you are interested. It runs at 25% from 89C by the looks of it. The ECM has the ability to turn off the fan above a selected speed, but I'm not clear exactly the parameters for this.

Edited by Magic919 on Thursday 17th July 21:51