Stunned Monkey wrote:David Gentleman wrote:Nooooooo, Ive seen you write this on another forum Martin.....
So what you saying is, if I have a nice hot engine bay with the bonnet closed, rev the car hard, and then open the bonnet, it should be nice and cool in there as the engine has just sucked through a huge amount of fresh air to replace it?.....i think not...
How do fan assisted heaters work if the air isnt there long enough....?
I suspect this would be an "agree to disagree" argument. Fan assisted heaters don't shift 230 litres of air every second, and the surface area:volume:heat output of an engine is vastly different from a fan heater, so that's a totaly invalid comparison.
If you open your example engine bay after revving it, you'll be feeling a lot of radiated heat from the engine, which is different from convected heat carried by the air, which I feel pretty damn confident that a constant flow of 230 litre per second over even a hot engine isn't going to make a lot of difference to the intake temp - certainly when compared to the restriction of *some* intake pipework.
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Lol, the whole engine at best might shift 300cfm of air - a couple of 13" engine fans on a rad can shift over 3000 CFM and the air is STILL warmed instantly as it flows through it at that huge speed....and thats with just say moderate water temps...
Change that to air flowing at 10 times lower velocity, over a hot engine block, components over 100 degrees, and exhaust systems from 300-800 degrees......
Don't get blinkered by the impressive figure of 230l/per second, its still CFM, and even 300cfm, means approximately the engine bay area would be 'emptied' of air every 6 seconds, well enough time for it to warm up in the first place, we know you can heat up air instantly just by passing it over an external heat source....but we dont drive around at full throttle/full rpm all the time. In normal driving, midrange and accelleration etc the air is going to be 'in there' for well over 10-15 seconds...but it all matters not as it will be warmed pretty well i about 2!
Maybe to cool our engine bays down, we should put the air filter at the top and the middle of the engine, so its sucks all that nasty hot air in and keeps the engine bay nice and cold..