Twins with Twins, Anyone?

kidturbo

Piston Tester
Jul 20, 2010
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Somewhere On The Ohio
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It won't be cheap that's for sure. Just the cranks, rods, and pistons equals more than I sold my whole LLY Dmax boat for.. But to have someone come to ya and say "build it right and do it up how you see fit" is a great honor. Only requirement, she be faster than it was with the BBC gassers... That means 105+
 

kidturbo

Piston Tester
Jul 20, 2010
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Somewhere On The Ohio
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What you think about LML block, Callies, Howards, and Fingers rotating assemblies ,LMM heads, 12mm pump, and twin 64mm's side by side feeding them at 4000 R's.

Goal is run DSP5 setups like I had on my boat, but with 600-1100 range settings. What ever they make, they gotta make it all day wide open for at least 1000hrs. I just haven't seen anyone brave enough, or with a dyno capable, ever pin them down at 1300hp and head off to the movies... 900 has always been where I feel comfortable they will survive. Beyond that, I'd have to see someone with a capable engine dyno just drop the hammer and walk away before I try it..

:thumb:
 

kidturbo

Piston Tester
Jul 20, 2010
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Jeremy hasn't dropped the hammer and went to lunch yet..

I know that boat well, who you think gave them the idea? LOL. She's still long way from being wet. That owner expects 1200 all day long. While I know those engines made well over that for about 5 seconds, I'll be impressed when I see them do 5hrs straight.

To date my old LLY still holds the Dmax boat record with 300+ hrs at 675+hp and still together. Believe it or not, even that power level is much much harder than it sounds.

:)
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
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At Da Beach
Jeremy hasn't dropped the hammer and went to lunch yet..

I know that boat well, who you think gave them the idea? LOL. She's still long way from being wet. That owner expects 1200 all day long. While I know those engines made well over that for about 5 seconds, I'll be impressed when I see them do 5hrs straight.

To date my old LLY still holds the Dmax boat record with 300+ hrs at 675+hp and still together. Believe it or not, even that power level is much much harder than it sounds.

:)
Cool project, most people don't understand the rigors of marine use. We put our equipment thru hell, it takes soon much more to make it right in a boat versus a car or truck. Good luck with it buddy...:)
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
13,378
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Mid Michigan
What you think about LML block, Callies, Howards, and Fingers rotating assemblies ,LMM heads, 12mm pump, and twin 64mm's side by side feeding them at 4000 R's.

Goal is run DSP5 setups like I had on my boat, but with 600-1100 range settings. What ever they make, they gotta make it all day wide open for at least 1000hrs. I just haven't seen anyone brave enough, or with a dyno capable, ever pin them down at 1300hp and head off to the movies... 900 has always been where I feel comfortable they will survive. Beyond that, I'd have to see someone with a capable engine dyno just drop the hammer and walk away before I try it..

:thumb:
From reading your past threads, I realize you're probably the guy who will find a way to make it work, but based off what Dmaxes have been put thru in the past, I just dont see how one (let alone two) can hold at that power level for that long a duration even when built with the best parts money can buy now. You're looking at a lot of cubic dollars on a lot of very expensive custom parts to give yourself even a chance to make it work.
We're just not there yet in terms of reliability at the very extremes of high perf. Hope your customer realizes that...
 

Awenta

Active member
Sep 28, 2014
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CT
Let me know where you threw those big blocks out! I'll go clean up.

Hate to say it but a built Cummins platform may be more reliable.

It's going to need some serious cooling that's for damn sure.

Sent from my SM-N910V using Tapatalk
 

malibu795

misspeelleerr
Apr 28, 2007
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in the buckeye state
Jeremy hasn't dropped the hammer and went to lunch yet..

I know that boat well, who you think gave them the idea? LOL. She's still long way from being wet. That owner expects 1200 all day long. While I know those engines made well over that for about 5 seconds, I'll be impressed when I see them do 5hrs straight.

To date my old LLY still holds the Dmax boat record with 300+ hrs at 675+hp and still together. Believe it or not, even that power level is much much harder than it sounds.

:)
Cool idk that!!!

While I don't have wot experience at in hours I got it in minutes.... with towing... I have has sustained 3/4 throttle for hours, heavy high winds drag
oil temps are biggest issue I see, as it goes nuts faster then any other temp .

Most engine dynos don't have cooling capacity for themselves and the engine for all day long.. unless you access to major OEM dynos

IDK if Wagler deck plate dmax is capable of full water cooled or not. Definitely something I'd look at hard it it was..

I'd be looking at fordged crankshaft. Common 1000hp+ build up with Wagler heads. No one really know for definitely if the AF cams are a fix either....
Gale banks went and increase main journal size on his crankshafts, in short increased material in the area that brakes.. are there for sale to the public ???? IDK couldn't hurt to ask. He's usually pretty active with the public on FB
 

CaptPhil

New member
Sep 10, 2011
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Delaware
oil Temps will be easy to control, unlimited access to cold water helps.

egts will be the biggest hurdle to overcome.

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SmokeShow

Active member
Nov 30, 2006
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Lawrenceburg, KY
What's considered a comfortable "load" to be on an engine for an extended time? No engine is made for 100% load 100% of the time, that would be grossly over built or overworked wouldn't it?

Next question then is how to make desired hp at said sufficient/safe/normal loading, right? The lower on the load curve the engine can be ran and still make sufficient power, the better chance of this working out with a pair of duramaxes, right? Or am I off in la-la land?
 

04LB7yz

New member
Aug 16, 2013
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Way North Minnesota
2 speed tranny would almost have to be a necessity in order to run a big enough pitch prop to run those speeds and still have it be dock-able. The nice thing is with the #6's you can get down to or below a 1:1 gear ratio vs a bravo setup at 1.34:1.
 

kidturbo

Piston Tester
Jul 20, 2010
1,240
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Somewhere On The Ohio
www.marinemods.us
From reading your past threads, I realize you're probably the guy who will find a way to make it work, but based off what Dmaxes have been put thru in the past, I just dont see how one (let alone two) can hold at that power level for that long a duration even when built with the best parts money can buy now. You're looking at a lot of cubic dollars on a lot of very expensive custom parts to give yourself even a chance to make it work.
We're just not there yet in terms of reliability at the very extremes of high perf. Hope your customer realizes that...
I've had a hard time keeping his expectations realistic. But he understands why you don't see any big HP diesel boats running 400ci. We started out at 800hp, and he was soon talking about 1200. Which I quickly explained is not an option, unless you plan to build 4 more for spares.

I pegged the stock rod LLY with nothing but set of cast Mahle pistons for about 15 minutes straight one day right after the rebuild. Seated the rings right now.. lol. Then added those 10 WOT 1-mile runs on biodiesel for Guinness. After that I felt comfortable they will hold upwards of 700hp with EGT's around 1600. But even that low power range keeps your ears and eyes pealed for anything out of the ordinary.

All the oiling, water, and charge cooling issues are pretty well sorted out by now. I'm still questioning that Banks intake capacity, love the design but compared to what I've ran before, it's small. Biggest concern remains the cranks. Jeremy has 2 Callies on order for me after my friend snapped his new LMM up around 700hp. He's since put Guy on a stroker build for his boat. So watch for more on that one.

My best odds approach to the cranks is internal balance the Callies and slap a heavy azz flywheel on them. That's the only other rotating mod my LLY had besides the pistons, and you could feel the difference. Do everything possible to dampen the vibrations out of them.

As for the big Cummins marine options, I inspected the internals of a rock solid 700hp marine version couple month back. They run Monotherm pistons for starters. I spoke with Fingers a bit about the options, or lack there of, and we feel the cast Mahle is still second best option for longevity right now. Just gonna oil the crap out of them...

-K
 

kidturbo

Piston Tester
Jul 20, 2010
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That has to be one of the only Baja's out there with SSM #6's...

If the guy wants fast... He should be using a different hull...
Yes that is the only one I know of with 6's factory. And those are being replaced with Weismann WMD's. It's been spinning 16.5dia 31pitch 4 blades and ran 100+ with that setup. I have a pair of Tyson Garvin's [owner of the other big Dmax project boat] two speed transmissions coming for it. They are 1.5 first and 1.0 second gear. Electronic shift and rated at 2000ft lbs torque.

One thing for certain, the hull will be the weakest link now.. :spit:
 

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