heat extraction

[keith-vznby]

Hi , as a chim novice I have been reading the forum for info.I read a lot of threads on heat which caused me to think as follows. When I was driving sevens there was always heat issues, I found that the best cure was two small 6 inch fans extracting at the same time as normal rad fans, we put then the sides of the engine bay but I have seen then mounted in inner wings exhausting into wheel arch.Does anyone know if this is effective in this case, cheers keith

[ClassiChimi]

It's true the under bonet temps do get high but as long as the two rad fans kick in the engine will run at normal temps,,,
The easiest way to remove a lot of heat is to remove pre cats in exhaust manifolds, that will drop temps to a usable level without the need for extra fans

[bobfather]

ClassiChimi is right, precat removal makes a significant difference to under bonnet temperature. It is not an issue for MOT either because emissions are measured with the engine hot and the main cat is more than capable of cleaning the emissions. It also sounds nicer and breaths better. It's a no brainer

[QBee]

Switchable extractor fans sound like a good idea -
both electrically, so that you can cool the engine bay when you need to, for example on a summer track day,
and directionally, so that they vent to the road on hot days, but into the footwells in winter.

I am not alone in having a car that, on a hot summer track day can have the fans running non-stop when I am on it on track,
but, on a motorway journey in winter, requires the occupants to wear thermals even with the heater on full blast.

I am feeing that a ChimpOnGas essay/novelette at this point would correct the error of my ways and my so-called cooling system, two birds with one stone

[Sardonicus]

You got big problems QBee if your fans are running when flying round a circuit even if you have the low temp fan switch fitted I suggest you get your rad looked at if thats the case

[ClassiChimi]

^^^^^yeah that's what I've been thinking,,mmm? Your not known for taking it easy around the odd race circuit Anthony so the air going through should be keeping it in check,,, I'm using an alley rad yet mine still gets toasty on a cold morning?
Even at 5000 revs the engine should be staying cool enough even on track? Maybe the stat isn't opening fully or something daft!

[QBee]

Sardonicus said:

You got big problems QBee if your fans are running when flying round a circuit even if you have the low temp fan switch fitted I suggest you get your rad looked at if thats the case

Well, we should know if it was just a clogged rad, as I have had the rad re-cored since the last track day this year - it got hit by a stone and holed.
So new core fitted, and the rad was re-installed by Maestro Mat Smith, so there should be no question of air locks.

In its defence, I have to say that I do keep the revs high the entire lap on a track day, so the poor thing only gets a rest when i stop for a break.

Only observation since re-core is that the car was pretty cold (as usual) on the way to London last month, so maybe I need to have the heater matrix flushed? It only warmed up when Alex hopped into the car en route, and added a small amount of body heat but plenty of hot air.