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Screwloose - I love your summary, the best bit being how to decide enough is enough. I will certainly remember the wheel centre tip.
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"managed about 4 or 5 foot in a hire car the other day, just went for it"
We went through 9 feet once by going for it in reverse and relying on cavitation to keep the air intake clear and personal gas to keep the cabin pressurized.
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"personal gas to keep the cabin pressurized"
You must have been on the Marstons Pedigree - it has that effect on me too!
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One of my cars has got the 'cat' under the car. The cost of a new 'cat' will buy an awful lot of petrol to find a suitable detour.
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If drawing in water through the Air intake is the main danger, there may be a few boy-racers with regretting fitting those ground level cold air intakes !
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4 inches?
wow u not seen nothin have you
out in south west was it last week or the week before i forget i drove through very deep water, which was very unexpected, just flash flood i guess on top of already overflowing rivers etc, there would have been nowhere to turn round anyway, thin country road, and as soon as you go for it theres another car 10 foot behind doing the same, it was a A road as well (yes you do get thin A roads in the countryside) and I knew the people behind would get trapped so I called the fire brigade as soon as I found somewhere to park, the next day the police were blocking the road as it was circa 10 foot deep and nobody would have go through if they had started off down the road
last weekend slightly less deep water somewhere else I had a chance to turn round so turned round, surprising number of grannies going for it though
isnt it the focus that has a very low air intake for the cabin air? wouldnt like to be in one of those
none of this is the deepest ive been through though, was in a flash flood in the north east with my mother in the passenger seat, totally unexpected, overwhelmed the drains and boy was it like driving a submarine, just made it home which was on high ground thankfully :) them old cavaliers sure were good cars!
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At five foot surely the water level would have been higher than your head when seated in the car. Remarkable story and one I must remember.
wemyss
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At five foot surely the water level would have been higher than your head
Seeing as most cars will start to float at around 18-20" must've had screw propulsion and rudders like an Amphicar.
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>> At five foot surely the water level would have been higher than your head Seeing as most cars will start to float at around 18-20" must've had screw propulsion and rudders like an Amphicar.
A conning tower, and torpedo tubes more like ..
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As I mentioned on a recent thread, a few days ago I was crawling through flood water, maybe 4" deep, in a Ford Ka. An idiot in a Land Rover on the other side of the road decided to take the flood at high speed, creating a large bow wave, and huge 2m high waves either side, which completely engulfed my car.
We have a local road in Luton which goes under a railway bridge, and it often floods so as to be impassable. I've seen a car or two stranded before.
I have to admit that it is only because of this site that I know how to drive through a flood (slowly with high revs) and to avoid anything but shallow ones.
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>>with high revs
What's the logic for high revs?
Number_Cruncher
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well you need to keep the revs high to keep the exaust pressure high, so you need to be in a lower gear than normal, and foot holding the revs up if changing gear
all to stop the water versus gas battle that will be taking place at the pipe opening
drive like normal and youre at much higher risk of stalling from water blocking pipe
also phycological affect mainly now, but on a car which could misfire or whatever having some momentum in the flywheel to keep the engine running would also reduce risk of stalling, less important in a modern well maintained car
sure there are other reasons?
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>>water blocking pipe
I can't believe this bit. Engines will continue running (albeit not producing their full power output) with almost completely blocked exhausts, and the water pressure we are considering can't be great - 4" depth of water is equivalent to about 1% of atmospheric pressure.
Perhaps there should be a motor car edition of QI, where these long standing myths can be well and truly debunked. Ackerman steering geometry is another long standing bit of nonsense that I would like to see expunged from text books!
The flywheel angular momentum argument I do like though - being in a low gear does give your car more kinetic energy without giving it extra forward speed.
Number_Cruncher
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retgwte
There is no battle; a modern engine is a very efficient air pump indeed and can easily produce 40 or 50 lbf/sq/in without even firing; [try holding your hand over the tailpipe and crank it....] There's no need to have the engine at anything but idle - you should only be doing about a quarter of an mile-per-hour so there will be no changing of gears needed.
As you're only going to be in a safe depth of water, there's no reason why you can't switch it off - if some idiot is coming the other way with a bow-wave the size of the Titanic it's a good move. Wait until it's a millpond again, start it up and resume your quiet progress. No stress - no rush.
Even if the complete exhaust were full, it wouldn't take many seconds for it to be expelled. Trust me; I've done enough breakdowns up to my knees in floodwater to know it works. A few squirts of WD40 and they usually started - in those days the air intakes were right on top of the carbs.
Edited by Screwloose on 23/01/2008 at 23:25
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dunno cold water inside the catalyst may make it crumble thesedays?
i dont pretend to have done any great experiments, but having watched cars driving through water for 40 odd years the ones that have got stuck have generally been the ones low on revs, and the higher reving ones more often made it, sort of becomes instinct from personal experience if you know what i mean
anyways we should run a test, anyone got a hire car at the moment?
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As you're only going to be in a safe depth of water, there's no reason why you can't switch it off - if some idiot is coming the other way with a bow-wave the size of the Titanic it's a good move. Wait until it's a millpond again, start it up and resume your quiet progress. No stress - no rush.
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This hasn't been my experience. Last time I stalled a car in a ford (15 years ago), it wouldn't restart until it was pushed out, at which point it restarted at once. This was an old Nissan Bluebird.
Water over the exhaust certainly does stop some cars from starting.
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.. through flood water, maybe 4" deep, in a Ford Ka. An idiot in a Land Rover on the other side of the road decided to take the flood at high speed, creating a large bow wave, and huge 2m high waves either side, which completely engulfed my car.
4 inches? How can a large bow be created by 4 inhes of water? This in turn creates 'waves' of over 6 feet in height? Yeah, right... You got a bit splashed in in other words. Hyperbole at its finest!
Edited by woodbines on 24/01/2008 at 00:14
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4 inches? How can a large bow be created by 4 inhes of water? This in turn creates 'waves' of over 6 feet in height? Yeah right... You got a bit splashed in in other words. Hyperbole at its finest!
Not a word of hyperbole. I simply described what happened, and I was genuinely expecting to be stuck. Watch a car go through a flood at speed, and you will see water thrown up, especially from a large vehicle such as a Land Rover. (Well, large compared to my motorised tea pot.)
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