# Turbo chargers



## Shilo (Mar 31, 2020)

More questions learned folks.
Has anybody run a large 2 stroke with one or both turbo chargers blanked off for any length of time?
Problems encountered, solutions to those problems etc?
Ditto 4 stroke.
Thanks & stay safe, healthy and away from people!


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## makko (Jul 20, 2006)

We had to blank off one of the TCs on a Sulzer 9RD90 due to severe erosion of the casing which led to the cooling water flashing off - It eventually emptied the header tank, which is when we realized the casing was leaking! The only measures to take are to adjust your fuel delivery for less available air and take into consideration the inevitable power reduction. The TC should be removed to avoid overheating.

On a Vee engine (typically 4S), if each TC feeds a unique manifold, you would have to fabricate a Y to feed both banks. Again, adjust fuel delivery for less available air and expect less available power.

BTW, the 9RD90 incident occurred arriving Singapore. A refurbished casing was quickly sourced and delivered by Whaler (quite a sight!). By the time we rebuilt the TC and conducted trials, we had crossed the equator about 27 times! I never got judged in the court of King Neptune, being my first trip, but instantly becoming an old timer!

Rgds.
Dave


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## henry1 (Mar 25, 2015)

In 1984 B&W 55LGF with two BBC T/C's, due O/H on running hours, the 2/E called me, he had cut open the sealed tin with the ball bearing to find it was dirty and wrapped in dirty plastic. Looked in the spares box and found another spare in the bottom of the box. 2/E fitted it with new oil pumps, left port checking operation, after 15 minutes oil was thrashing round, opened cover and oil pump had seized and started spinning so fitted the old one, after 15 minutes same again. Blanked off T/C isolated 1,2 & 3 units and ran on three legs to next port which was Yokohama, home oh IHI called them down. They refused to accept the first spare had been dirty in a sealed tin, the spare we had fitted was original that had a design fault, a key protruded and located in a keyway not visable when inserting the bearing, the new bearings had an annular ring instead of keyway. No damage to the T/C, running time about 36 hours, no problems except reduced revs and lumpy on 3 legs


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## makko (Jul 20, 2006)

Always the bearings, Henry! Lots of people don't realize that the TC rotor only runs on two, generally. It is always good practice to change them whenever the TC is opened up. Lots of TLC and very important to absolutely ensure all the clearances are correct and the safety wire is correctly stringed.
Rgds.
Dave


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## henry1 (Mar 25, 2015)

Agreed I was lucky when an apprentice I was placed with the fitter who allways got the T/C's, the makers men were not allowed to work in the dock but when the BBC guy turned up and saw it was Les doing it he just went off for the day. But this was strange, when I checked the dirty bearing that had come from the sealed tin it had the newer annular ring and there were two older used bearings in the store awaiting sending for recon and checking them they both had signs of not being fully lined up with the key with gouges where they had been forced in place, could see why they changed the design.
Many years later in a casual conversation with a BBC guy he told me about vibration degrading the small quantity of oil in the sump and turning it black because it was being crushed in the damping springs. Not long after this I had this problem and convinced the super to send the rotor ashore to be checked, when we removed it it looked good and I had a night of worry until they called the next morning to say it was out of balance.
Writing this I have remembered many more adventures with T/C's so I will stop and go back to my glass of wine.


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## dannic (Mar 10, 2013)

Shilo said:


> More questions learned folks.
> Has anybody run a large 2 stroke with one or both turbo chargers blanked off for any length of time?
> Problems encountered, solutions to those problems etc?
> Ditto 4 stroke.
> Thanks & stay safe, healthy and away from people!


Was on 10 cylinder 840 bore B&W, 4 pulse turbochargers, they each had shut off flap valve between outlet and manifold so could run with blower shut off if needed. On occassion valve would close by itself and barking of blower woke everyone!!


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## makko (Jul 20, 2006)

I had forgotten that simple check - What colour is the oil! Enjoy your wine! I salute you with a cold Heineken (supposedly working!).


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## Benn (Feb 21, 2008)

Makko,
Had a similar experience when Chief on a RND with erosion of the casing it happened whilst water washing. Luckily we had a spare onboard.
Benn


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