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How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 18th, 2020, 3:00 pm
by BarryK
Hi all,

I may need to remove the heat exchangers to clean them. I have Crusader 454s with V-drives on a 1990 Santego 3467. The exchangers are under small hatches under the seats in the cabin. It is pretty tight in there. Any suggestions are appreciated.

I will also need to replace spark plugs at some point. How do I get to the outboard ones?

Boat is new to me as of January 2020.

Thanks,
Barry

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 18th, 2020, 4:21 pm
by ColRon
Barry are you sure on that. Since your talking heat exchangers, I assume your crusaders are closed cooling. On the model 350, 454 Crusader they should be mounted on the top rear of the engine near the transmission. That should be your Walter V-Drives under the floor in the cabin. Your raw water intake should pass through them first before going to your pump on the engine.

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 18th, 2020, 8:28 pm
by vineyardgray
I agree with Ron, although there might be another cooler on a closed system to think about - the oil cooler (which on a 454 engine set up is way down underneath the exhaust risers on the outside I.E. closest to the Hull)

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 18th, 2020, 8:56 pm
by waybomb
Crusader.350hp 454 have the oil cooler on the left front of the engine looking at the front.
A "U" shaped device.

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 19th, 2020, 12:49 pm
by BarryK
Yes, the big heat exchangers are under small hatches under the couches. There are also hatches on the floor over the V-drives. I am looking for advice about how to remove the exchangers and disconnect all of the hoses. It is a very tight space to work in. I would at least like to free them up so I can remove the end caps to look for debri.

The U coolers are on the front of the engine. There is plenty of room to work there. I had a recommendation to inspect the inside of the U coolers to look for obstructions.

The reason for all of this investigation is that the port engine puts our excessive exhaust steam over 3000 rpm but the engine temp stays steady at 165 deg. It looks like a steam locomotive. The steaming stops when I throttle back to 3000. The coolant level has been rock steady for a while so I do not think it is an antifreeze (coolant) leak. The engine runs smoothly and it does not use any oil.

The starboard engine temp runs slightly hotter at higher rpm, 170-175 deg. but there is normal minimal steam from the exhaust. Temp returns to low 160s at idle.

I have circulated Rydlyme through both engines using a closed loop with a sump pump to circulate the solution. This did not help with the above issues.

I suspect that the risers and elbows may be getting clogged on the steaming engine. The elbows on that engine are about 10 deg warmer than the other after a 3000 rpm run. I checked elbow temps with an IR thermometer gun when back to idle for a few minutes. 108 port, 98 starboard. The difference may be greater when actually running at speed. Former owner claims that the elbows and risers were replaced about 2 years ago but he did not produce receipts for the work. They look pretty new and paint is clean and intact.

The raw water pumps were recently professionally rebuilt including new bearings and impellers. Belts are new and tight.

The only thing I have not yet done on the steaming engine is to replace the hose from the V drive to the raw water pump intake. It looks OK but hard to inspect under the engine. I replaced the starboard side since it was collapsed (metal spring was corroded) and it was restricting intake flow.

I have not changed the spark plugs yet. I dread trying to get to the outboard sides of the engines, very tight spots. I'm looking for advice here as well.

Thanks!
Barry

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 19th, 2020, 6:04 pm
by waybomb
The first place the impeller pieces get stuck is those oil coolers, and blocks flow.

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 19th, 2020, 8:31 pm
by BarryK
Yes, that is what they told me on MarineEngine.com. I will be sure to carefully clean them out, and replace if necessary.

Thanks,
Barry

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 19th, 2020, 9:08 pm
by ColRon
Barry,

It sounds like the 3467 is more different from the 3867 than I realized. From you description of where the heat exchanger is, it sounds like your engine room is larger than the cockpit alone is and extends back into the cabin. On my 3867, the entire engine and transmission is accessed directly from the cockpit. I even have enough room to put my 250lb self between the outboard side of the engine and the hull, it’s the inboard side that harder to access due to the mounting of the genset between the engines. It’s amazing what effect 5’ in length and 2’ in beam can make. Since the two are so similar in design, I naturally assumed you could access everything the same way.

Do you check your transmission fluid through the same access hatch under the seat?

Re: How to remove heat exchangers, spark plugs on Santego 3467?

Posted: August 22nd, 2020, 11:39 am
by BarryK
Yes, the transmission dipstick in just forward of the heat exchanger, same hatch. I'll take some pictures today.

The engines are mounted about 2 or 3 feet apart. This makes maneuvering the boat to dock pretty easy. There is a lot of prop walk in reverse and you can push the stern to port or starboard pretty well.

Barry