Wind Horse now has 5700+ hours on her two little John Deere diesels, over 50,000 nautical miles of cruising the oceans. If you have looked at “experienced” exhaust systems, you will know that an exhaust this clean after almost 6000 hours is the exception rather than the rule.
The first photo is one of the flex couplings between the engine exhaust manifold and the exhaust dry riser.
This is the exhaust manifold elbow for the port engine. The probe sticking into the elbow is the exhaust gas temperature pyrometer.
Finally, the starboard engine’s exhaust manifold elbow. These elbows typically see the most most carbon build up, and in order to operate this cleanly:
- Engines must be run with sufficient load to burn fuel efficiently.
- They must not be overloaded.
- Back pressure has to be within correct limits.
- Inlet air volume must be sufficient.
It is all part of having a quiet, efficient, ocean going yacht, with a long, happy life.
Cory McMahon and crew replaced the motor mounts today, and made a few changes in the engine room as an experiment to reduce noise. We shall do a sea trial tomorrow and report the result.
Posted by Steve Dashew (October 31, 2011)
November 1st, 2011 at 4:31 pm
Having been in the exhaust system of several tractors (including adding a turbo to an engine used at high altitude / 9000+ ft density altitude) I can say those are beautiful pictures. What is your target cruise and max. EGT and how far down stream from your turbine is the temp. sensor?
November 1st, 2011 at 7:53 pm
Hi Daryl:
The pyrometer probe is about a foot from t he t urbo. Normal EGT runs about 700F in calm and maybe 725F in headwinds, at 11 knots, and 1850/1900 RPM. MAx EGT at wide open throttle is 875/900F.
November 1st, 2011 at 4:33 pm
I’m curious as to what prompts the engine mount change? Do you think 5,700 hours and seven years a typical life for engine mounts or is there another reason for the change?
November 1st, 2011 at 7:57 pm
Hi Jim:
The aft port mount on both engines was sagging about 1/4″ (6mm), and at 5700 hours we thought a change was in order. Might have gotten away with just the low mounts (which re upsized one notch), but the conservative thing to do was all of them. The engines are a bit smoother running now, although they were pretty good before. The other six were exchanged for the same ratings as before.
November 2nd, 2011 at 6:13 pm
How did you settle on your current engine mfg? Not the engine size but the engine brand.
Thanks
John
November 2nd, 2011 at 9:11 pm
Hi John:
There were several factors in choosing Deere. First, the very flat torque curve was ideal for our needs. Next, the engines had a very positive reputation with commercial users for power and gensets. Third, the were easy to work on. Provisions for adding auxiliary drives and large alternators were excellent. Finally, service and pars were available world wide.