44 ft Endurance Diesel
12-30-2013, 12:36 PM
#101
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Love to see all these new Diesel Projects popping up..
Took me a while to understand what Joe's been preaching also, but he's spot on when it comes to the prop speed being key. HP is the easy part with the diesels, but just because they say you can turn them 4k doesn't mean your gonna do it all day long. Diesels work off of heat and compression, the harder ya run the more heat they will build.
My built Duramax can run safely at 2600R's for hours, but push it to 3600R's and the heat builds quick, and that time drops to a couple minutes before the gauges start peaking. Best every day example of a hot diesel boat setup is pulling that same boat up an endless hill with your diesel truck. Push the throttle down for an uphill mile and watch your gauges. That's a diesel boat every day run...
Thinking of starting another double Dmax build, and a 2-speed "overdrive" trans is the FIRST part that will be fit to each engine. 3500R's at the prop while turning 2500R's at the crank is my ultimate performance goal.
Nice Build.
-K
PS. Did 120 miles running on Cumberland and Dale Hollow couple weeks ago on just 24gal of fuel. 5mpg..
Took me a while to understand what Joe's been preaching also, but he's spot on when it comes to the prop speed being key. HP is the easy part with the diesels, but just because they say you can turn them 4k doesn't mean your gonna do it all day long. Diesels work off of heat and compression, the harder ya run the more heat they will build.
My built Duramax can run safely at 2600R's for hours, but push it to 3600R's and the heat builds quick, and that time drops to a couple minutes before the gauges start peaking. Best every day example of a hot diesel boat setup is pulling that same boat up an endless hill with your diesel truck. Push the throttle down for an uphill mile and watch your gauges. That's a diesel boat every day run...
Thinking of starting another double Dmax build, and a 2-speed "overdrive" trans is the FIRST part that will be fit to each engine. 3500R's at the prop while turning 2500R's at the crank is my ultimate performance goal.
Nice Build.
-K
PS. Did 120 miles running on Cumberland and Dale Hollow couple weeks ago on just 24gal of fuel. 5mpg..
12-30-2013, 12:58 PM
#102
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My engines don't do that I can run them wide open continuously (approx 3950 rpm) and they don't continue to increase in temp, they run close to 1200 degrees EGT and about 170 degrees water temp wide open, longest I have done it has been about 20 min. Normal cruise (45mph 3300-3400 rpm) is 950 EGT and 160 water temp. I am planning on putting the water injection system back in to control the EGT's better when i am running it hard, just to be on the safe side 1200 degrees is pushing it.
FPT say you can go up to 1400 EGT. Great engines!
12-30-2013, 01:33 PM
#103
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Have you found anybody that can modify the FPT for more power? That is the reason I am also considering the Cummins there are hundreds of aftermarket products available to increase the performance.
12-30-2013, 01:41 PM
#104
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I am planning on the FPT or Cummins for my next boat, good to hear! Yanmar says keep it below 1200 and you can run forever so that is what I will do.
Have you found anybody that can modify the FPT for more power? That is the reason I am also considering the Cummins there are hundreds of aftermarket products available to increase the performance.
Have you found anybody that can modify the FPT for more power? That is the reason I am also considering the Cummins there are hundreds of aftermarket products available to increase the performance.
12-30-2013, 02:31 PM
#105
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If you increase power on the 560 FPT ,there is an increase in EGT off course ,if money is no issue ,you may consider a slightly bigger compressor ,just to move more air to lower the EGT,s , you may also consider a cut back to the turbine wheel ,or let a reputable turbo /tuner determine how many degrees the wheel already is ,it might be already done at the factory ,if not ,it can also be a improvement in back press and lower EGT
12-30-2013, 03:05 PM
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Stirling. Been looking at another turbo as an option.And/or a larger intercooler.
The gearboxes(300ATS) limits the search a bit as they are on the limit already.
The solution is to flatten the torquecurve and that means some hours on the dyno.
Plus its a lot of work to get the engines out... Maybe next year...
The gearboxes(300ATS) limits the search a bit as they are on the limit already.
The solution is to flatten the torquecurve and that means some hours on the dyno.
Plus its a lot of work to get the engines out... Maybe next year...
Last edited by 7075T6; 12-30-2013 at 03:11 PM.
12-30-2013, 04:16 PM
#107
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EGT's are easily lowered with some water injection, I am planning on using X-power drives so I can eliminate the gearbox from the list of things that can fail, but that also limits how much power the engines can make, I think I can max out around 700 and still have the drives live. But if the boat does over 70 with stock motors I may leave them alone, if it does 78 I'll have to mess with them to get over 80. 
12-30-2013, 04:26 PM
#108
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The lower the exhuast backpressure the lower the EGT. A diesel is just like a gas engine there is really no difference when it comes to air flow and how the engine will react to it.
Lower the boost, increase the flow that lowers intake temperature and allows the aftercooler to work better and remember Pressure is inversely proportional to Flow and Flow is affected by:
Tube diameter - If the diameter of the tube is halved the flow through it reduces to onesixteenth.
That means that flow is directly proportional to d4.
Length - If the length is doubled the flow is halved, therefore flow is inversely
proportional to the length of the tube. (A central line is much longer
than a cannula, and for the same diameter air flows more slowly).
So larger pipes cut on a bais will always flow more with less pressure than smaller pipes cut straight with higher pressure.
Lower the boost, increase the flow that lowers intake temperature and allows the aftercooler to work better and remember Pressure is inversely proportional to Flow and Flow is affected by:
Tube diameter - If the diameter of the tube is halved the flow through it reduces to onesixteenth.
That means that flow is directly proportional to d4.
Length - If the length is doubled the flow is halved, therefore flow is inversely
proportional to the length of the tube. (A central line is much longer
than a cannula, and for the same diameter air flows more slowly).
So larger pipes cut on a bais will always flow more with less pressure than smaller pipes cut straight with higher pressure.
)What if port engine fails when out on the water?
