CAT 32 Aftercooler removal and test..why?

Cat had an issue on the original C32 aftercooler design and came up with a redesign. I ve been running a 2009 84 Lazzara with C32s for almost 4 years now. I found the boat for the owners and the first thing my local cat guy mentioned when I asked him to survey the engines was that the AC would have to be upgraded. We did it after closing the deal (about $16k per engine) and haven’t touched them since. That was over 1500 hours ago.

it seems to me that your local dealer is looking additional business.

before the current boat I was running a boat with 3412Es. Put 4000 hours on her in 8 years, I think we cleaned the ACs once

I was aware of the 6 year replacement recommendation but not testing every two years. Sound a bit extreme... hard to believe Cat can’t make aftercoolers (not intercooler BTW) last more than 6 years...

A lot of Cat owners are questioning the maintenance schedule. My manual for 3406E and C15 engines updated 4/15/2015 states aftercooler clean and test at 15,000 gallons, or 1,000 service hours, or 2 years calendar time. Replace every 6000hrs or 6 years. Not sure if the same as the C32. I question this because of what you stated, low hours over the 2 year clean and test period. Average time for recreational use is way less than 1000hrs. in 2 years. Was told by a Cat mechanic the warranty program was the reason for the schedule. Adds a lot of expense when you amortize cost for cleaning and replacement over 6 years. You need to check for updates on your Cat maintenance schedule, it maybe different than original.

I find a lot of engine shops, all brands not just Cat, will get into a routine of recommending bundling services together that may not exactly match each engines requirements. The most common I've heard is a 2yr/1000 hr service that cleans and/or replaces everything that salt water runs through. Getting the service manual and reading it along with having good notes on past service is a good way to stay on top. Often times mechanics are dealing with customers who are very behind on service and they do indeed need everything done at once to catch up.
It's a hard job to go to the owner and lay this out. I remember one time getting out all the books and having them turned to the maintenance pages as I was making notes. The owner asked what I was up to and then we started looking at it all together. Our discussions went smoother once he started to realized the scope and requirements of keeping a boat in good condition.
I also remember getting a major service done on generators while we were in Mallorca. The invoice was staggering. A replacement generic plastic coolant overflow tank was over $150 (after converting from euros). In the US I could have bought it for under $10 at the auto parts store.

If your aftercoolers are original, have them pulled and CHANGE them with new ones. CAT recommends changing them every 6 years. I've seen them fail, once even on a 3 year old yacht with the new style C32 aftercoolers and causing a rebuild. I don't think I'd inspect/pressure test them every 2 years, I WOULD just pull them every 6 years and replace them with new ones.

Who ever told anybody C32s were cheap. Even when dust collecting.

I would never let salt water in any engine,genny , again. I would use a interstage heat exchanger . I been thinking how to incorporate a Stainless steel hull bottom also to reject all the heat . IMO The only salt water running into the boat is for the water maker or too interstate heat exchangers.

Keel coolers?

You would need more surface area than that. Essentially the entire bottom of the boat. I'm thinking 50 to 90 foot luxury planning boats with high horsepower engines, duel generators, and enough AC cooling capacity to keep your ice cubes from melting on the hottest day.
While I believe retro fitting is possible, every one would be a one off build to match the total btu load. It would be much better to be fitted into new hulls already sized correctly for the btu load of production boats.

Interstage heat exchangers are another option.

Sucking in Salt water and pumping it through a engine then out is the KISS way.

Refrigerants are another possible solution as they absorb heat , move it , then reject it easily.

not my experience. In 3 years and 8 months, and 1700hours, besides oil changes this is the extent of our costs

port engine ECU replacement $3900
Raw water system descale $400
2 impellers $1000
Valve cover seals stbd $200
IAP sensors $400
Remove clean and seal ZF coolers $1200

I ll go over further needs this fall with the Cat tech, we ll do another set of impellers (I do them every two years /1000 hours or so) and are what else may be needed

not bad for 10 year sold 1650 HP engines. I can tell you that we spent at least twice as much keeping the Cruisair chiller system going...

Using it too little is as bad if not worse than using it too much. At 83 hours per year it would be cheaper to charter.

That's all well and good if you're interested in an 8 knot boat. Most people aren't and a keel cooled system will not work on a yacht or sportfish.

Are they, practically?
If you are aware of any pleasure boat built with that setup, I'd be very curious to have a look at her specs.
I'm always interested to learn something totally new - to me, anyway.