velohead66

1998 Classic

Just wondering, say on a very hot trackday, where ambiant air temp is hot, and the car is driven fast,...
1) what temp the water would reach
2) where the temp is measured
3) what would be normal temp (or temp range)
4) if water is considered too hot by the ECU, what would happen then.

Thx.

saiklon

1. The rad fans get turned on at 95 deg C. If your cooling system is fine (no air in system, rad not blocked), that is the maximum temperature the coolant will get to (however oil temperature can still continue rising so some people fit oil coolers).
2. The temperature is measured at the metallic pipe crossing over from the left to the right side of the engine block.
3. Fans go off at 88C and turn on at 95C so that is the range.
4. The ECU does not do anything if the coolant overheats.

velohead66

On a 30ºC trackday, the coolant reached 99.9ºC but on a later session (same day) it reached 101ºC. The engine didn't seem quite right, so I came off track.

Should I be worried about it reaching 101ºC ?

Not sure if it is caused by...
a) heat soak from turbo
b) poor cooling through FMIC then radiator.

Plan to fix these by...
a) turbo blanket
b) better air flow

Should I be worried about it reaching 101ºC ?

alcazar

iTrader: (2)

I cooked my classic on a French motorway when ambient temperatures were 40+ and I'd been driving "spiritedly". Came up to a toll, slowed, passed through, blasted away and every warning I had lit up like a Christmas tree.

saiklon

Yes, you should be worried about it reaching 101C, it means that your cooling system is not up to the task.

The one time I had overheating issues (excepting leakages and thermostat failures) was when my AC rad and radiator fins were clogged up. I think you should concentrate on the radiator airflow. I'm not sure how much your FMIC is blocking the radiator but with straight and unblocked fins that should not be an issue.

velohead66

Then what happened ?
Any damage to the engine ?

velohead66

I took the air conditioning condensor out, which sat between the FMIC and the Radiator.
I thought this would improve air flow, but obviously not enough.
I'll look at airflow to the radiator.

I do have data aquisition, and can get oil pressure, but not oil temp.
Should I be monitoring the oil temp too ? It may be possible to do that for a few $.
I guess if it's too high (oil temp) i could get an oil cooler.

Just wondering, in my voyage of discovery.....
what would be safe max/min oil pressure for classic MY98 ?
what would be safe max/min oil temp for classic MY98 ?

Ginola

iTrader: (25)

mine sits at a constant 85 when driving arround even driving hard , but rises up when stationary fans kick in at 91 , but this is on a power fc not a factory ecu.
I have never seen it reach higher than 92 in mid summer driving hard for 20miles and pulling up.

I dont have a front mount mind.

Martin 2010

iTrader: (9)

get a lower temp thermostat for hotter weather will allow cooling running temps, this is what im going to get for mine next ( once box is done ) ready for the summer,

saiklon

In my opinion oil pressure is enough since if oil temp gets too high, the oil pressure will drop a lot (at least at idle).
Min oil pressure is usually 2-3bar at idle, max oil pressure should be of no concern since there is an oil pump relief valve to take care of that.

Not sure about what safe oil temps should be.

velohead66

sounds like a good idea.


Just wondering, if the water temp is 101ºC, and the water is circulating, and therefore presumably taking heat out of engine, if there is still danger of engine damage ?
And if so, in what way ?

saiklon

As engine temperature goes up the engine is more prone to knock, what Alcazar referred to above in post 4 is knock due to heat soak.
Technical paper here about this issue: http://www.iiis.org/CDs2010/CD2010IM...df/FB075TI.pdf
The oil will also become thinner so offering less protection

Tidgy

whats your oil temp doing?

velohead66

Can't measure oil temp, at this point in time.

I can measure oil pressure, though.
In psi.....
between 70-80psi at start of track session
falls to 50-60psi near end of session (with negative spikes of say 30psi)
then approx 16 psi on tick over (cool down with zero speed)

I guess the negative spikes (is there a better word for neg spikes ?) occur as a corner is started ?

velohead66

Here's the pic of the above oil pressure...

http://i1011.photobucket.com/albums/...QR120211s1.jpg

velohead66

wow, I think I'll need a little time to digest the technical paper.
Regarding knock, I'm using 98 RON, plus octane booster.
Also, the FMIC should reduce air intake temp, IIRC to approx 48ºC


Maybe I also need to use different viscosity oil, and/or oil cooler.
As well as improved air flow through radiator, of course.

saiklon

16psi of oil pressure at idle is very low.

There is a rule of thumb that there should be 1 bar of oil pressure for every 1000rpm. However the general opinion on Scoobynet (from posts I've read) is that 2bar is about the acceptable minimum to have at idle.

If your oil pressure is 2bar+ at idle when warm on a normal day without track driving, then you are in need of an oil cooler. If the warm idle oil pressure is always 16psi then you need to have a look at your oil pump and engine bearing clearances.

Maybe you also need to compare your oil pressure gauge reading to another gauge, it might be inaccurate.

Tidgy

was just looking at that myself and the oil presure does seem very low indeed. Persponaly i'd get an oil temp gauge on there before you do anything else, i think you'll find the oil temp is sky high.

velohead66

thanks for all your info, I've learnt a lot from all your posts.

I might have to do a trail run, ie just take it out on the public road, do normal driving and see how all the pressures/temps vary.

Mmm, seems I have a very hot engine, not good.

Tidgy

you'll prob find track work the oil goes even higher than roads.

your not the only one with a hot engine, mine saw oil temps of 105 on the road before i backed off, got an oil cooler fitted and 4 years later its still going strong

velohead66

so was the oil temp gauge hard to fit ?

My garage/tuner seems a bit reluctant about fitting an oil temp sensor.

Tidgy

not rocket science as i understand, from what i remember mines comes off from the same location as the standard sensor.