Need to run hot for a while, can I stall the fan? - PeachParts Mercedes-Benz Forum

muleears · #1 11-28-2006, 01:20 PM

I have switched to Evans waterless coolant and need to "boil out" the remaining water in the system (per Evans instructions). I have covered as much of the radiator as I can and it still won't get hot enough. Can I stall the fan and if so how? Will it damage the clutch? TIA

MattBelliveau · #2 11-28-2006, 01:38 PM

Try flipping the thermostat.

rrgrassi · #3 11-28-2006, 01:56 PM

Why not take off the fan, and then tighten the bolts down, but use spacer washers or shorter bolts.

Do not flip the t-sat, cause that keeps the coolant from flowing fully through out the system.

Carrameow · #4 11-28-2006, 02:40 PM

loosen the alt and take off the belt

vstech · #5 11-28-2006, 02:40 PM

also, you will most likely not be able to get high temps at idle... you are going to have to get a load on the motor. at least hold a fast idle above 2000RPM.
John

TheDon · #6 11-28-2006, 03:27 PM

so you have to make the car go to 212.... thats brilliant.. if any coolants instructions were to do that i would have to say .. sorry not buying this crap

babymog · #7 11-28-2006, 04:00 PM

Let's see, ... 603 engine, runs well, lets see how much heat that #14 head can take before cracking, ...

Nah, I'll stick with M-B coolant and a little Water-Wetter.

The fan won't stall without damage to the viscous hub. You could restrict the upper radiator hose with a pair of pinch-clamps though, easy to overheat it that way.

When you're finished I have an '87 300D for sale in the parts section, has a good head.

vstech · #8 11-28-2006, 04:01 PM

yeah, like what's wrong with MB coolant? post the reasons for going with this waterless stuff...
anyway, if I needed to eliminate ALL water from the block, I would flush the coolant out, drain as much as possible, fill with distilled water, heat up the motor, let it stand for a few minutes, to remove heat from the exhaust manifold, then drain it all out and hook up a shop vac to the upper hose and let it run for a few hours... sure to remove all moisture. and it would not jeopardize the motor.
John

patbob · #9 11-29-2006, 04:27 PM

I looked it up because I was curious.

Seems Cal needs to get the block to 280F (138C) for long enough for all the water to boil off through the (disconnected) vent tube. 138C is going to take a while. To answer the original question, even if the '85 has the same viscous oil clutch as my '83, I don't think I'd want to stall it for that long.

Incidently, the instructions suggested draining the block and using their cooling system flush to get all the water out instead of boiling it out. That does seem a lot safer for the engine, which begs the question why wasn't this done instead?

As for those questioning why use it, the instructions I read gave two fairly good reasons: that it prevents spot overheating due to boiling coolant in internal passages, and that it allows the cooling system to be run at 0 PSI, thus preventing pressure stress. That sounds like the normal state of affairs in an MB diesel running at 80C as it is, so now I'm curious why Cal felt the need to change?

babymog · #10 11-29-2006, 05:48 PM

After spending much of my career engineering for the auto industry, I learned that engineering is nothing, marketing is everything.

As far as the 0psi saving the engine from pressure stress, how many psi is in a cylinder, oil passages, even the induction and exhaust. The pressure that is generated in a closed cooling system far surpasses the ~15psi that the cap will contain. Example: The current-production Ford Crown Vic police model has an aluminum intake manifold to the civilian plastic. The reason? At full-throttle the pressure spikes over 140psi in the coolant crossover pipe, this is from the thumping of cylinder walls (yes, cast iron does have an elastic deformity mode) into the coolant. Removing the paltry 15psi cap won't help that.

The coolant system is designed to run at pressure, works well there. It does and can boil locally, especially in a diesel where cavitation pitting is a concern with wet-sleeve engines, proper M-B coolant is designed to prevent that.

Again, I'll stick with M-B or Zerex G-05. Not knocking others' choices, just a personal decision to stick with what works and not complicate things.

rwthomas1 · #11 11-29-2006, 06:16 PM

I believe that you can use the recommended Evans flush or even use repeated flushes with RV type potable water system antifreeze.

The reason for switching to Evans are several and specific:

Water/coolant does a great job cooling up to a point. Once conventional coolant starts to boil it is a very poor conductor. Thats one of the reasons that once a vehicle starts to overheat its gets worse very quickly as the coolant vaporizes and the temps spiral out of control.

Worse still coolant can "microboil", that is, flash to steam in particularly hot locations in the cooling system, like around the exhaust valve. The steam then quickly returns to liquid when it flows through the cooler sections of the cooling system. Trouble is this can happen and there are no visible indications of overheating, just localized hot spots in the engine.

Evans is actually a less effective conductor of heat than water/coolant at normal operating temperatures. However once the water/coolant reaches boiling point it becomes a poor conductor. At this point the Evans is superior and continues to function as a "coolant".

Running zero pressure in the cooling system is less stressful on components like hoses, radiators, heater cores, etc. Obviously the engine block itself can withstand great pressures but the other components cannot. The only reason to pressurize a cooling system is to increase the boiling point of water/coolant. This offers a greater margin between the operating temperature of most engines, 190*F, and boiling point of water/coolant at 212*F Evans boils at upwards of 350*F so there is simply no reason to pressurize the cooling system.

Evans properties are such that corrosion, cavitation, electrolysis, etc. are almost non-existant.

The reality is an alloy head MB diesel is far SAFER with Evans installed than regular coolant. There is almost no chance it will overheat. Even with a compromised cooling system the temperature rise should be much slower as the Evans will continue to cool until it all leaks out. It doesn't boil off so even a reduced volume will continue to cool the engine since it won't flash to steam.

I don't have any stake in Evans and I don't even use it. I do however recognize that its a decent product should you choose to install it. Just because its different doesn't mean it doesn't work or is complicated. Properly installed, Evans cooling systems should require far LESS maintenence than conventional systems.

RT

barry123400 · #12 11-29-2006, 06:52 PM

Do a little more checking on the evans waterless coolant. I remember some specific problems a year or so ago. This information might be discredited by now and perhaps not. If you have a # 14 head on a 603 engine it might help. The otherside of the same coin is pretty risky. I completely understand some of the downfalls of conventional coolants. It is reasonable to assume the evans product is not perfect either. Few things in life really are. Find the pitfalls as well as the upsides. Now if they give you a new engine if it fails by coolant application pour the stuff to it.

Nothing like a new free 603 with an updated head etc for a little antifreeze. Excellent tradeoff in my books. The other thoughts that bears some consideration. Some mercedes have in my opinion a somewhat marginal cooling system. Thats in comparison to many if not almost all other brands of cars. There is far less lattitude to play around. You also know the heat transfer specific of evans is lower than water/anti freeze mixes. So you have to either speed up volume flow or have a much higher temperature drop across the radiator. Otherwise you are going to operate your coolant at a higher temperature in certain areas as you are not tranfering the heat away as fast now. .Your former hot spots could operate hotter. Not the ones that may have generated steam for example. ..Or you may form up a different temperature gradient from front to back of the engine.. There is enough to think about that I might try to communicate with a automotive engine cooling engineer. Many of the above thoughts that I freely admit could be totally wrong deserve some thought. Now cars that have cooling abilities of at least two times the required capacity are probably immune from a lot of these concerns. I own some non mercedes that function very well with many sub standard components in the cooling systems. They were designed to run in real desert enviroments if needed with no alterations. The manufactures seem to be staying well away from waterless coolants as well. That does not bode well for this type of product. Some of their current designs they want to run hotter than years ago..Why are they staying with the basically older type coolants? Now I see this stuff as good for track racing in many cases. Also not against new approaches but never like to be the test horse myself. Much worse if the problems are hidden or an effort is attempted to salvage something from a fundamentally wrong approach.

Diesel Fan · #13 11-29-2006, 07:35 PM

Is there anyone that has any scientifically tested data on this product? Let me answer. NO! All the information I've seen over the years on various car and motorcycle web sites invariably traces back to the claims of the seller. That's never a reliable source for information. Read there web page with a jaundiced eye. Please take note of all the claims made especially where they allude to real tests or even military trials. Then read it again and ask if your old science teacher would let you make claims like that with no proof.