Duramax in powerboat

[GeneralTJI]

I thought the guy in DF figured out what was wrong and it's good to go now?? There was something wrong internally with the motor or something like that? been a while since I read on that thread but I believe there was a reason it was melting pistons so often?

 

[RedHotGMC]

I thought the guy in DF figured out what was wrong and it's good to go now?? There was something wrong internally with the motor or something like that? been a while since I read on that thread but I believe there was a reason it was melting pistons so often?

I thought he said a water port was plugged or something? Last i saw was that he figured it out and its been running a lot better since.

 

[hondarider552]

He hasnt posted much info on what the reason was or as to why, but I believe ditching the oem turbo for a fixed turbo will help. Hell, I remember him saying the only time egt's were under 1000* was through the no wake zone.

 

[baggedLB7]

Pretty sure he found somthing blocking an oil passageway.
As far as oil temps they shouldnt be to hard to keep at bay with running cool lake water through the motor and I dont think that pushing a boat through the water will load the motor as much as say pulling heavy loads up steep grades I may be wrong though.

 

[baggedLB7]

This is what he found and his post from the df.

Definition of Priceless
Hi all, quick update on my cracked piston issues.

Found it...

After having the block bored and hot tanked last summer, we cleaned, inspected, and blew out all the oil passages before assembling the crank and new Mahle pistons into the bottom end. Still contemplating all possible reasons for the recent failures, we carefully inspected each and every part and port. While installing the oil squirter, this small piece of rubber was found in the blocks main oil passage.

Only possible source was the the oil line connecting the remote filter and cooler to the block. Whoever made up these lines [stab type fittings in hydraulic hose] managed to roll the inner hose edge and a slice of it broke free lodging in the blocks primary oil passage. Hence good oil pressure, even with 2 spun rod bearings.

This quarter size piece of debris [missed by everyone at least once] caused; 1 trashed crankshaft, 2 trashed rods, 2 smoked pistons, 3 complete tear downs equaling about $5000 in parts and countless hours of labor and frustration. PRICELESS !!

Moral here, when in doubt, or something just don't smell right, inspect everything, then again and again until you find it. Even if this means drilling and removing all the passage plugs in the block so you can shine a flashlight thru them...

She's good to go now, 30 hours logged since the last rebuild an not a hiccup. Just pulled her out of the garage yesterday, quick oil change and she's ready to smoke up the water again. Here is a short video from a cruise last fall. Will post some WOT runs in a week or two if the river ever clears up.

 

[Chevy1925]

I dont think that pushing a boat through the water will load the motor as much as say pulling heavy loads up steep grades I may be wrong though.

All depends on the prop.

 

[Josh2002cc]

What about the drives? What drive are you going to use?

 

[Jorekore]

What about the drives? What drive are you going to use?

Either SSM 7 diesel 1:1 ratio or an arneson asd6 or 8 depending on hp and torque.

 

[Jorekore]

is it possible to only use 3,4 and 5th gear on the allison trans?
If i use 2 duramax and 2 allison trans will they shift gear at the same time or are all trannies different due to mileage and such?

 

[Kartmnn]

Auto trannys dont work in boats. Guy at the marina tried it with turbo 400s, the props would lose the momentum as it shifted, then the tranny would downshift to recover, this cycle countinues til the trannys blow up.

 

[Jorekore]

Auto trannys dont work in boats. Guy at the marina tried it with turbo 400s, the props would lose the momentum as it shifted, then the tranny would downshift to recover, this cycle countinues til the trannys blow up.

It works! PPE have done it.
http://www.youtube.com/watch?v=Y4ugzTL2y1U
There is also zf 2-speed trannies avilable for boats.

 

[Kartmnn]

In a 21 foot boat that you can push with a 40hp outboard it works. How about something 10000 pounds or more?

 

[THEFERMANATOR]

In a 21 foot boat that you can push with a 40hp outboard it works. How about something 10000 pounds or more?

The ZF 2 speed is designed just for these kinds of apps. If the trans is set up right without a converter it will work. The biggest problem I see with the ALLISON in a large boat would be the parasitic drag that you would have all the time. I imagine you could buy a ZF 2 speed box for about what the ALLISON set-up would cost to hook up that is designed for it. And if it is used in a straight inboard app, I would avoid teh ALLISON as it is not really designed for the thrust load to be applied to the output shaft like you would incur in a straight inboard(unless you went with a jack shaft type set-up with a seperate thrust bearing support).

 

[Josh2002cc]

It works! PPE have done it.
http://www.youtube.com/watch?v=Y4ugzTL2y1U
There is also zf 2-speed trannies avilable for boats.

In a 21 foot boat that you can push with a 40hp outboard it works. How about something 10000 pounds or more?

Thank you.
:truestory:

 

[Kartmnn]

I dont really know what that means. I have no doubt that if you want to spent the money you can make a Dmax push anything. But really a ski boat that weights 2800 and the biggest option motor is a 300hp outboard. What does that prove? That you can fit a $50,000 driveline in a $30,000 boat? That said I am a believer and would love to see this in a Searay 28' not something alittle bigger then my jetski.

 

[adrenaholc1]

If you got the $$$$ then the skies the limit. I could see $100,000 invested to your 1989 vessel to make it cruise good. I've put about 10% of that into my boat to go 10 MPH faster and its been a rough road with a few rebuilds and allot learning the hard way. Boats are harder on engines than anything. Yeah they have unlimited cooling but you would have a plumbers nightmare trying to keep water temps/pressures and oil temps/pressures in they're operating ranges. Running a boat wide open is 100% duty cycle like the back half of a sled pull run everything the engines got is on the table. I'm not saying its impossible and if someone can do it then there's a whole new market for the dmax industry.

 

[Utahski]

It works! PPE have done it.
http://www.youtube.com/watch?v=Y4ugzTL2y1U
There is also zf 2-speed trannies avilable for boats.

Fast diesel boats like yours are using these 2 speeds.

 

[Dan@PPE]

Auto trannys dont work in boats. Guy at the marina tried it with turbo 400s, the props would lose the momentum as it shifted, then the tranny would downshift to recover, this cycle countinues til the trannys blow up.

Are you sure about that? Our's works fine...

[YOUTUBE]Y4ugzTL2y1U[/YOUTUBE]

 

[Utahski]

But really a ski boat that weights 2800 and the biggest option motor is a 300hp outboard. What does that prove? That you can fit a $50,000 driveline in a $30,000 boat? That said I am a believer and would love to see this in a Searay 28' not something alittle bigger then my jetski.

This thread is about Joakim's 50ft boat. But that PPE is boat is very cool......they're in the diesel business and they wanted to do it, so what? Doesn't need to be any more reason than that.

And a 40hp outboard won't do much for a 21ft boat.

 

[McRat]

Just rambling:

I'd rather see steel pistons in a boat application if possible.

It's like towing uphill at full GVWR forever when boating.

I certainly would not turn up the engines in a heavy boat.

A pair of Dmaxes at the factory tune are 600-800HP, detune 25%, and do tricks to relieve temps (big water oil cooler, water intercooler, slightly smaller non-VNT turbo with 2800 redline, water injection.

You need to be able to run them at 100% for extended periods. Getting a hotrod Dmax to survive more than a few minutes at WOT is tough.

But you should get excellent range and economy compared to big blocks.