tackling the water heater on my 9.2A

[bugbitten]

Spent a couple of hours at the boat today. I got the fresh water pump back together (with properly positioned water heater barbs and a new temp sender for an analog gauge) and reinstalled with new gaskets and true Yanmar hoses, using decent AWAB clamps. I didn't have time to work on the heat exchanger, or the exhaust. The new exhaust elbow looks almost as pretty as the new mixer elbow. The small elbows that connect the back of the heat exchanger to the mixing elbow definitely need some serious cleaning before they go back in. They look like they need to borrow some of my Simvastatin. Again, it's a good thing I decided to tackle this.

I ran a bunch more fresh water through the block to thoroughly flush it before putting in the new Havoline ELC. I do need to turn the thermostat on that new water heater down. I nearly scalded myself!

Have dug up a load of fittings I'd assembled some time ago with the hope of installing an analog oil pressure gauge without disabling the alarm.

John

 

[woodster]

that's great john doing this work is better for you and me if we don't try to do it all in one day ...gives us time to think about what we need and what we have done...sort of like eating an elephant ...one bite at a time

 

[bugbitten]

Here's a bit of an update on this project.

Yesterday I finally had everything on the Yanmar back in place and fired it up. Despite the engine block being at 45 degrees, it not having been started in two months, and the batteries being pretty weak, it fired up reasonably quickly. I noticed immediately greater raw water flow coming out the exhaust. Of course, it could well be wishful thinking, but it seemed like twice the water was exiting than I used to see. Given how small an opening was left for the expended raw water on the old mixing elbow, my estimate probably isn't unreasonable.

With the water temp at 48 degrees, the engine took some time to come up to operating temperature. During the wait, I kept adding fresh ELC and water. I had a section of transparent tubing where the coolant returned to the FWP housing from the water heater, so I could see when it started flowing and when all the air was out. All the new hoses and gaskets on the front of the engine held nicely, but there was some leakage at the union between the mixing and exhaust elbows. The new, aluminum mixing elbow's threads are a bit iffy, so the connector was not threaded in as far as it should've been. I've pulled that and ordered a stainless steel one to swap the aluminum elbow with. I'll get the threads chased at the machine shop at some point and keep it as a spare.

Right now, I'm using the original 1.5" water lift muffler. I was looking at the 2" Centeks and came across their sizing chart, which says they don't recommend diesels over 10 HP be used with the 1.5" muffler. Mine, as stated earlier, is rated at 16 HP.

The engine did begin to warm the very cold water in the water heater, but I'll probably have to actually have the boat out and the engine working under more of a load to get much heat transfer in this sort of weather.

I'm about to order new 3/4" hose for the raw water line, and a bronze Groco strainer to add to it. There was one small shell lodged inside the heat exchanger, so this should keep that from happening in the future.

John

 

[Capt jgw]

I had the same trouble with the WH in my Columbia 8.7 a few years back. The heater sat just inside the starboard cockpit locker. The tank came out fine after removing the jacket, but I wasn't about to disassemble the brand new one to put it in. Had to trim the fiberglass edge of the lid coaming about 1 1/2" to get clearance.

 

[woodster]

Here's a bit of an update on this project.



With the water temp at 48 degrees, the engine took some time to come up to operating temperature. During the wait, I kept adding fresh ELC and water.





John

John you may want to read the container on your ELC and make sure you have full strength...mine is 50/50 and says not to add water ....congrats on getting it back up and running

 

[bugbitten]

Thanks, Woody. I just went and checked and it says "concentrated," so I should be good. Somewhere buried in the parts/tools pyramid I have a Robinair refractometer. I'll dig it out and check the coolant mix to make sure I'm in good shape. I keep the boat heated, so it's usually not critical, but...

John