Painting Liners

[triumphman]

In the manual for the JK6 it states to paint the outside of the liners before installing, I am intending to run antifreeze - corrosion inhibitor. Is painting them still recommended and if it is what is the best type of paint.

[dieselgman]

Hopefully someone with JK6 specific experience will fill in the gaps here... I know on the SW and HRW marine series that the water jackets were very problematic for corrosion and they did not use liners so the entire cylinder assembly would become unuseable once heavy corrosion took its toll. I think you are on the right track thinking about corrosion protection. You may also need to consider the effects of detonation on the cylinder liners, a result of intense vibration and entrained air bubbles in the coolant - usually controlled in modern engines with a coolant additive sometimes referred to as SCA or Nitrates. Iron and steel assemblies would be affected such as water pumps and cylinder liners especially.

dieselgman

[triumphman]

Thanks for that there is deep pitting and I think that this is caused by cavitation is this the same thing, some modern wet liner engines use "super coolant" and i have been offered some of this by a friend. I  suppose thats whats making me think would I be better cleaning the liners and leaving theme bare if using this.

[dieselgman]

Yes, cavitation is the same thing I described that is corrected with modern SCA coolant additives. You can buy the additive and supplement just about any glycol mixture. You can also easily get test kits that tell you the concentration and viability of your mixture.

dieselgman

[triumphman]

So dont paint them get them all clean and shiny and use modern coolant ??

[dieselgman]

As far as I understand it, painting the liner is a weak and ineffective method to control or stop cavitation. It may be fine for reducing or controlling chemical corrosion however. I have seen Zinc Chromate based paints used in marine environments for this purpose. Maybe you can approach the issue from both angles that we have discussed. If your parts already show significant decay, it is only sensible to do everything possible . I hope someone else who has worked more with the Lister marine engines can chime in here.

dieselgman

[dieselgman]

Also, the coolant additive mixture should be completely effective whether you have another protective layer on those liners, or not. It is the micro-bubble implosion against the liner or other part that causes the erosion in a case of poor coolant performance and cavitation etc..

dieselgman

[mike90045]

paint will impede the thermal transfer from liner to coolant.  And i don't see how paint can prevent cavitation erosion of steel.

[richardhula]

Pinched from someone else's reply to the same subject with JP/JK liners & apparently taken from the Lister manual.

May shed some light on the issue if you intend to operate the engine with direct sea water cooling.

[triumphman]

Thanks for the reply's looks like they are going in bare then.