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Nut for anode on heat exchanger on bottom? 1990 454's CID (FWC)

N

nightstalker

Regular Contributor
The manual given to me by the previous owner shows the nut for the sacrificial anode for the heat exchanger on the top of the exchanger. I was looking to check out the sacrificial anode today and only saw two nuts on the bottom of the heat exchanger. One, about 3/4 of an inch across, I believe is the one for the anode. The other, about 1/4 inch across, I have no idea what it's for. I didn't remove either one. Why would the anode be on the bottom, considering the fact that I'll lose all the antifreeze in the tank when I unscrew it? I guess I'll have to catch the antifreeze when I remove the nut. Anyone else have the nut on the bottom?
Nightstalker
 
THere should be two small pipe plugs on the HE, one for the raw water side, one for the coolant side. There is also the larger one for the anode, as you correctly surmised. THe anode plug is towards the end of the HE, in the raw water path.
 
diver_dave said:
THere should be two small pipe plugs on the HE, one for the raw water side, one for the coolant side. There is also the larger one for the anode, as you correctly surmised. THe anode plug is towards the end of the HE, in the raw water path.
Click to expand...
The smaller ones are drains? Is it odd that the anode plug is on the bottom of the HE?
Thanks,
Nightstalker
 
no, if you ever have the endcap removed, you'll see the anode right around where the raw water hose connects. It's probably there so it's always "wet".

Not that much comes out when you change the anode, a small bucket will catch it and the you can do the swap.

Bob
 
The pencil anode is not on the anti-freeze section on the HE so you will not loose any anti-freeze. Some raw water will come out, so either catch it with a small pail or rinse the area below later with fresh water. I recommend removing the end cap so you can see if there are any old pieces of zinc in that cavity and you can also view the cooling tubes to see it they may need to be cleaned. I remove both end caps and rod out the tubes if needed.
 
bobct said:
no, if you ever have the endcap removed, you'll see the anode right around where the raw water hose connects. It's probably there so it's always "wet".
Not that much comes out when you change the anode, a small bucket will catch it and the you can do the swap.
Bob
Click to expand...
I'm not familiar with your H/E, but that sure sounds correct to me!

Just a suggestion or two:
When you purchase replacement pencil anodes, purchase a hand full of them.
Most people are not changing these as often as they should.
If we have them on hand, we're more likely to replace more often.
Sometimes these systems can go through two/three in one season.

You can buy one or two complete pencil anodes, and a bunch of replacement anode pencils.
The catch is...... I've seen a different thread size/pitch from one brand pencil to another.
(the brass TP threads are always OK.... it't the pencil threads that vary.)

This is why I'd suggest buying a hand full of pencil anodes while at it.

.
 
All great responses....I'll add that it is not unusual for a subcontracted part to have subtle modifications over time. These are due to a multitude of reasons. What I'm getting at is that little differences are likely to happen (especially when using owner's manual pictures - they should be marked for guidance only). Specifics include physical location of the pencil zinc's fitting (as long as it is in the raw water side it can be effective) and the existance of a raw water drain plug (you don't need if if you pull the end cap).... the philosophy behind these "product improvements" and its further discussion would be best captured in a dedicated thread.
 
Since we're all here tossing in thoughts...here's mine: Our anodes are located about the 2 o' clock position in the top portion of the HE as viewed from the closest end cap. While I am using the specified parts in all areas of the engine, this is one spot where I have YET to remove the brass cap and the zinc is stuck in the hole. On occasion, I have had to drift it into the HE and then remove the cap to extract the old zinc.

It is not an uncommon event for these two locations. How frequently do you think the rubber "gasket" can survive removal and replacement cycles? I still change them every year or 2 depending on those cycles
 
Regarding the end plates and rubber gaskets:
1... if you phase or index them the same each time....., keeping them on the original end...., they'll usually survive several R&R's.
2... if the end plates become distorted (i.e., loose some of the "cup", then the plates many not cause a good rubber gasket seal around the perimenter of the main H/E shell.

I think that if we keep those two things in mind, we can reuse these without any issues.
Replacing them, of course, is never a bad idea! :D

Just my two cents on that!

.
 
Good thread, now I have a question. I would think it is time to remove the end caps on my HE's. 1989 7.4's, I have the OEM log style manifolds and risers and I was told that these manifolds restrict removing the screws in the end caps, is this true. I have a special long handled brush I purchased some months ago for this job. I was also concerned about the gaskets, but now I know if I am careful in removing these, I should be able to reuse them this time.
 
I gotta say that I have replaced both my end caps (4) and their rubber gaskets for less than $65.00 in total. The new end caps are 3/16 thick bronze and the 3/32 rubber discs seem like they will last for a very long time. I really do think I will not need to change the end caps for another 10 or more years...they are extreme solid parts. Go find some new ones
 
Thanks, but perhaps I did not ask clearly. I tend to do this as my mind is faster than my fingers typing.

The question is about the ability to get the end caps off when having the log style manifolds. I was told that I can not and have to remove the manifolds to get the HE end caps off. I find it difficult to believe they (Crusader) would design it like that. If I can simply remove them with out taking off the manifolds, then I can clean them. The engines are FWC 1989 7.4's with the OEM manifolds.
 
I have 1989 454s in a 1990 Silverton 34C -- straight drives -- with rear mounted exchangers. There is nothing in the way that prevents the easy removal of both end caps and also always rodding out the tubes. Now if someone is telling you that you have to remove the manifolds, have you even looked to see if that is true?

Erich
 
The bolt holding my end caps one is only 3/4" long so if you have that much clearance, you should be fine. Even if you are brushing out the core you can use a wire handled brush and still just flex it in . As Erich mentions, look and see what clearances you have. From experience, don't try to use a small caliber rifle cleaning kit, the cleaning tip will break off and get stuck
 
3/4 inch will work, I have somewhere around 3 inches. It goes to show not to listen to every person with an opinion, this guy was supposed to be a expert that told me the log style manifolds would have to be removed the clean the HE.

The HE is rear mounted and the risers and hoses connect to T's just behind and in the rear of the HE. I flushed the HE with muriatic acid last year and thought rodding out the HE should be done. I may do it this tomorrow or the next day. My dock is behind my house so it is easy to work on it.

Thanks to everyone for your help.
 
Hallandale ....When I was a kid we used to go fishing on Sunny Isles Fishing Pier. I don't know where that is but I seem to remember that name. It was 1961 and I was in 4th or 5th grade.

You will be fine with those HE end caps
 
Yes, Hallandale. This was a best and most affordable waterfront property, not on a canal but a lagoon. I just moved here from Delray Beach about 4 months ago. Love the property and having the boat a few steps from my back deck is very convenient.

Thanks for the advice, as soon as the "honey do's are complete, I can get back to the boat projects.
 
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