F1 Radiator Fans

mx_tifoso · Post 11 Jul 2007, 18:43

I have a simple question regarding the cooling of radiators with temporary mounted fans, more specifically when the engine is turned off. For example the photo underneath, the engine is not on but the car still has radiator fans on it. Do the fans still have a cooling effect on the engine through the radiator even though the entire powertrain is not operating?

You can tell the engine is not on because the mechanics are pushing the car to the starting position (or is it being pushed "on" in neutral

). If the fans do not serve their function while the car is turned off, then why are they on, or needed?

The engine is not on for a considerable amount of time between the roll from the pits to the start positions, so I dont believe the engine is in dire need of cooling. And only until right before the formation laps are the engines turned on (IIRC), with no more techs/mechanics on the grid anymore.

I know it is not a complicated question, but I still dont have a definate answer from what I know about this technical aspect.

Feedback would be appreciated.
Thank you in advance.

manchild · Post 11 Jul 2007, 23:06

They are in place but not working. Besides, even if they were working on car with engine turned off it would help cool the engine down because as much as I know F1 engines don't have thermostats so if cooled in radiators water would flow like in thermosiphon cooling systems.

wowf1 · Post 11 Jul 2007, 23:34

Yes plus the coolant in engines is most likely to boil after the car has come to rest. This is because either the fans have turned off (in more primitive road cars) or in the case of an F1 car, no air passing through the cooling system and so all the heat contained within the engine block soaks into the coolant. This causes the coolant temperature and pressure to rise, and potentially boil despite the engine being off!

Whilst the car is in motion the cooling is generally satisfactory. And above 100mph cooling is more than adequate (despite higher load on the engine). I believe the engines struggle mos during slower periods such as under safety car conditions, during a pit stop, and especially sitting at the end of the pit lane a la Hamilton! While I mention that, I was at the British GP and heard over the tannoy an interview with one of the team's engine personnel. The interviewer asked how this year's engines were able to sit at the end of the pit lane for so long, and the reply was that apparently some teams run their engines only on 2 cylinders for those 3 minutes or so! I guess there's an extra mode on the steering wheel or something. Anyway thought I'd share that tidbit lol.

ginsu · Post 12 Jul 2007, 00:09

The interviewer asked how this year's engines were able to sit at the end of the pit lane for so long, and the reply was that apparently some teams run their engines only on 2 cylinders for those 3 minutes or so! I guess there's an extra mode on the steering wheel or something. Anyway thought I'd share that tidbit lol.

Wow, I wish my road car did that at stop lights. I didn't know that they shut down any cylinders in F1 cars. That is actually road-relevant technology! I wonder which two cylinders are running though. I'm thinking the 1 and 8 at opposite ends of the crankshaft and obviously on opposing banks.

Cyco · Post 12 Jul 2007, 00:46

I wouldn't be a consistent 1 and 8, like when the traction control is in operation they would cycle through what cylinders are being used at the time

DaveKillens · Post 12 Jul 2007, 01:54

The Cadillac Northstar engine had a fail-safe mode if there was a loss of cooling. The engine would alternate using cylinders, so each cylinder would have the two strokes for power, then the next two strokes just pumping air. The air would pump through the head and cylinder, adding a small but significant cooling effect.
If you applied that to a GP engine using just two cylinders for power, (and they alternated) then each cylinder would have two strokes for power, and six pumping cooling air. As well, they would run as rich a mixture as possible for additional cooling effects.

Ray · Post 12 Jul 2007, 04:09

Actually Dave, ALL of the Generation 3 GM and newer (LS1,LS6,LS7,LS2, and so on) engines use a fail safe mode. I have a derivative of that family in my truck. They alternate every other power cycle and richen the mixture up tremendously. You can drive a considerable distance like this, you won't have any power to speak of and it is absolutely required you change the oil as soon as possible. The fuel washes the oil off the cylinder walls and contaminates the oil in the pan.

manchild · Post 12 Jul 2007, 17:53

Alfa Romeo experimented with that almost 30 years ago on their 4 cyl engine for passenger cars for fuel saving purpose.

mx_tifoso · Post 16 Jul 2007, 19:29

Ray wrote:ALL of the Generation 3 GM and newer (LS1,LS6,LS7,LS2, and so on) engines use a fail safe mode. I have a derivative of that family in my truck.

Are you talking about a Silverado or Sierra ('99-'07)?
-------------------------
Thank you guys.

Good responses from all of you.
Even if it wasn't a complicated subject, it always helps to understand more about this kind of stuff.

- mx_tifosi

Belatti · Post 19 Jul 2007, 15:24

Remember thermal inertia, the heat inside engine is still there and the water pump is off, so coolant temp goes to the clouds.

I experimented that in my road car, when the temp was 88C and I stopped it, then 2 minutes later the temp was 92C and the fan started!