Using NAPACool in your Diesel?

[BrianW]

Anyone else using this coolant additive in their diesel engines? I picked up a quart, and a coolant test kit, and plan on making sure my coolant is good to go. Going to do the same for the aux engine too.

Thanks

[Bob Smalser]

Sure. Best done with a coolant filter, too. Talk to long-haul truckers about it, as most big rigs have them.

Rusting through the cylinder liners often happens long before rings and pistons are needed....

...it passes the common sense test.

[imported_Dutch]

my diesel is air cooled - now there is some common sense smile.gif

[Bob Adams]

I'm running Rotella premium premixed antifreeze in my Detroits. At $8.00+ a gallon (and you cannot dilute it), it better bloody NOT rust out my liners!

[Dan Lindberg]

This sounds close to a classic North - south difference in thinking.

Years ago I was part of a design group designing a new line of diesel engines. (Onan/Cummins) Any way, the company leaders decided the engine was going to be built at an existing plant in Alabama. As they started getting engines off the line and shipping them, they started getting reports of oil cooler/cover failures. We couldn't understand why and couldn't figure it out, we never had any problems with them in development.

So we had them send us some, turns out they were cracking the covers and cooler welds, which was strange because they were OK when shipped, as all engines were run about 1 hour.

Being down south, the assembly folks used straight water as coolant and drained the engines from a block drain. This resulted in coolant (water) being left in the coolers/covers, which froze and cracked the covers when the trucks got in the Northern states.

Being Northerners, we never even considered that folks wouldn't use antifreeze for coolant.

Keep antifreeze with a good, maintained additive package in the cooling system, and I suspect there will be few rust problems.

Dan

[BrianW]

Thanks gents. I'm going to get down to the boat today, warm up the engines, then use the test strips to see how everything is doing.

Heck, I thought coolant was needed to keep certain water pump bearings lubricated, if nothing else. Just can't imagine running straight water.

[sdowney717]

Did you know that antifreeze actually lowers the efficiency of the heat exchanger?
The more concentrated the worse it gets.
I have been using water pump lubricant and antirust additive in a bottle from the auto stores for years.
When I have occasionally pulled things apart so far no rust. I went to this because I was having some overheating issues using antifreeze. You dont get any freeze protection so in the winters I put a 60 watt light on in the bilge. We dont get super cold here and no bilge freezing even down to the low 20's with the light. Of course it warms up during the days to low 40's in the winter.

[carioca1232001]

sdowney717 wrote:


Did you know that antifreeze actually lowers the efficiency of the heat exchanger?
The more concentrated the worse it gets.
The thermal capacity of glycol-type antifreeze is some 65% of that of plain water.
on this consideration alone, a mix of antifreeze+water would therefore attain a higher temperature per unit of heat energy absorbed form the engine, than pure water by itself.
In a closed cooling circuit with heat exchanger and coolant circulation pump, this in turn would cause the thermostat to open up earlier.
All in all, the heat transfer to the surroundings (raw water) would be more dynamic and there would be less chance of over heating.
Right or wrong ?

[sdowney717]

Compared to plain old water antifreeze mixtures inhibits the heat transfer.
From my motor manual
'Dont use more antifreeze than is prescribed for temperatures to be encountered. Extra antifreeze only reduces heat exchange values and causes greater expansion.'
I have personally experienced this. When I first got the boat, I used a 50% mix of water and ethylene glycol. The motor was running much too hot. So I researched it and tried plain water, then it ran at normal temperature. Perhaps my heat exchangers are not perfect and I needed that extra margin to run at normal temperature. Now I just use a rust inhibitor and water pump lubricant.

[sdowney717]

http://www.batterystuff.com/cooling/redline/water_wetter.htm
Interesting quote
'Water has twice the heat transfer capability when compared to 50% glycol antifreeze/coolant in water.'

[NormMessinger]

Dang! Wrong again. I recently picked up a hint that I had things backwards but filed it away without action since for nearly 60 years I knew 50/50 preston was a better coolant than plain water. Maybe that was only in Western Kansas. Now ya'all are pretty much confirming that it twernt so. Never mind, I'm not to old to change should I ever again be in an area that doesn't have descent winters.

[carioca1232001]

sdowney717 wrote:


Compared to plain old water antifreeze mixtures inhibits the heat transfer.
From my motor manual
'Dont use more antifreeze than is prescribed for temperatures to be encountered. Extra antifreeze only reduces heat exchange values and causes greater expansion.'
I have personally experienced this. When I first got the boat, I used a 50% mix of water and ethylene glycol. The motor was running much too hot. So I researched it and tried plain water, then it ran at normal temperature. Perhaps my heat exchangers are not perfect and I needed that extra margin to run at normal temperature. Now I just use a rust inhibitor and water pump lubricant. Judging from your post above, it would seem that there is a great deal of FINE DETAIL that gets masked when judging solely on the merits of the 65% lower heat capacity of glycol vs. pure water.

In my fuel-injected 1.8 petrol VW 4-cylinder car engine - derived from the Audi LS 80 engine of the mid- 70´s - overheating is generally the case if the glycol is left out, or engine run at less than 20:80 (glycol:water)

And PURE GLYCOL was the de facto coolant in high performance piston-engine aircraft engines in WWII.

Also 40:60 (glycol:water) in the twin turbo-diesels (DIY marinization) on my boat makes them run cool. The glycol vendor warns me not to exceed the 40:60 (glycol:water)ratio, for risk of incurring the law of diminishing returns. I have not tried to defy him !

What some people strongly recommend is adding an ANTI-PITTING additive to whatever coolant is being used in HEAVY DUTY SERVICE diesels .

I believe that wet-liner diesels like in my MWMs (German)are particularly prone to liner pitting, until they get eventually holed. The head mechanic at the local VW trucks outlet (MWM powered) has actually shown me holed liners arising from this phenomenon.

This apparently, has to do with an ultrasound-type wave that is given birth at the time of oil-injection-combustion, which creates tiny voids (air pockets) in the space surrounding the wet-liner, consequentially leading to local vaporization of coolant, boiling, hot spots etc. etc. more or less in that order.

Sorry to bore you, if I have !

[sdowney717]

Cavitation corrosion can also occur on propellors where little tiny air bubbles explode on the prop surface creating pits. So the water does not have to be hot.
Water under sufficient force is very powerful. You can even drill thru solid rock using high pressure water.

[sdowney717]

Good article explaining wet liners and their special coolant requirements
http://www.farmersinfo.com.au/pages/features/machine/castrol05.htm