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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: RickB on June 01, 2009, 06:23:32 AM

Title: Recommended DD two stroke antifreeze/coolant??
Post by: RickB on June 01, 2009, 06:23:32 AM
Hey folks,

I was looking at a blog today where sean mentioned a "special diesel coolant" and he made a distinction between that and cheap antifreeze. I have never heard that we are supposed to be using anything other than 50% coolant mix of green over the counter antifreeze.
So, is there a "special" antifreeze for our motors??

He also mentioned it was expensive. Having just done my entire cooling system I found the green stuff gets fairly costly when you are talking about 10+ gallons.

Thanks,
Rick
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: luvrbus on June 01, 2009, 06:37:24 AM
Rick, nothing special about about the antifreeze in a 8v71 just a Ethylene base with low silicate drop out and keep your system in balance green stuff is fine has been since 1939 no need for the pre charged extended life antifreeze at over 20 bucks a gal. FWIW DD dealers sell both types    good luck
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: gumpy on June 01, 2009, 06:46:41 AM
If you put in new over the counter antifreeze such as Prestone, you should pick up a jug of the DD additive and add to your system. JD has it.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Lin on June 01, 2009, 08:49:35 AM
My understanding is that diesels can have a problem with cavitation in the coolant system actually destroying the engine.  To avoid this, one can add a Supplemental Coolant Additive (SCA).  The one I have used is called Napa Kool, obviously from Napa.  There are others available too.  Cavitation may be more of a problem with wet liners than dry, but I use the stuff anyway.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: JohnEd on June 01, 2009, 11:11:28 AM
The DD shop up in Coburg, Or. has a liner on the counter that was taken from a 8V92(same as 6V92) and it looks like a piece of Swiss Cheeze.....no kidding!  It is full of these little holes and channels and one has gone completely through the liner.  These engines NEED low silicate antifreeze specified for two strokes.  In all the time I have been reading this board, this is the first time I noticed anything about an additive to auto grade antifreeze that makes it compatible with 2 stroke wet sleeve engines.  I am no chemist but I still don't think adding something will eliminate something like silicone.  In my limited understanding, there are three types of antifreeze....auto grade, Diesel and two stroke diesel.  I hope that someone that knows will clear this up for me.

John
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: kyle4501 on June 01, 2009, 11:46:31 AM
The 71 series are dry sleeved engines. Quite different than the wet sleeves of the 92 series.

Or, so I'm told . . . .
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: luvrbus on June 01, 2009, 11:56:09 AM
JohnEd, i think someone is pulling your leg only 2 inches of the 92 series liners come in contact with the coolant the rest is dry   

good luck
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Lin on June 01, 2009, 01:27:14 PM
Another thing to worry about.

http://www.arrowheadradiator.com/cavitation,_scas_and_the_proper_maintenance_of_diesel_engine_cooling_systems.htm
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: MCI-RICK on June 01, 2009, 02:05:32 PM
Lin,

Real informative link on -  Cavitation, SCA'a and the proper maitenance of diesel engine cooling systems.

I saved that for future reference.  Thanks.

Rick
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: jackhartjr on June 01, 2009, 02:17:05 PM
Soo...if I read that right us 2 strokers don't have to worry about cavitation???
If so what do we want to use, any ole green antifreeze?
Jack
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: gus on June 01, 2009, 08:01:04 PM
Only green existed when most, if not all, 71s were born so there is no point in using anything else, especially if it is expensive.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Airbag on June 01, 2009, 08:59:32 PM
How many of us are using distilled water?
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: jackhartjr on June 01, 2009, 09:34:34 PM
Airbag, are you saying disstilled water only with no additives?
Thanks
Jack
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Airbag on June 01, 2009, 10:08:58 PM
Quote from: jackhartjr on June 01, 2009, 09:34:34 PM
Airbag, are you saying disstilled water only with no additives?
Thanks
Jack

No I mean to mix with the anti freeze. I am not using it but when I do a flush I think I will. It has no free oxygen molecules to corrode anything. I can attest to that I have some in an aluminum tank for years now and not speck of corrosion.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: jackhartjr on June 01, 2009, 10:14:41 PM
Thanks, I appreciate that info!
Jack
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: luvrbus on June 02, 2009, 06:00:10 AM
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
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Van on June 02, 2009, 06:28:19 AM
25 Cents ? sounds good to me !  ;)
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: gus on June 02, 2009, 01:29:02 PM
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.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Utahclaimjumper on June 02, 2009, 02:09:58 PM
I've had and operated my 8V71 for 11 years with distilled water and zero silicate anti-freeze 50/50,,,works for me.>>>Dan
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: WEC4104 on June 02, 2009, 02:40:03 PM
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.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: luvrbus on June 02, 2009, 03:53:21 PM
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
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: Lin on June 02, 2009, 06:20:45 PM
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.
Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: WEC4104 on June 02, 2009, 06:23:42 PM
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.

Title: Re: Recommended DD two stroke antifreeze/coolant??
Post by: niles500 on June 02, 2009, 11:48:38 PM
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