Cold water

[custard]

Hi

BM's are new to me, always had water cooled bikes.

This mite seem like a stupid question, and I know that the bikes are designed for this, but...

For example, riding along, hot engine, then you do a flowing cold water crossing, does all that cold water splashing onto those sticking out cylinder heads not case damage.

 

[Engineer]

Hi

BM's are new to me, always had water cooled bikes.

This mite seem like a stupid question, and I know that the bikes are designed for this, but...

For example, riding along, hot engine, then you do a flowing cold water crossing, does all that cold water splashing onto those sticking out cylinder heads not case damage.

I would think that very sudden cooling of a very hot engine with copious amounts of cold water may cause damage due to differential (negative) expansion between the outer parts and the still very hot inner parts - if you see what I mean.

I would avoid splashing lots of cold water on a hot engine.

 

[camel_landy]

In other words....

Think of going out for a long run and then, when you're hot and sweaty, jumping into a cold plunge pool. Can you imagine that sharp intake of breath as your balls hit that cold water??? Well, that's what your engine, gearbox & drive train are going to do and if they're submerged, they're going to be sucking in water!!!!



M

 

[Spout]

Water tends to be only a couple a degrees colder than the surrounding air anyway. So no temperature problems as such.
Water getting in where it shouldn't is the bigger problem.

 

[MIKE R]

Hi

BM's are new to me, always had water cooled bikes.

This mite seem like a stupid question, and I know that the bikes are designed for this, but...

For example, riding along, hot engine, then you do a flowing cold water crossing, does all that cold water splashing onto those sticking out cylinder heads not case damage.

Heavy rain

 

[Bones]

Water tends to be only a couple a degrees colder than the surrounding air anyway. So no temperature problems as such.
Water getting in where it shouldn't is the bigger problem.

It may only be a couple of degrees cooler but it will have a much greater cooling effect. Imagine the differnce between having cool air blown at you and having cool water thrown at you.

The cooling effect of say riding through a ford with a hot bike engine is one of the reasons why air cooled engines run bigger tollerances.

 

[Bones]

.

I would avoid splashing lots of cold water on a hot engine.

Would you ride your bike in the rain?

 

[Engineer]

Water tends to be only a couple a degrees colder than the surrounding air anyway. So no temperature problems as such.
Water getting in where it shouldn't is the bigger problem.

Time to dig out my Physics books - but I believe that the rate of heat transfer from a hot engine to water will be much greater than to air even if the air and water are at the same temperature.

 

[Engineer]

Would you ride your bike in the rain?

Rain has far less water in it per unit volume than does a river, so the cooling is far far less rapid than when riding through a river.

 

[Bones]

Rain has far less water in it per unit volume than does a river, so the cooling is far far less rapid than when riding through a river.

Well I remember one storm on the way to Assen....

And then there is all the water flying off the wheels, the bow wave when riding through puddles etc

 

[terayon]

So nobody ever put their hands on the engine casing during winter to keep warm.

The casing doesn't get that hot, the oil cooler help to keep inside temp to a minimum.
You'll find the boxer engine stays a hell of a lot cooler than any water cooled bike, unless your going to be sitting in traffic for 30 mins.

 

[LiquidLAN]

Hi

BM's are new to me, always had water cooled bikes.

This mite seem like a stupid question, and I know that the bikes are designed for this, but...

For example, riding along, hot engine, then you do a flowing cold water crossing, does all that cold water splashing onto those sticking out cylinder heads not case damage.

hummm word of warning... don't do it!

forget all the answer about negative heat expansion, if you are going through water deep enough to cover the cylinder heads you are going through water deep enough to run the risk on water induction and hydrolic lock.

There are plenty of people on here that will tell you it's not a problem but I and at least one other person here has ended up with a bike in the dealer for a long time and a large expense after water induction.

IMHO, there are a couple of major design flaws with this bike in this department, firstly the snorkel faces forward and will catch a lot of the water that washes over the lower front yoke, secondly the air intakes are directly below the air filter (any water the gets in flows stright into them), thirdly there is an engine breather pipe at the bottom of the air box, any water that misses the cab intakes and goes into the box will automatically drain into the sump.

Be warned, its expensive if you get it wrong.

 

[LiquidLAN]

So nobody ever put their hands on the engine casing during winter to keep warm.

The casing doesn't get that hot, the oil cooler help to keep inside temp to a minimum.
You'll find the boxer engine stays a hell of a lot cooler than any water cooled bike, unless your going to be sitting in traffic for 30 mins.

why would I do that I've got heated grips

oh and a luverly Giali heated jacket (picked it up Monday - Excellent purchase)!!!

 

[terayon]

aaahhhh so have I. But when your sitting around in the winter waiting for your mates cause they're late as usual, you put your gloves on the cyliders as well as your hands and it's warm enough to keep you warm without being too hot and burning

 

[Engineer]

So nobody ever put their hands on the engine casing during winter to keep warm.

The casing doesn't get that hot, the oil cooler help to keep inside temp to a minimum.
You'll find the boxer engine stays a hell of a lot cooler than any water cooled bike, unless your going to be sitting in traffic for 30 mins.

Parts of the cylinder head get extremely hot in normal running, particularly the area around the exhaust valves - a small amount of splashing water is obviously not a problem, but large amounts of cold water on the hottest parts of the engine while it is running is probably not a good idea.

As others have said, a bigger problem is the possibility of sucking water into the engine while riding through deep water. The air intake seems to be in a stupidly low position on the GS, I wonder why BMW placed it so low down.

 

[jetjock]

Hi

BM's are new to me, always had water cooled bikes.

This mite seem like a stupid question, and I know that the bikes are designed for this, but...

For example, riding along, hot engine, then you do a flowing cold water crossing, does all that cold water splashing onto those sticking out cylinder heads not case damage.

Just remember guys ,these engines are not just air cooled but oil cooled as well so the temp drop is not as much as you think!!

 

[Eastriding2002]

You could always wait for 1/2 an hour prior to riding through any puddles I guess.

 

[bonox]

You could always wait for 1/2 an hour prior to riding through any puddles I guess.

for those of us with 1200's, will that extra 1/2 make the water level go down?



I've not yet seen or heard of problems with throwing high performance air or oil cooled mx bikes into cold water up to their gills. And they are much harder worked (and tuned) than our tractors.

 

[Marty Gutenfart]

Well I remember one storm on the way to Assen....

Would that be 1996/7 ish? Feck me did it rain!

 

[Bones]

Would that be 1996/7 ish? Feck me did it rain!

That would be the one. Like riding through a waterfall, for an hour! The 1200 Bandit didn't miss a beat. My gloves are still wet though.