Replacing Engine Zincs
 

My boat is equipped with twin 3116 Caterpillar diesels. It is a 1995 model.

I am hauling it out for bottom paint in two weeks. They will replace all of
the external zincs as part of the paint job. While it's out, I would like
to replace all of the zincs on the engines as well. This is not included in
the paint job, so I would like to do it myself. The problem is that my
manual is very vague about where they all are. It says that I should have 8
zincs per engine and has a picture of 2 of them. I can find those 2. I
still can't locate the other 6 though.

Short of hiring another mechanic to replace them and watching him, (Which
isn't out of the question) what is the best way to find the other zincs and
is there a way to know the sizes of all of them before I go to work so that
I can go buy new ones ahead of time?

Any advice would be greatly appreciated!

I do not have a 3116 but have had many others over time... best
advice....Follow the salt water..... .

Start with the through hull.... (probably no zincs there...)
Go to the water pump. Look around for a brass screw that does not have
original Cat paint on it. That should be the zinc. It should go next
to some type of air, fuel and or transmission cooler. These items may
have zincs as well. It will probably go next to the heat exchanger...
this will have at least one zinc. From there it probably goes to the
exhaust elbow.... probably not one there.

That should do it.. remember.. the only reason for a zinc is to save the
metal from electrolysis from salt water so all the zincs will be in the
sal****er path.

BTW.... if you get the nut and not an old zinc... you may have to go
zinc hunting by removing end caps or hoses. Not hard but a bit of a
pain to get them out. One lost zinc is not bad but a 10 year old boat
will probably have a few in there that need to be removed.

Also a few more tricks....
-replace them all every 6 months or sooner... any more and you will lose
them. (they tend to corrode more towards the nut)
-buy one or two full sets of zincs with nuts... buy LOTS of pencils
only... replace the old ones with the pencils at 1/4 the price of the
whole assembly.
-Always replace the zincs even if they look near perfect. zincs are
cheap, removing 1/2 zincs from the flow is a pain.
-I always PAINT the first 1/2 inch (no more) of a pencil zinc nearest
the nut with an oil based spray or brush paint. This helps the zinc
from corroding at the nut and makes it easier to get out after 6 months

have fun!!!



Gary wrote:
My boat is equipped with twin 3116 Caterpillar diesels. It is a 1995 model.

I am hauling it out for bottom paint in two weeks. They will replace all of
the external zincs as part of the paint job. While it's out, I would like
to replace all of the zincs on the engines as well. This is not included in
the paint job, so I would like to do it myself. The problem is that my
manual is very vague about where they all are. It says that I should have 8
zincs per engine and has a picture of 2 of them. I can find those 2. I
still can't locate the other 6 though.

Short of hiring another mechanic to replace them and watching him, (Which
isn't out of the question) what is the best way to find the other zincs and
is there a way to know the sizes of all of them before I go to work so that
I can go buy new ones ahead of time?

Any advice would be greatly appreciated!

On Sat, 19 Feb 2005 17:40:48 GMT, "Gary"
wrote:

My boat is equipped with twin 3116 Caterpillar diesels. It is a 1995 model.

I had triple 3316s in my Hatteras, darn good engines.

I'm not familiar with the 3316s. Mine are 3116s. I am very happy with them
though. I'm still kinda puzzled about those darned zincs though. I'm
really disappointed with my engine manual. If they could take the time to
include a picture of 2 of the zincs, I wish they'd have done the same for
the other 6. I'll eventually find them, but I wish that there was a source
for a picture or diagram etc of the locations of them.


"Harry Krause" wrote in message
...
On Sat, 19 Feb 2005 17:40:48 GMT, "Gary"
wrote:

My boat is equipped with twin 3116 Caterpillar diesels. It is a 1995
model.

I had triple 3316s in my Hatteras, darn good engines.

Gary wrote:
I'm not familiar with the 3316s. Mine are 3116s. I am very happy
with them
though. I'm still kinda puzzled about those darned zincs though.
I'm
really disappointed with my engine manual. If they could take the
time to
include a picture of 2 of the zincs, I wish they'd have done the same
for
the other 6. I'll eventually find them, but I wish that there was a
source
for a picture or diagram etc of the locations of them.


"Harry Krause" wrote in message
...
On Sat, 19 Feb 2005 17:40:48 GMT, "Gary"
wrote:

My boat is equipped with twin 3116 Caterpillar diesels. It is a
1995
model.

I had triple 3316s in my Hatteras, darn good engines.



Gary, chect your transmission cooler, engine oil cooler, heat exchanger
(probably has two zincs), inter-coller and exhaust riser.

By the way, contact your local Cat dealer, they give one day classes to
owners on a regular basis. The classes are engine specific, and are
supposed to be very hands on, so you should be able to pick up quite a
bit. And the cost is very reasonable. What their really trying to do is
get you to buy parts from them. I'm going to a class next month for my
3208's, cost like $30, can't beat that. By the way, you should be able
to purchase the zincs at a local marine supply store. But the zinc's
you buy won't fit the Cat caps, so you have to buy the cap and zinc. I
replaced all my zincs for like $50, I have the non-Cat caps. I visited
my Cat dealer, they asked me if I had the Cat caps, if I did all I
would have to do was by the zinc itself. I didn't have the Cat caps,
they wanted $700 for all new caps and zincs for the two engines. I told
them where to go, and bought the ones from the marine store. At that
price, I can replace them plenty of times.

WOW! I had no idea about the zinc prices and caps etc. I'll DEFINITELY
look into that ASAP!

I'm not sure of a local Cat dealer, but I'll research that as well and check
on the classes. I can use all the help I can get.

Thanks!

Gary


"Capt John" wrote in message
oups.com...

Gary wrote:
I'm not familiar with the 3316s. Mine are 3116s. I am very happy
with them
though. I'm still kinda puzzled about those darned zincs though.
I'm
really disappointed with my engine manual. If they could take the
time to
include a picture of 2 of the zincs, I wish they'd have done the same
for
the other 6. I'll eventually find them, but I wish that there was a
source
for a picture or diagram etc of the locations of them.


"Harry Krause" wrote in message
...
On Sat, 19 Feb 2005 17:40:48 GMT, "Gary"
wrote:

My boat is equipped with twin 3116 Caterpillar diesels. It is a
1995
model.

I had triple 3316s in my Hatteras, darn good engines.



Gary, chect your transmission cooler, engine oil cooler, heat exchanger
(probably has two zincs), inter-coller and exhaust riser.

By the way, contact your local Cat dealer, they give one day classes to
owners on a regular basis. The classes are engine specific, and are
supposed to be very hands on, so you should be able to pick up quite a
bit. And the cost is very reasonable. What their really trying to do is
get you to buy parts from them. I'm going to a class next month for my
3208's, cost like $30, can't beat that. By the way, you should be able
to purchase the zincs at a local marine supply store. But the zinc's
you buy won't fit the Cat caps, so you have to buy the cap and zinc. I
replaced all my zincs for like $50, I have the non-Cat caps. I visited
my Cat dealer, they asked me if I had the Cat caps, if I did all I
would have to do was by the zinc itself. I didn't have the Cat caps,
they wanted $700 for all new caps and zincs for the two engines. I told
them where to go, and bought the ones from the marine store. At that
price, I can replace them plenty of times.