Vroooooom!!!

Our good old perkins is running even better with it’s new exhaust system. The installation went through without any real problems. I did have to borrow a bicycle from Anthyllide in order to get to the Ace Hardware to buy one last hose adapter.

Here is a picture of the new hot exhaust riser before it was insulated.

20130108-195247.jpg

The system now runs without any leaks, and the engine is starting easier and running smoother!

20130108-200241.jpg

We are very excited to be mobile again and are looking forward to motoring down the Intracoastal Waterway while keeping a close eye on the engine to make sure there are no surprises.

Out with the Old, In with the New

When we began the process of building a new exhaust system. One piece that had to go was our muffler. Here it is welded out of stainless steel.

20121217-175528.jpg

After reading up on how the exhaust should be installed, all the experts agreed that after water was injected into the exhaust line it should run downhill all the way into the muffler. That makes the elbow on top of this muffler a real problem. It is on the inlet to the muffler, so the exhaust gases have to push the injected water uphill at least a little bit. In addition the welds were starting to rust on the bottom of the muffler, possibly leaking a little bit of salt water. We decided to replace the muffler with one better suited to our boat.

After speaking with Centek about the correct muffler for our engine we had a plan. We were going to replace our metal muffler with a fireproof, rust proof, fiberglass muffler. In addition we could get a muffler that had the inlet on the side, making it easier to mount the muffler below the water injection point. Just before calling Centek back to place the order I contacted Defender to see what their price was for a similar muffler. They had the exact same muffler listed for a much lower price. Unfortunately they didn’t have it in stock, but they could have Centek ship it directly to me…I don’t quite understand the pricing, but I’m happy to keep the extra dollars!

Here is the new muffler safely installed in the engine room.

20121217-180331.jpg

Now all we had to do was come up with something to do with the old muffler. We came up with a lot of ideas, but we’re starting to think this muffler-like object isn’t really good for anything anymore.

We tried using it as a dumbbell to keep us in shape since we’ve been anchored for so long.

20121217-180723.jpg

We tried using it as an anchor for the dinghy…

20121217-180801.jpg

We tried using it as a watering can for our new thyme plant..

20121217-180841.jpg

We tried using it as a teakettle…

20121217-180922.jpg

We tried using it as a new musical instrument, very tubalike but without any pleasing sounds.

20121217-181029.jpg

We had it try out for “The Wizard of OZ” but they found a better tin-man…

20121217-181128.jpg

However our muffler was most successful as an internet billboard to deliver this message!

20121217-181233.jpg

Engine Update

This blog post gives a summary of what was ACTUALLY wrong with our engine leading up to this point. It conveniently compresses two weeks of troubleshooting down into one post. If only I had read this post before starting the process…

When we suspected that our raw water pump was leaking into the engine the first step was to disconnect the pump from the engine so that no more water would get in. I continued to monitor the engine oil level even though we weren’t running the engine while waiting for the new pump. Even with raw water pump separated from the engine our oil level continued to rise! This meant that we must be getting water in through our exhaust system. As soon as I disconnected the exhaust hose leading to our muffler I found our “smoking gun”. I had finally found the real problem. The exhaust hose was full of water and it was at a level high enough to be running into our exhaust.

The short version of this problem is that the exhaust system was installed improperly, and has been allowing saltwater into our engine for a long time.

The long version is that three things were wrong at the same time which allowed water to backfill into the engine.
1. There was no anti-siphon loop on the water injection into the exhaust. This should have been installed with the engine.
2. The water lift muffler was mounted higher than the exhaust outlet. This is supposed to be at least a foot lower.
3. Our raw water pump was allowing a trickle of water to leak by when the engine was off.
The combination of these three items allowed the water into our engine.

This video shows these parts of our engine.

Once the problem was located we took steps to fix the situation. All of our resources indicated that with this much water coming in through the exhaust our engine should be at a high risk of “hydrolock”. Hydrolock is when one or more cylinders inside the engine are filled with water and since the water can’t be compressed the engine can’t turn over. Not wanting to do any damage to the engine trying to start it. I disconnected the exhaust system from the engine, and flushed the oil system. I moved the oil through the engine by turning the engine over by hand using a large wrench. After cleaning the lubrication system thoroughly we refilled the engine oil including a dose of Marvel Mystery Oil an oil additive designed to help clean the engine. I reconnected the muffler at a level lower than the engine exhaust and ran the engine long enough to get it up to temperature and drive out any residual moisture. The engine started much easier and ran smoothly!

An Endeavor 37 here in St. Mary’s also has a Perkins 4.108 and we went over and listened to his engine to make sure ours wasn’t make any highly unusual noises. The owner Josh was nice enough to start his engine up for us and let us listen at a variety of RPM’s. Josh’s engine was just as loud as ours, and sounded nearly the same!

After I setup a proper exhaust system our engine will be running better than ever. Hopefully having saltwater in the system hasn’t added too much wear to the engine.