Sea Trials / Very Brief Black Smoke

[GJD]

Went to sea trials yesterday on our potential 53 MY. Cold start yielded an expected and 'pretty' brief white plume fom the P exhaust. SB side however gave same except just as much of a black plume (still very brief then all clear). Boat had sat on the hard for about 4 weeks. Both engines started right up. Clark Diesel of Cincinnati's specialist said NP and that his visual inspection of pistons (viewing panel) showed about half useful life left (1500 out of 3000 hrs). Oil test coming back withn 48 hrs. About 700 hrs SMOH.

Any thoughts re the black smoke?

Thanks very much

Greg

 

[Nonchalant1]

Black smoke (not blue) is incomplete combustion, usually caused by hard acceleration where the RPMs can't keep up with the fuel being supplied. I'd say that if it cleared up right away and had been on the hard for a month, don't worry about it. How did they perform underway?

Doug

 

[GJD]

Engines performed beautifully. Ran smooth and cool. More survey specifics to come tomorrow. Thanks for your input Doug. Looks like we're sizing up nicely.

 

[krush]

How does he determine useful life left? Does he look at the cross hatching or the rings?

 

[GJD]

His assumption is a 3000 hr useful life per engine.

His comments state "Found no broken rings or scored liners. Found at least 50% of wear groove was missing. When cold start engine performed well / compression very good. Under load speeds were 2210 SB and 2265 P. Coolant stayed below 190. Exhaust smoke was clean. Oil pressures OK. Crankcase pressure OK. Took 5 oil samples."

 

[Finalee]

Ditto on the black smoke. What engines are they?

 

[GJD]

DD 6V92TA's x 465 hp

 

[Finalee]

Finalee has the same motors. They have been great so far. Plenty of power to plane a 43 DC.

 

[GJD]

All oil tests favorable. Report states 'no corrective action required'.

This is great news.