Recommended DD two stroke antifreeze/coolant??

[luvrbus]

you guys can waste your money on distilled water if you chose but it is not necessary, in my manual it states you can use any clean water but DD says not to use ditch water. Living in AZ where you cut the water with a knife I do use R/O water in mine.   good  luck

[Van]

25 Cents ? sounds good to me ! 

[gus]

I once read that distilled water does not mix well with green anti-freeze since it is a mechanical mix instead of a chemical mix.

Don't remember where I read it but it makes sense.

[Utahclaimjumper]

I've had and operated my 8V71 for 11 years with distilled water and zero silicate anti-freeze 50/50,,,works for me.>>>Dan

[WEC4104]

Hmmmm. This thread has more diverse opinions regarding coolants than I expected.

Usually when similar topics surface, someone is usually quick to quote "chapter and verse" from Da Book, or other credible DD source.   This generally trumps and comments that begin "My Uncle Barney always told me to use..."

So, I'll reference the following document direct from Detroit Diesel:

http://www.detroitdiesel.com/Public/brochures/7SE298.pdf

It specifically recommends that distilled or deionized water be used. If another water source is going to be used, it lists an entire chart with tests for hardness and presence of other minerals to help determine if the source is suitable.

It also specifically states that automotive type antifreeze products are not to be used, based on the fact that they generally contain high phosphate and silicate levels.

Lots more info in the 31 pages for your reading enjoyment.

Personally, my 6-71 gets a cocktail of DD Power Cool and distilled water.  Shaken, not stirred.

[luvrbus]

wec4104 ,were does it mention a 71 using distilled water  I'll get Doyle to post a page from my  92 series manual dated 1988 and you can read it.This was never a issue when GM owned DD.I have owned 2 strokes for over 30 years in equipment, trucks and buses and have never lost one because of water or antifreeze and I always followed DD specs of old not the new where M/B is trying to sell you 20+ dollar a gal antifreeze.I  buy ny green from Stewart and Stevenson.Read section 13.2 5 pages on water and antifreeze by GM not M/B     good luck    

good luck

[Lin]

I think whether to use distilled water or not is not a live or die decision for your engine.  However, it would seem to just make sense to use water that will not deposit minerals in your radiator.  Less mineral deposits, better flow, heat transfer and radiator life.

[WEC4104]

On page 13 of the cited document, there is a section entitled "Water Requirements". It states that distilled or de-ionized water is what they prefer you use. It spells out that tap water is can be okay, if it meets the established limits for total hardness, and the PPM of chlorides, sulfates, and total disolved solids. It cautions that some tap water can cause scaling, sludge deposits, and/or corrosion, leading to water pump failures, poor heat transfer and overheating.

The fact that you have 30 years of good experience might indicate that the tap water in your area is perfectly fine. For someone in another part of the country ...who knows?    Last I checked, DD doesn't sell distilled water so I'm thinking this is not a Marketing driven recommendation.  

I have no idea what the specs are on "ny green from Stewart and Stevenson", but if it is low in phosphates and silicates, it is probably okay to use.

[niles500]

Minerals contained in "hard" water (tap as opposed to distilled) may not be a problem in a sealed system (non-evaporative) operating below actual (a differing # of degrees based on additives, alltitude, etc.) "boiling point" - But an unsealed system (evaporative) or a system operating above boiling point and mixed with air will allow the minerals in the water to distillize and deposit themselves on the system's surfaces - The moral of this story ..... if your sure your system is 100% sealed and operating under boiling point, then tap water is safe - if not distilled water is cheap insurance - FWIW

For you chemists out there - I know this has been oversimplified