25 bhm w/210b cummins

reeg75

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I own a 25' bhm with 210b cummins. My question is that i run at 2,000 rpms and cruise at 11 knots is this normal or should i be going faster? Boat is not loaded down.
 

BillD

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I own a 25' bhm with 210b cummins. My question is that i run at 2,000 rpms and cruise at 11 knots is this normal or should i be going faster? Boat is not loaded down.

Do have a couple pictures of the engine placement in the hull?
Fuel tank placement ??

What does the engine have for a gear ratio and what size prop and pitch is the engine turning ??
 

lobstercatcher

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I own a 25' bhm with 210b cummins. My question is that i run at 2,000 rpms and cruise at 11 knots is this normal or should i be going faster? Boat is not loaded down.

Sounds like you should be running faster.

What is the engine RPM rated at, gear ratio and wheel?

I think my 35 duffy is faster with 200hp.
 

BillD

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I cruise my 210 at 2150 to 2200.

If a 210 6BT is propped to 2600 (has to be accurate) with the boat as heavy as one will use it then a 2400 rpm cruise will not "hurt the motor".

Prop it to 2700 rpm (accurate) and you can cruise the motor @ 2500 rpm.

200 off the top of rated rpm (2600)(must be accurate rpms) is acceptable.
 

reeg75

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bill d. the engine placement is midship. 1.5 shaft, fuel tank is mounted on the stern and it turns 20 inch wheel. When i have her at 2,200 rpms i get a noise like when you open a back window in a car? any info will help
 

BillD

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bill d. the engine placement is midship. 1.5 shaft, fuel tank is mounted on the stern and it turns 20 inch wheel. When i have her at 2,200 rpms i get a noise like when you open a back window in a car? any info will help

Hmmmm ? :confused:

The noise ?

Do you mean like an "airhorn" sound? Something like that ??

Hard for me to assess what you mean by a "car window opening" ??

You can check the silicone/rubber hose and clamp connections between the turbo and the intake manifold.

What you "could be" hearing is an air leak as the turbo begins to spool up and generates pressure.
 
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25 BHM

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25 bhm

I have the set up 2000RPMs around 11kts I run around 2250-2350 and I get 14-16kts wot is 22 what are you running for gear and prop ?
 

DIRTY RIGGERS

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Obviously check that noise that you said you are hearing. I don't know how you can hear anything over that cummins though. They are some noisy buggers. I'd check the air cleaner to make sure it is clean and has a good seal. Also I'd check all of the hose clamps on your compressor side and make sure the hoses are not ate up from age or from who knows what. After those run her up carefully to see if you eliminated that sound of air you heard. If she hits the 2850rpms which is the fuel stop with no load then you are in good shape. I'd run that motor in your boat at 2350 without batting an eye. That's a good speed you are getting in that rpm range.

I have a pair of 210's in my boat and I have run that engine at 2350 which is the recommended cruise rpm for over 10 hrs at a time on long runs without stopping. The cummins like to run in the 75-90% range and as long as you have a solid engine alarm setup and the engine is propped to 2750ish at fuel stop then the engine will be happy for years like that. My engines are original from 1989 never having been rebuilt. Only routine maintenance when needed. I used to run my boat at 1900 rpms all the time at 16-17kts and I thought I was just saving the engines from working too hard. Well turns out that I was getting an excessive carbon build up from not running hard enough and that lead to my turbos lagging and not spooling up as fast as they should. This also affected my injectors. Couple of yrs ago I had the injectors rebuilt and turbos serviced and started running harder as per advice from my injector shop. My engines run better than ever and don't smoke at all at idle anymore.

The cummins 210 is nothing short of amazing. It can take a serious beating and doesn't get much simpler to work on. You got a gem on your hands!!!
 
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mako239

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on my 28 bhm w a 210 cummins and dry exausht/keel kooler i do about 10.8-11 knots at 2000 rpms
 

Toolate

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I think he means a harmonic vibrating sound. SOunds like the whole boat is vibrating. Maybe something is bent?
 

reeg75

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25' bhm

Thanks everyone for the input. That noise is not there at 2000 rpms but when i bring her up to 2200 rpms it bellows right through you don't know if the wheelhouse is amplify the noise. what could be bent?
 

Toolate

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I know what you mean when you said the sound is like when the back window is open in a car. Its a harmonic vibration that occurs at a specific speed but it really is always there and just amplifies itself at whatever speed due to the shape/volume of the car interior.

I was just suggesting that you may have some kind of harmonic vibration from a bent prop or shaft or something or maybe not enough prop clearance at the tips (just going from what I have read here). I guess to me it sounds like a vibration caused by some moving part, not an engine issue. Keep in mind that I havent heard it...:rolleyes:
 

sandytows

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If a 210 6BT is propped to 2600 (has to be accurate) with the boat as heavy as one will use it then a 2400 rpm cruise will not "hurt the motor".

Prop it to 2700 rpm (accurate) and you can cruise the motor @ 2500 rpm.

200 off the top of rated rpm (2600)(must be accurate rpms) is acceptable.

I have heard this before, but it makes me skeptical.
my 6bt210 runs 2600WOT and I cruise at 2200 I would not be comfortable running above 2200 for extended periods. 6300hours and going strong.
 

steveinak

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If a 210 6BT is propped to 2600 (has to be accurate) with the boat as heavy as one will use it then a 2400 rpm cruise will not "hurt the motor".

Prop it to 2700 rpm (accurate) and you can cruise the motor @ 2500 rpm.

200 off the top of rated rpm (2600)(must be accurate rpms) is acceptable.

In my opinion running any engine 200 under WOT is only running it right to the rebuild shop in a short time. This is coming from a guy that had 11,000 hours on one of those junk volvo duoprop outdrives it was hooked up to 2 different engines.
 

BillD

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In my opinion running any engine 200 under WOT is only running it right to the rebuild shop in a short time. This is coming from a guy that had 11,000 hours on one of those junk volvo duoprop outdrives it was hooked up to 2 different engines.

Steve,

I'd actually run a 6BT @ 2500 when conditions permit.:eek:

At 2500 rpm the engine will be burning 9.5-10 gph...well within the factory "life expectancy" of the engine.:D

My annual running hours...125-150.

I'm 60 yrs. old, any diesel engine I run will be running STRONG long after I'm GONE !:D

FWIW, Bill D
 

GLA

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Thanks everyone for the input. That noise is not there at 2000 rpms but when i bring her up to 2200 rpms it bellows right through you don't know if the wheelhouse is amplify the noise. what could be bent?

try opening a deck hatch the next time your out cruising. it could be a matter of air coming into the engine causing a noise. like a back window open in a 4 door truck or car.
 

BillD

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I have heard this before, but it makes me skeptical.
my 6bt210 runs 2600WOT and I cruise at 2200 I would not be comfortable running above 2200 for extended periods. 6300hours and going strong.

No biggee, run 2400 with the 210 if you want or have to !!:D
The rpms won't hurt the engine or dramatically shorten its life.
It's all about total gallons burned over the life of the engine and preventing any "mishaps" that will kill or shoten or prematurely shorten the life like an "over heat", running the engine "over loaded' (btw make sure your 6BT can reach max rpms of minimum 2700) etc.

Loss of raw water alarm and an extra high temp coolant switch are mandatory IMO.


Think of the 6BT 210 as a de-rated 6BTA 370 kinda like putting a "cork" under the peddle of the 370 and limiting the rpms to 2500.;)

All this is just MHO.
Run the engine as your see fit and are comfortable with.

Bill D
 
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steveinak

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Its always hit me kind of funny when talking with sportfishing folks about engine longevity that the SF guys stick out their chest and say "yeah their great engines i got 2000 hours out of it before a rebuild" and when talking with the commercial guys you hear "i got 6000 hours on that engine and she still running strong". When i started in the gillnet biz here in AK the engine of choice was the volvo 41 w/duoprops, to my amazement they were only getting 2500-3000 hours out of those engines, when i asked on how to run the one in my bowpicker they told me "they like to run 200 under WOT" well that didn't fly with me i ran it 5-600 under and i got 6000 hours out of that engine, repowered with the same and when i sold the boat(3 years ago) that engine had 5200 hours and to my surprise its still running, sold the boat to a russian kid and they are totally numb/dumb about engines & run the shit out of them. By they way my outdrive had 11,000 hours(was on both engines) on it when i sold that boat.
 
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