Engine Coolant

Recently, I started a topic called “Cylinder Sleeve Removal / Installation” to provide an instruction for doing the job. Upon removing the cylinder sleeves, I noted that there was significant build up of lime like deposits and under the deposits was significant rusting. Both the scaling and rust build up was easily removed from the surface of the main portion of the sleeve, but I also found minor porosity at the o ring sealing areas of the sleeve.

 
Picture of a removed sleeve as found

The interior of the cylinder block was found in excellent condition and needed nothing more than a reasonable cleaning especially in the o ring sealing areas primarily due to a build up of some kind of sealing goop that Kawasaki used during the installation of the sleeves into the aluminum block. My concern is based on the scale build up and rusting of the sleeves. Why was the rest of the coolant system in good state of repair and the sleeves showing significant corrosion? I went back to the Factory Service Manual to see if there was a spec on the coolant and found it on page 203 of the manual.

 
 
 Kawasaki calls for a “coolant containing corrosion inhibitors made specifically for aluminum engines and radiators” and this is where I feel Kawasaki missed the boat. When Kawasaki design built the KZ1300, Z1300 and the ZN1300, they opted to build the cylinder block with a wet sleeve design. To the best of my knowledge, this was the first and only use of the wet sleeves in any of their engines. Most aluminum cylinder blocks with cylinder liners are cast in place liners, meaning that the aluminum block is cast around a cylinder liner and therefore the aluminum bonds to the liner and shields the liner from the coolant in a water cooled engine.

 Wet Sleeved engines are typically industrial diesel engines and also larger diesel engines found in semi -trucks. The purpose was to provide better cooling of high horsepower engines and also the ability to rebuild an engine block by replacing the cylinder sleeves and pistons instead of boring out the cylinders and using oversized pistons.

One of the problems with wet sleeves was pitting corrosion on the exterior of the sleeve on the thrust side of the sleeve. Investigations determined that during the combustion process, the sleeve vibrated at a frequency very similar to what happens in an ultrasonic cleaner and the coolant surrounding the sleeve acted like the fluid in an ultrasonic cleaner causing cavitation bubbles to form and collapse on the liner, eroding the surface of the liner. Eventually, pit corrosion would turn into pinholes and migrate through the liner, causing a coolant leak into the cylinder as evidenced by white smoke.

That was the problem that needed to be addressed. There are a couple of ways to address the corrosion issue, one being an anti-corrosion coating on the exterior of the sleeve. Darton Sleeves are a prominent manufacturer of wet sleeves for converting engine blocks with cast in liners to a wet sleeve block primarily for racing engines. Their Modular Integrated Deck (MID) sleeves have a Phosphate coating applied to the exterior of the sleeve to combat corrosion. Darton also recommends using Evans coolant but do not specifically tell you which coolant Evans produces to use. Evans coolant comes in several different types depending on use. There is Evans High Performance Coolant, Evans Heavy Duty Coolant, Evans Powersports Coolant and different versions of their Evans NPG coolants for racing applications. 

This leads me to the second way to address the pitting issue and that’s the coolant used. Since the primary use of wet sleeves was in diesel engines ASTM D-6210 or RP-329 by the Technology & Maintenance Council (TMC). This antifreeze is sold with an SCA package already blended in, typically including nitrate to protect iron and steel, tolyltriazole to protect copper and brass, borate or phosphate to buffer acids (formed as glycol breaks down), silicate to protect aluminum and nitrite (sometimes accompanied by molybdate) to form a cavitation-resistant barrier on sleeves. 

Kawasaki only required an antifreeze designed for aluminum engines and radiators so they basically forgot to account for the cylinder sleeves which are ductile iron. As noted above, diesel engines with wet sleeves need a nitrate additive to ward off corrosion of the sleeves. 

I also sent off an email to Evans asking them which of their coolants to use for engines with wet sleeves to which they replied,
John. Sorry about not seeing your email. HD coolant has an additive for steel parts that contain commercial diesel engines. I  don't think that your engine has the same parts. But you can use the HD if you prefer, It is the same coolant as the HP but with more additives for steel parts.
Guy 
My interpretation is that Evans HDC coolant was designed for engines containing ductile engine components and is more likely a better choice for the KZ, Z, Zn 1300 engines. 

In the last 10 years there has been development of coolants called “Extended Life Coolants” which are a group of coolants designed to accommodate what happens to coolants in engines with wet sleeves. Typically, the additives in wet sleeved engines will plate out on the sleeves to protect the sleeves from corrosion and this depletes the additives in the coolant. Part of the maintenance of diesel engine coolants requires topping up the additives every couple of years to replenish the depleted additives. Another group of long life coolants is the newer Organic Acid Technology antifreezes which use a completely different technology to address corrosion including aluminum, copper, brass, lead and iron, so similar to Evans HDC coolant, would also have additives to accommodate the ductile iron liners of the KZ,Z and ZN engines. 

That’s my research findings to date. Hopefully this might change your mind as to which antifreeze to select and why you would want to do this.

 KB

This is a pic of my 6 liners. 5 have been cleaned up and 1 was in the state as found when pulled from the cylinder block.


This pic shows the o ring sealing area around the bottom of the sleeve where 2 o rings are meant to seal. Pitting is evident and I am looking for ways to "fix" the pitting. Still doing research on this aspect.


O rings are meant to seal in the 2 areas as marked

I subsequently emailed Evanscooling.com which is a different outlet with a technical department and asked the question again.
I have a 1980 Kawasaki KZ1300 motorcycle with wet sleeves . What coolant would be more appropriate knowing that it has wet sleeves, Powersports coolant, HDC coolant or High Performance coolant"
and got this response.

"John:
In this instance the High Performance would be used over PowerSports. Heavy Duty was incorporated into High Performance and dropped a few years back to solve this confusion and only have one coolant for Auto and Diesel applications.

Thank You
Dave Wright


--
Dave Wright
Technical Sales Manager
Evans Cooling Systems Inc.
T: 888-990-2665 x207

So bottom line- If you choose to use Evans Coolant , you want to use the High Performance  version of Evans to get the rust protection for the sleeves.
And this also reinforces the thought that a coolant designed for diesel engines would be more appropriate for our engines than a coolant designed for aluminum block engines.

Really good work KB.

Looking at my order, I bought the PowerSport stuff. Will get this instead. Clicky
I'll run the PowerSports stuff in my DL650.

D
 

Not to distract form the topic of "alternative" coolants, I'll go on record by stating that I've always changed my coolant every 2 to 3 years with a 50/50 mix of a Brand name made for Aluminum systems and the inside of my 44 yr. old radiator is Pristine !