LML Marine swap

kidturbo

Piston Tester
Jul 21, 2010
2,540
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Somewhere On The Ohio
www.marinemods.us
I believe I seen where somebody said before they had problems on the dyno because they didn't provide a speed sensor input to the ECM.

That was me.. They will run OK without VSS data, but adding a GPS to pulse output converter made my LLY idle and maneuver much better. Dakota Digital unit is what I used. Search my old posts form 2012.

But then GM went and changed how VSS data is received with the LMM. I've been helping get a LMM / A50 combo to run and shift right in a boat for a couple months now. Engine is almost perfect, transmission control is another issue.

Hawk, easiest choice with your harness is finding the factory fuse boxes. Scavenge a couple from the bone yard along with the throttle pedal assembly. Mine used a simple Bussmann fuse/relay box, which can be wired up custom if ya can't find GM pieces.

I'll be down there first of Sept. Was wanting to check out your build anyways. You have my contact.

-Ken
 
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Hawk 40

New member
Oct 30, 2014
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Sarasota
Yeah I need all the help I can get when it comes to the electronics.
I've been in Idaho for most of the summer but will be getting back on it soon and plan to have it in the water this fall. Maybe have things dialed in for the New Year's Day fun run.
 

Kamilmk

Member
Aug 13, 2015
420
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Seymour, CT
Just found this thread with the current post. Getting my popcorn ready for the progress and completion. Subd.

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Hawk 40

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Oct 30, 2014
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Still waiting on the second af cam from SoCal so the machine shop can finish up.
I saw where Wagler is building a pair of 1200 hp marine duramax's for the guys that currently hold the Bermuda Challange endurance record. Going in a custom 50' Skater
 

Hawk 40

New member
Oct 30, 2014
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Thinking about using 10-71 superchargers instead of turbo's.
Would that create any issues with the computer programming?
Any other pros/cons come to mind?
Thanks
 

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
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Minnesota
Thinking about using 10-71 superchargers instead of turbo's.
Would that create any issues with the computer programming?
Any other pros/cons come to mind?
Thanks

With the crank breaking history of the Duramax motor, I don't think it would be a wise choice to drive supercharge's off the front of the crank!
 

Hawk 40

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Oct 30, 2014
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Forgot about the crank issues.
This is a marine app that won't see over 3600 rpm and they have AF cams.
Do you think that's enough lessen the chances of breakage?
It does need to be reliable.
 

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
14
38
Minnesota
Gale Banks probably has the most experience running super chargers on duramax's, but from what I remember he had to have custom made cranks for his race motors running them.

View attachment 39527
 
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WolfLMM

Making Chips
Nov 21, 2006
4,005
26
48
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AL
With good tuning, in a marine load condition, you'll be in boost low in the rpm band.

Are you worried about low end boost?
 

duratothemax

<--- slippery roads
Aug 28, 2006
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Wyoming
In a high-load marine-abuse/duty cycle application, I would be hesitant on running a supercharger and loading the front of the crank like that....JMO

Ben
 

Hawk 40

New member
Oct 30, 2014
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Sarasota
With good tuning, in a marine load condition, you'll be in boost low in the rpm band.

Are you worried about low end boost?

Not really, turbo lag was not too bad on the one heavy duramax boat I've been on. But thought it would be nice to eliminate the hot turbos and simplify the intercooler and exhaust plumbing
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,203
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At Da Beach
I agree with everyone else, dont load the crank anymore with the superchargers. The vvt turbos can build boost almost instantly with the right tuning. Have you looked at what the mainstream marinized duramaxs are running? My buddy sells them if you want some specs...
 

kidturbo

Piston Tester
Jul 21, 2010
2,540
1,378
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Somewhere On The Ohio
www.marinemods.us
Hawk, I finished up work tonight mapping out all the gauge related CAN data off my "exstreamly generous" buddies LMM truck. Now have everything "digital" engine related to make plug-N-play gauges on future marine or specialty swaps. Converting all that GMLAN engine data into NEMA 2k or industrial J1939 protocol as needed.

Think I ended up pulling every major sensor plug on my buddies [perfectly running and driving] 08 truck to capture and scale values from fuel levels, temps, oil pressure, and so on. But the hard parts done, now off to programming a gateway and shooting it out for testing on Dave's boat with a Simrad display in CA.

Note To Self; when scaling rail pressure sensor values using a POTs again, first disconnect the FRP so it doesn't bottom out the slider thus sticking it .. Freaking out your buddy, and causing a sleepless night thinking about 4hrs changing a regulator your stupidity screwed up... Luckily the spring in the FPR pushed the slider back up the bore and out of the sticky zone after setting overnight..
:cussing:

I'll post details on what PIDs and PGN's we can convert to/from in a new thread shortly. For now, get them puppies mounted in that boat. I'm really needing a ride.

Cheers

-K

PS, Andy shot me an image of that Mercuiser seawater pump bracket from my old build that I can recreate in Solidworks. I'll send you the dwg files directly, or can get a pair waterjet cut within a week if you still need them.
 

Hawk 40

New member
Oct 30, 2014
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Sarasota
Thanks, I've got a good window to get things wrapped up now, I don't have to be anywhere but here till April and Will says he can put em in the boat right after thanksgiving.

Can any of you lml guys tell me what this hole/fitting is at the far right of the picture is?
All I remember is that it had a black pipe in it, like a vent return line or something
 

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clrussell

pro-procrastinator
Sep 23, 2013
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Oil drain hole for the turbo if that's the rear valley of the engine.


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clrussell

pro-procrastinator
Sep 23, 2013
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The hole with the paper towels? The hole with the black is the turbo oil drain, not sure on the other hole though.


I didn't see the paper towels... Pretty sure that's coolant for heater hose


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