De-tuning a turbo DD 6V92

[Dswizzler]

Can anyone explain the down side to de-tuning a single turbo pair of 6v92s on a 58ft 60000 lb trawler ? I'm not in any hurry and would rather be able to cruise all day long at 6-10 knots. I know I'll need to reduce my props and change fuel injectors, but I need to change props and rebuild one motor already, so is there any real down side ?
Other then perhaps get out of the way of a storm..?

DSWIZZLER

-- Edited by Dswizzler on Wednesday 20th of October 2010 10:45:27 PM

 

[FF]

The DD book will have the allowable range of injectors you can install to bring down the power , but it may nor save the cost of the new injectors.

DD, esp turboed engines must operate at about 60% power and over to have efficiency.

Sounds like you are looking for 50 hp from 350 hp engines, which will not be efficient if you down rate them to say 300 hp.

Either different engines or a different boat , or man up , make huge wakes and enjoy 1MPG .

I would operate at 1100rpm or at 1lb of boost as a minimum to ensure engine longevity.

 

[Doc]

6-92's getting 1MPG! FF, what have you been smoking?***

 

[FF]

6-92's getting 1MPG! FF, what have you been smoking?

Well I assumed he was at hi idle.

 

[sunchaser]

Just shut down one engine as another post on this site has been laboring over*and over, and over -----. Or cut back to 8.5 knots and once per day goose it up 1500 rpm for about 15 minutes to blow it out.

 

[Jim Spence]

I get 1 1/4 to 1 1/2 mpg @ 1100 rpm on my 435hp 6-92 TAs. Speed is 9.4mph.

 

[FF]

IF the LWL were 49 ,(doubtful) your best (in terms of cheap) would be 8K or under.

Can you pull it back even more? And maintain oil pressure?


-- Edited by FF on Sunday 24th of October 2010 11:51:40 AM

 

[Jim Spence]

8 knots is 9.2 mph. So at 9.4 I am right in the ball park.

 

[FF]

MPH? MPH! , mariners don use no stinking MPH!

 

[Jim Spence]

Since we travel the AICW a lot and all the charts are marked in statute miles it makes more sense to do calculations in miles. Gallons per hour is another pretty meaningless measure on the ICW when one minute your going with the tide then you cross an inlet and now it's against you. Then you get to a manatee zone that is Idle Speed, then they are working on a bridge it is slow speed minimum wake!