Engine Zinc's...are they necessary?

[baldpaul]

I am looking for opinions. I have twin Perkins 225ti engines. I don't use pencil zinc's in the exchanger. A boat yard I used told me they don't recommend them as they have actually seen more problems caused by zincs plugging the tubes when the zinc deteriorates and begins breaking apart. They said as long as my engines were properly bonded to the main system, which it is, then zincs were not necessary. This runs contrary to what is commonly suggested. Does anyone have any comments on this?

 

[Edelweiss]

I am looking for opinions. I have twin Perkins 225ti engines. I don't use pencil zinc's in the exchanger. A boat yard I used told me they don't recommend them as they have actually seen more problems caused by zincs plugging the tubes when the zinc deteriorates and begins breaking apart. They said as long as my engines were properly bonded to the main system, which it is, then zincs were not necessary. This runs contrary to what is commonly suggested. Does anyone have any comments on this?

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I guess they're banking on the cooler and tube bundle being bonded to the engine?

Many of these boat shops get strange ideas and they pass it on to their workers and customers. Just like this forum you have to be careful with what they tell you and sort out the bad from the good information.

Years ago, a prominent marine shop here changed my oil and put 5 gal of oil in each of my engines (Perkins says they should hold 2.5 gal), and I saw it on the invoice. Their mechanic swore up and down that he knew these engines in and out, because of the oil cooling system they need more oil and you had to check the oil with the engines idling. Finally we called the perkins distributer to get it straightened out. They ended up pumping 2.5 gals out of each engine and no you don't check them idling.

I would be suspicious of that assumption on the zinc. My tube bundle is isolated by the hoses, bracket rubbers and gaskets. I haven't checked it out with VOM meter yet, but I'm not going to risk my $600 copper- nickel tube bundle just to save $2 worth of zinc. There is a reason your cooler zinks go away in a few months. IMHO, It's like buying insurance, just change the zink out before they fall apart.

Larry B

 

[psneeld]

they are full of it...the only problem WITH using zincs are if you let them deteriorate to the point of disintegrating in your exchanger...which in a perfect world SHOULDN'T happen..but sometime does. If it looks like they HAVE fallen apart...even then it isn't the end of the world as most exchangers can have a few tubes blocked and still cool fine (especially if you aren't running them at full rated power all the time).

the results of NOT using zincs are a lot better documented (and costly) than using them.

 

[RickB]

The prudent mariner will follow the manufacturer's advice. MTU, for example, provides the following:

"The entire cooling system must be free of zinc components. This also applies to coolant supply and return/drain lines as well as to storage bins."

 

[psneeld]

The prudent mariner will follow the manufacturer's advice. MTU, for example, provides the following:

"The entire cooling system must be free of zinc components. This also applies to coolant supply and return/drain lines as well as to storage bins."

What exactly does that mean? Not using zincs when a manufacturer calls for them or just making sure passages aren't blocked because of deteriorated zincs????

 

[Max Simmons]

There are no pencil zincs in exchangers on my Perkins 135's

 

[jleonard]

The range 4 Perkins do not come with zincs as far as I know from my many years on the Mainship group forums. This had been talked about many times in that venue.
My old T6.354 had a zinc in the heat exchanger.

 

[Tom.B]

The range 4 Perkins do not come with zincs as far as I know from my many years on the Mainship group forums. This had been talked about many times in that venue.
My old T6.354 had a zinc in the heat exchanger.

Yep, mine does. I try and change it often, but sometimes forget until it's gone.

 

[RT Firefly]

Greetings,
Mr. psneeld. I think Mr. Rick B.'s post is self explanatory. In the case of MTU engines NO zinc ANYWHERE, including sacrificial anodes, in the cooling system. Following the manufacturers guidelines, as always, is the key.

 

[rwidman]

My Volvo has no sacrificial anodes. That's how it was designed.

 

[psneeld]

Greetings,
Mr. psneeld. I think Mr. Rick B.'s post is self explanatory. In the case of MTU engines NO zinc ANYWHERE, including sacrificial anodes, in the cooling system. Following the manufacturers guidelines, as always, is the key.

You're right...I just read it too fast.

I know some engines and components do not have zincs and some do...if it was designed to have them...I certainly would as the OP was questioning...not "guessing" like he was advised that zinc pieces are a bigger issue than no zinc.

 

[Marin]

Yep, mine does. I try and change it often, but sometimes forget until it's gone.

Our FL120s have only one zinc and it's in the main heat exchanger. We change them every six months or so, at which point they are fuzzy but only about half to two thirds gone. I write the date the new one was installed on the bronze cap of the zinc with a Sharpie so I always have a reminder of when it was installed when I do an engine room check.

 

[mattkab]

The range 4 Perkins do not come with zincs as far as I know from my many years on the Mainship group forums. This had been talked about many times in that venue.
My old T6.354 had a zinc in the heat exchanger.

Sorry to ressurect an old thread -- but I worked on my engine over the weekend doing basic maintenance (oil, filters, belts, etc) and tried to find the zinc annodes to replace -- couldn't find any! I have the workshop manual, and it doesn't list any zinc locations or part numbers either.

Came to this forum to search for hints to where they could be, and came across this previous post. Is it really possible that there are no zincs at all?

My powerplant is a Perkins Range 4 MT200TI.

 

[healhustler]

My Yanmar 4LH series had no zincs. I lost the innards to my intercooler and perforated my tranny cooler at 340 or so hours. The engine is bonded. Talking to Yanmar, the acknowledged the engine was sold that way, but added that a zinc in both coolers would help in the salt. The Yanmar parts source in Stuart, FL said that it was a "fresh water only" engine. The seller in Ft. Lauderdale said "That is a hell of of thing to tell a user about an engine series that I hold many warranties on", and that any engine he sold with a raw water pump was a salt engine. Regardless, I'm keeping an eye on the pencil zincs and have had no other issues. I haven't found any other zincs anywhere, but I've always felt insecure about these differing opinions.

 

[rwidman]

There are no anodes in or on my Volvo engine.

 

[Codger2]

Is it really possible that there are no zincs at all?

If memory serves me correctly, my buddy's Bayliner 4588 with Hino engines didn't have any zincs either. Is there a Bayliner 4588 owner out there that can confirm/deny this?

 

[River Cruiser]

If memory serves me correctly, my buddy's Bayliner 4588 with Hino engines didn't have any zincs either. Is there a Bayliner 4588 owner out there that can confirm/deny this?

Hinos don't use zincs, the tubing bundle is isolated from the manicooler with orings.

 

[sunchaser]

I have twin Perkins 225ti engines. I don't use pencil zinc's in the exchanger.

I have the same engines in my DF. No zincs are required. The Perkins Sabre books are very complete - you'll note no mention of engine zincs, this is not an oversight.

One other thing to keep in mind, the PS 225TIs (when painted yrellow they are the Cat 3056) have after coolers that need some checking from time to time. Unless you have the shop manual, this is not noted as a maintenance effort in the owner supplied manuals, it should be. PM me if you have any questions in this regard.

 

[Phil Fill]

Most engine are wired/connect to the zinc loop with a fairly big wire. I know my Perkins gen set is. If not and/or you are still concerned you can hang of zinc Grouper with a clip and hang it over the side. I use to have a Grouper zinc, so at most marine stores, connected the bow thruster, until I install a bigger license plate size. The Perkins gen set I ran an additional green wire straight to the big main zincs in the stern, so it should be protected. Might want to check to see if it's connect to the zinc loop?

However, you should still have the exchange check on a regular bases to at least clean ream out for better reaw water flow as junk does build up in the outer side tubes where ther is not much flow. Which reminds me I need to do that this years again.

Also our Perkins gen set engine exhaust is about 6" above the water line and connected to an exhaust hose so when at dock, 99% of the time, there is little/no raw water sitting in the exchange, therefore there is little/no galvoinic action.

 

[RT Firefly]

Greetings,
Gooper zinc?

 

[Phil Fill]

Greetings,
Gooper zinc?

That should be Grouper Anode. I went back and changed.

thanks

 

[RickB]

Most engine are wired/connect to the zinc loop with a fairly big wire. I know my Perkins gen set is. If not and/or you are still concerned you can hang of zinc Grouper with a clip and hang it over the side.

How is that going to protect the internal parts of the engine cooling loop?

 

[RT Firefly]

Greetings,
You're a BAD man Mr. Rick B.

 

[RickB]

Greetings,
You're a BAD man Mr. Rick B.

Just wondering is all ...

 

[Chrisjs]

I agree that zincs should be fitted per the manufacturer's instructions, though I remain confused why some engine require anodes and some do not. While our Cummins and Westerbeke both have zincs, the Yanmar 56HP wing engine has no zincs. It took several phone calls to convince me that there really is no zinc required. Supposedly the engine and its attached Saildrive (SD50) do not require zincs because of some internal Yanmar magic coating or "special" alloys. Beats me!!

 

[healhustler]

That should be Grouper Anode. I went back and changed.

thanks

Phil: I had one of those darned things attached to my rudder arm when I was worried about the condition of my 5" rudder zink (the only one I have). I could never see any signs of deterioration and I was always having to clean the slime off the thing. Several times I left it on while underway. After making sure everything was bonded, I finally threw it to the fishes.

 

[Marin]

We use a zinc on a heavy cable hung about six feet underwater off the side of our boat. The other end is clamped to one of the rudder bars and thus the boat's bonding system in the lazarette.

This is a common and recommended practice in our marina because of the almost constant presence of a thick layer of fresh or brackish water on top of the salt water at the head of the bay. On boats like ours the transom zincs are almost always in this layer of fresh water.

We use old transom zincs on the cable and they go away and stay clean (no slime or algae) just like the zincs on the boat. Makes a great and easy check to make sure conditions in the water and on the boat have not changed. My wife made a big fabric "STOP ZINC" stop sign that we hang on the shifters whenever the zinc is down as a reminder to pull it up before getting underway.

 

[Daddyo]

Lehman 120 has a zink on the heat exchanger.

 

[RT Firefly]

Greetings,
As well as heat exchanger I've got zincs in the oil and transmission coolers as well (Lehman).

 

[JAT]

There are no pencil zincs in exchangers on my Perkins 135's

That's odd.... My 1979 Perkins 6.354's both have pencil zincs in the heat exchangers...and they are 135 NA's...