Wading Blankets - worth the agg?

[SteveS]

So I've never used a wading blanket to wade with (used it to keep the Deafener warm in Arctic winter) but it got me thinking as to whether using a wading blanket when fording was just a lot of BS or whether it really is the mutts?

Often stated reasons:

It'll keep the engine bay empty of water and dry - don't believe that. What happens if you have to stop/slow....how does it magically seal all those massive holes?
It'll help keep the radiators away from all that nasty floating detritus - partial, my 100 has a massive space under the bar where the water will go. I have some fine garden netting mounted behind my grille to catch bugs, stones and general floating stuff
It'll help with the bow wave - it will i guess add some more push, but you'll need more power and grip to push that water. And in any case i have a properly installed snorkel. The bow wave disappears if you have to stop/slow.
Water hitting the fan causing it to spray everywhere and break fins......does the fluid driven type suffer from this too? Fan is often cowled.

I've got an old tarp and some bungees so it is no biggie to fit it over the grille......but i can't see the slam-dunk reason why i should bother

Thoughts anyone? Perhaps I'm missing something

 

[Chris]

Never used one I and I have been up to my what-sits on many occasions. BUT. What it does do is stop mud lodging in your radiator. Mud in the fins, goes hard, reduces cooling, impossible to clean without removing the rad ... So it's not wading that's the issue, it's the filth in the water. If of course it's dirty water. Clean river crossings are quite different.

 

[Blown80]

Steve, all those notes are valid. The other issue to keep in mind is as that volume of water engages with the fan it can be pulled into the back of the radiator causing damage to the radiator itself. We do often see the results of this in vehicles we service.
Plus the more you can prevent getting all that muddy water through the alternator and brushes the better, plus as Chris mentioned. I've done many a crossing without, but take the time to prepare properly for deep crossings. It's worth the effort. Cheers

 

[SteveS]

Thanks both - I will take a look at the fan to rad spacing so I can understand the dynamics of that. I think with the alternator being at the low side of the engine then I will just have to live with that risk. With respect to my impending Iceland visit most of the rivers there have a lot of glacier melt water which is laden with fine pumice/moraine particles rather than mud but the point still stands. River crossings never to be taken lightly

 

[SteveS]

So on my 100 the fan has a good 6cm between fan blade edge and radiator and also would be downstream of water that would have been forced through the radiators from forward motion - so I don't think that that would be a problem. The alternator is higher up than I was imagining so anything deeper than 750mm is going to get in there. A blanket won't help much as the water will be flowing up under the front bar and plates. Which leaves the silt problem in the radiator........the bottom 1/3 of the rad would not get any benefit from a blanket - unless I take the blanket right round the bars and fix to under engine plate - the top 2/3 will however get some benefit. I will plan on back flushing the rad between trips. I did this on my 110 - soooo much mud came out

 

[clivehorridge]

It's not the flow of water through the rad fins that causes the fan to catch on the rad, it's the fan trying to "propeller" the water that pulls (or pushes) the plastic fan blades forwards towards the rad. That will happen even if you're stationary, if the fan is being driven and it's under the water.

In the old days, we had steel fans which didn't deform under any circumstances, they just played merry-hell if they broke

 

[SteveS]

Ok I understand that the fan will try to turn and screw itself towards the rad.....but that's a pretty big gap, pretty stiff fins (and/or breakable with that amount of deflection) and would the viscous coupling help effectively stalling the fan?

Anyone have experience on a 100 doing any of this?

 

[Shayne]

I don't know anything about wading blankets but as i understand it the viscous should disengage or at least slip when you crawl into water same as it will on an icy morning to prevent power loss when cooling is not required .

 

[Dave_S]

Steve - in case you missed it... wash everything after Iceland. The silt and volcanic ash get everywhere - within a year I had problems with door locks, master and slave cylinders, etc - I don't regret the trip for one moment, but I do wish I'd spent a good weekend cleaning and greasing afterwards...

 

[Ben]

Having driven hundreds of river crossings myself and having watched people with me on the same trips also drive them, only once have I ever seen a fan blade go through a rad and in that particular case it was a fast flowing river and he drove in flat out to make a big splash for the cameras.

I have heard of people turning the engine off before the crossing and using a ratchet strap/bungy strap/rope etc. to secure the viscous fan so that it cant turn. Then after the crossing removing what ever secured the fan and carrying on. This also has the added bonus of it preventing the fan from kicking water up all over the engine. Not that a bit of water will hurt a diesel but certainly good if you drive a petrol.

IMHO so long as you drive in nice and steady I dont think the viscous fan through the rad is worth worrying about.

 

[uHu]

With the engine hot, the viscous coupling would be driving the fan hard. If you enter the water at idle speed, and give the viscous coupling time to react to water temp, you'll be ok.

 

[SteveS]

Steve - in case you missed it... wash everything after Iceland. The silt and volcanic ash get everywhere - within a year I had problems with door locks, master and slave cylinders, etc - I don't regret the trip for one moment, but I do wish I'd spent a good weekend cleaning and greasing afterwards...

Thanks Dave_S - good advice - I'll try and find a jet-wash in Denmark or Germany so that I can get the worst off.....seems that this is an attention to detail to flush out all the rotating/moving bits...often the damage is done with the grit already embedded somewhere. Good advice all the same.

 

[SteveS]

With the engine hot, the viscous coupling would be driving the fan hard. If you enter the water at idle speed, and give the viscous coupling time to react to water temp, you'll be ok.

UhU/Ben - I tend to be mechanically sympathetic - particularly with a fully loaded truck - so a steady entry into water would be my usual style. Not always possible of course, but entering water like a log flume takes with it the risk of damaging something anyway. Looks good on the photos though! Good to hear that it is a relatively rare event to damage the rad.

I might put my waterproof video camera inside the engine bay when i do a crossing - would be interesting to see what happens.......assuming the camera picks up the action with all that spray

 

[Gary820]

I've seen people break viscous fan blades driving through water but they were going too fast. Damage to rads and hoses usually happened. I've driven the same ford after/before them in the same make of vehicle with a more open front tubular bumper and never broken a fan or damaged a rad. Had water over the bonnet many times too.

You have mechanical sympathy, you'll be fine.

 

[frank rabbets]

Mud can also get into the air con pump pulley sleeve and bind it to the body so it does not turn, burning the belt out. The sleeve is designed to keep mud away from the sealed bearing but in doing so can seize itself.