The alternative to a snorkel

[Roger Fairclough]

For 99.99% of your yearly mileage, you don't need a snorkel but for that 0.001%, if you have not got one, you could cause catastrophic damage to your motor.

With this in mind and as I don't like snorkels, per se, I started looking for an alternative. My reasons for not liking the snorkel are noise created, visual problems created by its mere presence on the windscreen surround, and its susceptibility to damage: one was destroyed at Lincomb.

My answer to the problem was an air valve, operated as required by the driver, that would under normal circumstances draw air from exactly the same place as the original air filter but could,on demand, draw air from within the passenger compartment.

This shows the unit fresh back from the platers.

The flap valve.

The unit partially assembled with the flap valve coated each side with foam plastic.

This is the entry point in to the air filter box.

The complete unit, painted and complete with operating arm and return spring.

This is the 75 mm i/d pipework that goes from the engine bay into the passenger compartment.

The unit fitted in place complete with hose work. The unit fits in place of the windscreen washer bottle which I had previously junked. I converted the headlamp washer to replace it.

Roger

 

[adrianr]

Very clever and neat install!!

 

[Ben]

really nice work Roger.

just need a pic now of you fording a river with the water half way up the windscreen, with no snorkel!

 

[Roger Fairclough]

I'm not that brave Ben Anyway, from experience, if a river was that deep, I'd need propellers or a decent Admiralty pattern anchor.

I haven't fitted a method of actuation from the drivers seat yet. I am thinking of either a mechanical system using piano wire and bowden cable or an electro magnet. I like the idea of the latter, it's just a matter of figuring a way to do it.

As a matter of interest, the entry pipe into the air filter, that's the original one, has a flow area of 2333 sq.mm. The new 75 mm i/d pipe has an area of 4418 sq.mm.

Roger

 

[jeepmadmike]

I never see the point of driving in silly deep water so it looks like a good solution for the shallows lol

I love the way most modern stuff has a wading depth of less than a pair of trainers, what do manufactures expect people to do?

 

[John_McCartney]

Really good design, Roger. Hmm. May have to nick that idea . . .

 

[Ben]

I never see the point of driving in silly deep water so it looks like a good solution for the shallows lol

I love the way most modern stuff has a wading depth of less than a pair of trainers, what do manufactures expect people to do?

because its fun and gets the adrenalin pumping.

i know not every one thinks the same though. on my laning trip when i drove strata in full spate, there was 3 other trucks who decided to turn back.

 

[Birder]

cool idea Roger, and your normal great engineering

 

[SpinDrift]

Looks like a good idea. It could also have potential in dusty environments.

 

[Roger Fairclough]

Looks like a good idea. It could also have potential in dusty environments.

Yes, that's another reason I don't like the standard snorkel idea. Another reason was the time I drove down the M1, just south of Newcastle upon Tyne. There was a cloud burst that lasted for about 30 odd miles and the spray was higher than the big artics. Anyone with a forward facing snorkel head would have had a problem.

Roger

 

[Chas]

Clever idea Roger, regarding rain storms, would the small amount of rain entering the snorkel head make much of a problem? I usually have mine facing rearwards anyway.

 

[fast but dim]

that is a fantastic idea. my defender had a snorkel. i had water over the bonnet on a few occasions, but never had more than an inch in the cab.

imo you're onto somthing there mate.

 

[Roger Fairclough]

Clever idea Roger, regarding rain storms, would the small amount of rain entering the snorkel head make much of a problem? I usually have mine facing rearwards anyway.

If the head is facing to the rear, you will produce an area of low pressure at the mouth of the head. This will fight against the air trying to get into the snorkel. As the snorkel also increases the length of the inlet tube by upwards of a metre plus, this low pressure effect is further exacerbated. If you run with the head forward, you would at least be pushing air into the snorkel and this would help to counterbalance the negative effect of the increase in tube length. If you drive in the rain, the amount of water getting drawn into the system is going to depend on the severity of the rain. On the standard 70 series 3 litre engine air filter box, there is a rather involved series of plastic baffles that I believe are designed to channel rainwater or moderate amounts of wading water from the filter itself and, hopefully, back out of the system. The problem is that if a large amount of water is ingested, this system would inevitably be incapable of keeping it out of the engine.

When I tested the valve, I rigged up a hose to subject the seal to 300mm of water. Over the space of 60 seconds a few drops of water penetrated the plastic foam. This water would be vapourised by the air flow and as it would then cool the charged air from the turbo, the engine would, at least in theory, produce more power. Water injection was a method much in favour during WW2 as it could produce startling increases in power for short periods.

I realise that during use, the flow of air from within the cab will produce a lot of noise and will require a window or moon roof to be opened to replace the air being sucked into the engine but this is a small price to be paid for what I consider to be the convenience of the unit.

Thank you all for your positive comments.

Roger

 

[ModelMakerMan]

I cant believe no one has worked out the best use for this device yet; when someone lets rip in the car this will clear it instantly!

Seriously though this is a really good idea, I remember you showing me the prototype a few years ago and I was sorely tempted to make my own then. Im assuming by the looks of where it goes through the firewall in the pictures it enters the cab behind the dash? Keep in mind there is some serious suction when the engine is above 2000rpm so if there is anything near it you could loose it into the filter (my snorkel sucked an 8mm spanner off the roof when I was testing it!). Is it noisy when its open?

 

[Chris]

Sorry to say that the forward / rearward discussion has been done to death and it's been show to be utter bunkum. The snorkel is designed to meet oncoming water in the form of rain. It has a specific design including the drain holes which deal with water captured in the head. They really did spot that issue when they came to design them. Now for those who make their own out of tube and bends, I cannot say the same, naturally.

As to the rearward facing position, again just not proven to be true. You only have to put your hand over the intake of even the 4.2 with some revs on to know that there really isn't that much of a pull. It's not until you put an impermeable membrane over the whole of the head that you see an effect and even then, air is pulled in through the drains.

There was a post on here where someone took a cruiser on a rolling road and simulated wind with a massive fan with the head pointing both ways. I seem to recall that the conclusion was something along the lines of bu**er all difference. There was very conclusively IIRC no ram air effect whatsoever.

On the subject of this particular fabrication though, I have to agree that it's beautifully executed as always.

Chris

 

[Trevor]

That is a great lateral approach and love the logic - fabulous. How about the equivalent of a ballcock in the engine bay that operates the valve once the water has reached a certain level before the air intake?

Now who are the 4 forum members who will make up the Landcruiser Den

 

[Chris]

Frank, just thinking that if you went with en electromagnetic activation, would you include an indicator light to show it had switched? I'd want to be sure before I went wading that the diverter had moved.

Chris

 

[SpinDrift]

That is a great lateral approach and love the logic - fabulous. How about the equivalent of a ballcock in the engine bay that operates the valve once the water has reached a certain level before the air intake?

Now who are the 4 forum members who will make up the Landcruiser Den

I suppose with the ballcock idea is that sitting in the drivers seat in mid water, you would not know until it is too late if the ballcock jams - eg if it gets clogged up with mud and other muck.

In fact even with the valve as it is, for peace of mind, you would want positive feedback that the valve is actually drawing air from the cab. Now if it si noisy, this feedback might actually be the rush of air you would hear in the cab but has it closed completely? Which leads to my next point ...

IMO there may be a risk/limitation. The valve is a mechanical device. If it does not close perfectly (maybe because of dirt or dust has been sucked in, the control cable gets slack or whatever) and you are not moving fast enough to create a bow wave for whatever reason and the water reaches airbox height (pretty extreme depth and you could argue you should not be there in any case), that water could flow in through the normal air intake and get into the engine. So I think I would say that the extreme depth you should attempt with this valve would be just below the normal air intake height.

 

[SpinDrift]

Frank, just thinking that if you went with en electromagnetic activation, would you include an indicator light to show it had switched? I'd want to be sure before I went wading that the diverter had moved.

Chris

My very concern Chris. I guess you could go the electo route but it is more electo gubins that could go wrong.

 

[adrianr]

Id stick with manual as well - regarding wether it had opened being in the cab you'll hear the extra induction noise, now as to wether its open all the way...