Sacrificial zincs for diesel engine cooling system-gctid343344

[Guest]

We have recently purchased an 1989 4588 Bayliner with twin Hino diesel engines - wondering if we should have zincs placed inside the cooling system - any help on this? We have been told by friends that we should have these, but there is no mention in the engine manual. Thanks alot,

[kwb]

As much as it pains me to write this - I don't think it helps with the common failures with manicoolers.

The design is a terrible mis-mash of materials begging for problems but as I understand the design the salt water side drains when engine is not running so the time where you have a conductive electrolyte is actually pretty minimal. Based on the teardown of my coolers indications inside confirmed that the seawater does drain almost completly.

I just did a lot of reading about peoples failures of manicoolers (which I was getting close to a failure myself) and my general opinion is that casting quality is inconsistent - my hunch on this is that the original tool was a multi-cavity arrangement and not all the sections of the mold filled/cooled the same. When you couple hot runners out of the exhaust manifold, a semi-porous casting (or at least less than ideal grain structure), and coolant that does not have inhibitors to prevent microboiling you end up getting pitting that I think often gets attributed to the assortment of dissimilar metals.

[Arizona_Bob]

I have looked at my shop manuel and it does not show anywhere that there are factory installed zinks on either the 175hp or the 220hp

turbo hino engines. Maybe Earl ( MR HINO)will chime in if he knows of anything different. Hope this will help.

Bob

[kwb]

Correct no zincs in the engine. Some trans coolers may have them depending on po replacement