To Bow Or Not To Bow?

[AV8]

A question fm thy nebbur: re: Deep water crossing

do you drive through the water at some speed, creating a small bow wave a few cm's in front of the car, therefore creating a trough near the intake or do you drive ever so slowly as not to create a wave at all, thus avoiding splashing the intake?

I've got a snorkel now so don't worry about it.

anyone? Bueller?

[Paul-JK]

I'd say if your mate is that concerned about his intake being vulnerable then he'd need to question why he was going into water that deep in the first place.

In terms of the bow wave though, I'd say that to have is better than not to have. It has other advantages other than just keep water from the air intake. Firstly you're travelling with a little more momentum to help you through any soft patches if the river bed is sandy or to help getting out the other side if the exit isn't flat. Secondly the trough from a decent bow wave will keep the water levels lower back past the doors so it reduces the chance of getting water through the doors seals. It also keeps a pocket of air inside the engine bay keeping everything dry(er) in there as well. If you drive slowly, so as to not create a bow wave, the engine bay will fill up as well.......cough, cough, splutter, splutter, fan blade through radiator, bugger!

[SteveC]

It's simple - through any water is walking pace.

A snorkel protects the engine intake but it's the other parts under the engine that can cause grieve such as the fan hitting the water or spraying water over electrical components which is worse in some vehicle over others

[MRGC]

To add to that spray some water dispersent or lanolin over all electricals in the engine bay, just extra protection.

[AV8]

I'd say if your mate is that concerned about his intake being vulnerable then he'd need to question why he was going into water that deep in the first place.

In terms of the bow wave though, I'd say that to have is better than not to have. It has other advantages other than just keep water from the air intake. Firstly you're travelling with a little more momentum to help you through any soft patches if the river bed is sandy or to help getting out the other side if the exit isn't flat. Secondly the trough from a decent bow wave will keep the water levels lower back past the doors so it reduces the chance of getting water through the doors seals. It also keeps a pocket of air inside the engine bay keeping everything dry(er) in there as well. If you drive slowly, so as to not create a bow wave, the engine bay will fill up as well.......cough, cough, splutter, splutter, fan blade through radiator, bugger!

Thanks Paul. So you would advocate to bow :single_eye: . OK, fair enough and good points on the explanation. I personally didn't ask him if he had crossed deep water, thinking about it or just a general chit chat. I suppose a tarp covering the grill would be in order too.


It's simple - through any water is walking pace.

A snorkel protects the engine intake but it's the other parts under the engine that can cause grieve such as the fan hitting the water or spraying water over electrical components which is worse in some vehicle over others
Thanks Steve. Would that create a bow wave or just walking pace, slow, careful and not create a wave as Paul's explanation above? I never thought about fan damage. I'm now thinking of putting a switch to turn the electrical fan off and/or pull the fan belt off too. I cover some electrical parts/ computer with kitchen rubber gloves, shower caps? I have even heard of people using female protection rubber thingos. What works I guess.:emptiness:


To add to that spray some water dispersent or lanolin over all electricals in the engine bay, just extra protection.
Thanks also MRGC (or JK? :smile-new:) . Yes, I do spray WD40 around every now and then especially before going out wheeling, just in case. I wish these offroad vehicles were more hardy. It seems that we always have to upgrade to go out on trails. "trail rated" = "fire trail". ( Diff breather lines, electrical etc..)

[Steve F]

A small bow wave is a good thing, check the depth first, if it's too deep (depends on the height of the Jeep etc) or a long crossing then run a tarp over the front as well to help keep water out of the engine bay. As already mentioned, a snorkel will protect the engine from water ingress but it wont help keeping electricals dry etc and that's where the bow wave and tarp come in.

I've had water come in my open drivers window on a crossing and that was with a bow wave, it also went in the grill at the base of the windscreen. Luckily on the XJ the alternator is mounted high and mine has standard points (not coil on plugs lik elater models). After the cossing a quick pop opf the bonnet and a check of the airbox (I have a snorkel but just in case) and I was off again with no issues.

Cheers
Steve

[glend]

And don't forget t plug the drain holes in the airbox

[AV8]

Thanks Steve F, Glend.


Bow wave works. (http://m.youtube.com/watch?v=z0hkHUjx1ns&feature=fvwrel)

[TRBN8R]

Most important thing to check before entering water u r not sure about is your insurance.........

[Wooders]

One quick tip for those with manual transmissions - try NOT to change gears whilst in mud or water.
Select an appropriate gear (eg 2nd low) and keep it for the duration.
Changing gears means the water&mud will get between the friction plate & flywheel.

Also if the engine stops with the exhaust under water, consider not restarting but take a strap.
Once the engine stops water will fill the the exhaust system and when you restart there is a risk the backpressure can suck water into the engine.
Obviously this is something to assess on a casebycase basis - but keep it in mind.
There are load more things to keep in mind for deep water crossing, so if possible best avoided, but the MOST important is keep in mind the rate of flow and the effect this has on the side of a 4x4. Misjudging this can and regularly does have fatal consequences.