Best way to cool down a hot engine

[samcooke]

OK. You've been sitting a while and the water temp is running a bit high, the traffic starts moving nice and quickly and you want to cool it down as quick as possible, so what's best:

1. High gear, low revs so the water pump works less and the water cools more as it passes through the rad - or

2. Low gear high revs so the water goes through quicker and takes more heat away from the block

I'm not telling which one is mine, just in case  

[chazpowerslide]

And how drunk were you when that one kicked off then?

[moomin]

My answer is option 1.5  

Hope this helps,

Moom

[mb893]

Perceived wizdom on a Blackbird is to blip the throttle to jolly the pump along

JC

[Mark Stanton]

Get a very large bucket of ice cold water full of ice cubes and throw it over engine                  

No more hot engine problems, ever again        

[S8ight]

no crumpet to look at in the pub you goto then ?    

[zvezdochka]

I suppose air temp is also an issue, but I go for the 1500rpm solution.  Slight increase in water flow without too much extra heat from increased power.

However, I am thinking of fitting a fan override switch as evry time I'm in traffic and the guage approaches 100C there is that expectant moment of "will the fan cut in or not".  I know engines should run hot but close on 100 always worries me

[neilb]

I know engines should run hot but close on 100 always worries me

Or you could fit a lower temp fan switch - mine comes on at 90.

Neil

[Blacknblue]

I'm not sure it makes much difference either way, if the water is travelling around the block faster it doesn't have as much time to collect heat, so in theory it wouldn't remove the heat any faster, although it would be passing through the block in greater volumes and so would remove more heat. But likewise it would be travelling through the radiator faster and so wouldn't loose as much heat, however as it would be passing through the radiator in greater volumes maybe it would loose just as much heat.

Now if the water was going slower it would collect more heat and would cool the block faster, but because less in volume it wouldn't, again as it would now be passing throught the radiator slower it should in theory give up more heat, but once again as the volume of water is less........        

Real answer - drive faster to the nearest pub and stop for a cool drink   Lemonade of course  

[S8ight]

but if the water moves fast isnt that going to generate friction therefore more heat ?  

[Blacknblue]

but if the water moves fast isnt that going to generate friction therefore more heat ?

Yes, but there's always some more cooler water just around the corner to take the heat away, although in turn that would also generate more friction and then...... we're back to square 1    

[neilwillis]

1.   Fit an electric water pump

2.  Turn the engine off

3.   Put a sock in the missus's mush

4.   Point it radiator towards the prevailing wind

Any help?

     

[7SE]

Sam,

You don't say what engine you've got.  'Cos if you've got a x/flow you would want to get the revs up a bit to restore oil pressure to the outer (and some inner) reaches of the engine.

[samcooke]

We did actually reach agreement after a second night in the pub: Bloke agreed to please desist your current communication on the matter because I'm intolerant of other people's opinions and I agreed not to knock him on to his backside.

[hilux]

if the water is travelling around the block faster it doesn't have as much time to collect heat

True

Equally if the engine revs more then the heat generated is greater  

One of the most forgotten aspects is that your oil is one of the most effective ways of dissipating heat, perhaps an oil cooler is required