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Anyone know the zinc size for heat exchanger and u cooler on 454

R

rmm

Regular Contributor
Can't remember what size t

Can't remember what size the zincs are for the heat exchangers nd u-cooler on 1988 454. Anyone know? Trying to order just the zincs without the plug. Think I need diameter of plug and or zinc diameter and length.

Thanks
 
"I saw something simple but in

"I saw something simple but interesting at the boat show. There's a company (I have the name somewhere if you guys want it), that make their
zincs with a thin steel rod in the middle of the casting.

That keep the zinc intact as it wears down instead of breaking off in chunks.

Bob"
 
"RM, I've found an issue w

"RM, I've found an issue with ordering just the pencil anode! The anode attachment threads!
Not all use the same thread (depends on where and who manufactures them)
The 1/8", 1/4" and 3/8" NPT brass portion will be consistant..... it's the actual anode threads that can very.
I've found this to be true and with the same supplier..... different times of the year/different inventory source!

Point being..... I've found it best to order the entire anode (brass and pencil) ..... and while doing so, order a extra pencil anodes.

."
 
"Bob,
I would like to know wh

"Bob,
I would like to know what vendor that is...
I like the idea. I will need to see if its in the cost effective range of the Scottish.

PS When start the flush out next month, what do I use to be sure I am getting all the old zinc out of the u-coolers? Or does that require a removel?

I did some searches on site and am missing the hit on the proceedure. I did see some acid flush posts but none mentioned old zincs hang around...

Thanks,
Scott"
 
"Scott,

I used a 50/50 muri

"Scott,

I used a 50/50 muriatic acid mix. I did it differently as I was on a mission to see how and why the problem exists. IF it all went south, I would need a new one anyway.

After de-soldering then tops of of the u-coolers, we plugged the hole for the zinc and filled both sides with the mix. Did it twice til the reaction stopped then flushed with water...re soldered, re painted and re used..That was June 2008."
 
"Scott,

The company is perf

"Scott,

The company is performancemetals.com. The pencil zinc is called "SecureCore". It looks like they have a pretty good selection of sizes but don't know the pricing.

Lighthouse Marine must carry their line, I picked up the brochure at their booth.

Bob"
 
"The wire sounds like a nice i

"The wire sounds like a nice improvement but I doubt it will eliminate the problem.

On the threads, I've never experienced the mixed sizes, at least on the E-0 pencils. Have always ordered the camp brand and from multiple sources. 1/4"x20 if I remember correctly.

Scott: Removal and disassembly is the only way I know of to ensure complete removal. If you have access to a borescope, that is another alternative. My experience is that the 'parts' will stay loose or get embedded in the tubes on the 'engine' side of the cooler, right at the opening. I'd also think that the acid bath approach would produce good results if starting from an unknown state."
 
"I talked to Bob about the thr

"I talked to Bob about the thread issues and he said that CMP Gloabal is all he will use and they make the threaded part of zinc longer and that makes the screwing in tighter/harder... but less likely to fall out. The brass plugs that they sell will match the zincs all year.

Mark,
You dont mean de-soldering them like Al did?
I think its best for me to do something good to them since I have forgotten about the zincs for 3 years!

We are running the right temps now and want to keep it that way."
 
I think 20-30 minutes in an ac

I think 20-30 minutes in an acid bath will likely get rid of most anything in the water passages. probably with 95% certainty. The only way you can be sure it is 100% clean is to look at the passage tubes.....how else you gonna do it?
 
"I did 2 acid baths, about 5-1

"I did 2 acid baths, about 5-10 minutes each time. without taking them off the engine. You could see the bits of zinc flush into the bucket as they were fizzling like crazy.

I didnt trust my soldering skills...."
 
It was recommended to me by a

It was recommended to me by a couple mechanics to not even use zincs in the U coolers because they are the reason the coolers become blocked! Besides you can get a new U cooler for $200 nowadays from a company in Bellingham. Two less zincs to worry about now.
 
""It was recommended to me

""It was recommended to me by a couple mechanics to not even use zincs in the U coolers because they are the reason the coolers become blocked!"

I believe that to be true, but proceed with caution. The reason for zincs in these copper containing coolers is to prevent copper corrosion, and ultimately, leaks. A leak in the transmission side is bad, and WILL cause you to leak out ATF when running and ingest seawater (if in the ocean) during cooldown. A lack of ATF WILL cause clutch pack damage. Seawater WILL cause internal bearing wear and rust. I can also tell you this can happen in a short timespan, like a weekend. Just this thing happened to me last season.
A leak in the engine side, while I have not experienced that, could be even more destructive.
If you choose to run without zinc in seawater, I'd, at minimum, flush the raw water side out after each use, and replace the cooler every 10 years. Others seem to have good luck replacing the zinc before it falls apart."
 
"One more comment on U cooler

"One more comment on U cooler zincs. The cooler forces high velocity raw water past the zinc. From the 3 coolers I've taken apart, the zincs erode, even before they flake apart. The clogs I see look like dried mud, eventually blocking the majority of the copper tubes. I've seen engines labor with 15 of the 21 tubes blocked with this "dried zinc mud". This residue will not backflush away with water, either you attack it with acid or you unsweat the bottom cap and mechanically remove the residue."
 
"These are actually called &#3

"These are actually called "sacrificial anodes", and for that very reason of Self Sacrificing, rather than the material that they are trying to protect!
And remember.... they are only "Zincs" if the anode material is "Zinc". (Aluminum and Magnesium is also used.... but you'll not hear the term "Mags" or "Als" used. LOL)

But back on topic.... If a mechanic is suggesting that we/you forgo an anode, I'd say that he may need a refresher on the topic of galvanic corrosion!!!!!

A more reasonable suggestion would be that the anode be replaced <u>more frequently</u>.... not omitted!"
 
"Right on Ricardo! I have an

"Right on Ricardo! I have an aluminum cruiser in fresh water, so I use a blend of magnesium, zinc and aluminum anodes. In fresh water mag would be way to active.

Jeff

PS: For those of you who doubt the need for anodes, look carefully at the below photo.

375990.jpg
"
 
"Highly doubt that any amount

"Highly doubt that any amount of anode protection would have saved that outboard in the duration that is must have spent unattended..... but I certainly agree on the importance of anode protection.
Wow, that's nasty!"
 
"I experienced the ATF saltwat

"I experienced the ATF saltwater intrusion problem after 19 years of changing zincs. After replacing the ATF fluid and the U-cooler, it works fine. So I will not change U-cooler zincs anymore because it is a waste of time and money IMHO. Obviously I still change my genset and engine heat exchanger zincs."
 
"Al Felker:

If you got 19 y

"Al Felker:

If you got 19 years with the zincs, what are you expecting without them?

I'm curious as I switched HX to the mercrusier parts when the factory one failed internally. I was a bit shocked when I found the new HX have no zinc pencils. After repeated inquires, the regional service rep called, stating they weren't needed as the mounting system isolates the HX from the block (electrically). The HX's have provided over 15 years of service and are still leak free. The way the older OEM oil cooler mounts, electrical isolation is tough..."
 
""After repeated inquires,

""After repeated inquires, the regional service rep called, stating they weren't needed as the mounting system isolates the HX from the block (electrically). The HX's have provided over 15 years of service and are still leak free. "

MM: that's encouraging. How is isolation achieved? rubber bushings, plastic bracket or ?"
 
For those who think that an in

For those who think that an inline heat exchanger/oil cooler is isolated due to being connected to rubber suction hoses (each end) may not be considering the conductivity of the sea water itself. The very sea water that is part of the electrolyte that creates the galvanic action!
 
"Dave:

They have two semi-c

"Dave:

They have two semi-circle mounts that bolt to the back of the heads. The HX sits in the semi-circles, maybe 3-4" in from the endcaps. Before setting the HX, they have an adhesive lined rubber strip that goes between them. A large hose clamp retains the HX to the mounts.

Since the initial install, I've added more sheet rubber to go under the rest of the clamps (and replaced the original). more for cosmetic reasons than anything else.

I can't say I've ever measure the impedance between the HX and the block. They run their oil coolers in a similar manner - no zincs - and usually mount them in those vinyl coated clamps."
 
"3 years with a 1991 boat and

"3 years with a 1991 boat and no real service record. Makes you want to pick up a couple ucoolers...

Mark, doernt the salt water and fluid make connection?"
 
"Scott; I'd not want to r

"Scott; I'd not want to run on 19 y/o coolers in the salt.
For either galvanic corrosion or electrolysis to occur, there must be an electrical current. If you look at just the cooler as an isolated object, there are still dissimilar metals involved, namely copper, lead/tin (solder), and maybe others. In the cooler these metals are already bonded together, by the fact that it's all brazed together. Add in a conductive electrolyte, namely seawater, now you could have a closed system of electrical current that could cause metal erosion. Enter zinc, that metal will have a higher electrical reactivity, so it suffers the mass reduction. With no sacrificial metal, then I suspect you need to take more care with the dissimilar metal situation and maybe use more nickle/copper alloys that are less reactive.
If, you further bond the cooler to yet other systems, like the engine, you put even more metal in the equation. It sounds like Mercury Marine supports the isolation strategy. You will hear similar arguments regarding underwater fittings, like seacocks as well. My boat is bonded, but I see advantages going the other way as well."
 
"All I can say is the Merc Cre

"All I can say is the Merc Crew isn't perfect but they do pretty good overall. I'd say they are near the top when it comes to understanding corrosion. Lots of individuals like to pick on them but when you look at the number of products out there, their numbers aren't bad at all."
 
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