Cleaning your heat exchanger procedure

[knotflying]

Hi all,

Roam and Illusions have been buddy boating and we were at a point where periodic maintenance was upon us and we figured why not do it while we are laying over for a week.
One of the PM items was to clean the heat exchanger. Roam had never done his and the boat was 7 years old in Salt water and fresh water environment. Illusions is coming on 3 years in an all salt water environment. Roam had also noticed that his engine temp was climbing somewhat, which is an indicator of some blockage. Prior to doing Roam's flush we were able to remove the end cap on his transmission cooler, which is the first entry of sea water. Low and behold we found an accumulation of sea grass and cleared that out. The cooling veins did have some build up. We did a test ride to see if there was improvement prior to the flush and there was, but we thought it could be better so we then proceeded with the heat exchanger cleaning on both engines. The results were improved and the cleaning effects obvious when looking at some of the components afterwards. Below is a detailed list of each task required to complete the procedure. It took about 8 hours start to finish and cleanup for Illusions. This was related to the difficulty associated with the Impeller removal and that is twice!!! I also replaced the serpentine belt as well. Roam was about a 4 hour process and again that is because of the ease of impeller access.
So here is the procedure. Enjoy!

Mike Rizzo

Ranger Tug Heat Exchanger Cleaning Procedure For Yanmar 110 or 4BY2

Materials List

Small wooden plugs
3 Feet 3/4” Hose (or Other Size as required for the Input side of the
Raw Water Washdown Pump)
3 feet 3/4” hose (or other size and reducers as required to connect output side of the raw water washdown pump to the input side of the raw water cooling system)
3 feet of hose to connect to the exit side of the raw water system by
the mixing elbow
Hose Clamps
Two 3 gallon Buckets
1 – 1.5 gallons Rydlyme

Procedure:

Close Raw Water Seacock

Remove Impeller
Replace Impeller Cover without the Impeller

Remove the engine zincs and replace the caps

Disconnect and plug the water input to the stuffing box. On the 4BY2 disconnect hose from mixing elbow and plug. On the 110 disconnect the hose at the stuffing box and plug both the hose and the nipple on the stuffing box.

Remove Raw Water Washdown outlet and Inlet Hoses
Connect and Clamp 3 foot hose to input side of Raw Water Washdown Pump and connect hose from Outlet Side of Raw Water Washdown to Input side of Cooling System

For a Yanmar 110 HP use a reducer for the 3 foot ¾” output hose and a short length of 1” hose to connect the output from the raw water washdown pump to the input of the transmission oil cooler

For 4BY2 connect the output side of the raw water washdown to the sea strainer. This can be accomplished by just switching the hose from the sea strainer feeding the raw water pump to the output side at the raw water pump.

Remove the heat exchanger outlet water hose from the exhaust mixing elbow water input.
Connect a 3 foot hose from the heat exchanger outlet to a bucket

For the Yanmar 110 use a 3 foot 1” hose.

For the Yanmar 4BY2 use a 1.25” to ¾' reducer and a ¾ threaded to a 3/4” barbed fitting connected to a 3' 3/4” hose

Fill the Bucket with two gallons of fresh water
Use the pump to flush the system twice, replacing the water between flushes.

Fill the bucket with one to 1.5 gallons of Rydlyme (biodegradable)
Circulate the Rydlyme for two hours intermittently using the pump Dispose of the Rydlyme

Flush the system with fresh water and two buckets twice or until water exiting is clear.

Now would be a fine time to inspect and clean your mixing elbow.

Reconnect all the hoses as originally installed.
Replace the impeller.

Replace the engine zincs

Open the seacock.

Start the engine and check for leaks.

 

[j&lgray]

Mike & Rich;

Nice job on providing this level of detail. Now, can you do one for the Ranger 29 owners and their Yanmar 260 engine? You can catch up to Andiamo in Georgia.

You guys are really good!

 

[knotflying]

Hi John,

Glad all is well on Andiamo. There will be plenty to see from Savannah to the Chesapeake so take your time on this section and enjoy the scenery and history of our country.
As far as the heat exchanger goes I am fairly confident that the procedure will be the same for the 6BY as the 4BY. You may need a little more Rydlyme, but you will need to buy 2 gallons anyway so you should be golden. By the way, I submerged my mixing elbow in the RydLyme after doing a wire brush cleaning and it came out very clean after the wash. If you decide to do a side trip up the Long Island sound when in the New York area give me a shout and if schedules permit we can do a cleaning then.

Mike Rizzo

 

[HRowland]

Nice description. Are you planning to do this on the AC/Heat Pump also?

Howard

 

[trailertrawlerkismet]

Mike thanks for posting the detailed heat exchanger cleaning procedure you and Rich experienced, I've saved it for future reference. Question, how did you find the inside of your exchanger maybe as a comparison to Rich's and did the completed process make a difference in your engine temp's?

 

[knotflying]

On the 4BY2 engine it is very difficult to remove an end cover an inspect. There was some build up in the exhaust elbow, so one would assume there was some in the heat exchanger as well. Probably a bore scope would have given me some type of visual. The interior impeller housing was pristine when the process was complete. I figured since I was changing my impeller anyway and it was three years I may as well do it. I hear several different suggestions regarding the time required to clean the exchanger anywhere from 1 year to 5 years, so I figured three was a good number. I definitely did not want to wait until I started seeing rising temperatures. I have not done a run since the cleaning so I cannot report if there is a degree change in cooling. My temperatures seemed to be in range, 195 at low RPM's of around 2,000 and 202 at WOT.
By the way Jim, supposedly you should descale the Air conditioner on a regular basis as well. Another procedure will most likely be posted in the future.

Mike Rizzo