DIY - Duramax Marinisation
03-23-2016, 09:51 PM
#21
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Thread Starter
Ok so back to the Duramax disassembly process. But first, you should try to gain an overview on the engine internals, turbo and fuel system. Unless buying a new or reman crate motor, your gonna need to know what you have to start with.
50k miles on this engine is barley broken in. I know of a bone stock one that hit 900k without a valve cover removed.. So even a mid 100k mile Duramax could be a direct drop in that runs great for many years of boating. But it all depends on what your looking to do with it.
If possible you should check it running. First the normal stuff like excessive smoke [at idle], leaks or blow by. Also a good time to plug in a scan tool or OBD tool like Torque to check DTCs and perform a Balance Rate Test
[ATTACH=CONFIG]552854[/ATTACH]
Balance rate measures how much fuel the ECM adds or subtracts from each cylinder to idle smoothly. While typically used to isolate bad injectors, it can also expose low compression. As does white smoke at idle.
The next check before striping anything off is to do a compression test. This can be done while in the truck, or just as easily setting on the ground. You can even use the $30 compression test kit from Harbor Freight that comes with the correct head fitting. Removing the glow plugs is pictured below.
[ATTACH=CONFIG]552848[/ATTACH]
Now you know what ya have, power wash and stick it on an engine stand. Next we can start ripping parts off and getting to the fun stuff.
50k miles on this engine is barley broken in. I know of a bone stock one that hit 900k without a valve cover removed.. So even a mid 100k mile Duramax could be a direct drop in that runs great for many years of boating. But it all depends on what your looking to do with it.
If possible you should check it running. First the normal stuff like excessive smoke [at idle], leaks or blow by. Also a good time to plug in a scan tool or OBD tool like Torque to check DTCs and perform a Balance Rate Test
[ATTACH=CONFIG]552854[/ATTACH]
Balance rate measures how much fuel the ECM adds or subtracts from each cylinder to idle smoothly. While typically used to isolate bad injectors, it can also expose low compression. As does white smoke at idle.
The next check before striping anything off is to do a compression test. This can be done while in the truck, or just as easily setting on the ground. You can even use the $30 compression test kit from Harbor Freight that comes with the correct head fitting. Removing the glow plugs is pictured below.
[ATTACH=CONFIG]552848[/ATTACH]
Now you know what ya have, power wash and stick it on an engine stand. Next we can start ripping parts off and getting to the fun stuff.
Last edited by kidturbo; 03-23-2016 at 09:59 PM.
03-25-2016, 02:18 PM
#23
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Thread Starter
With the engine on a stand it's time to remove everything not going back into our boat. This includes the obvious parts like cooling fan and AC compressor, along with a majority of the factory air intake system, EGR valve and cooler. Will also be upgrading the factory oil cooler and filter housing in this process. The exhaust manifolds, up-pipes, and turbo can also be removed at this point. You should take some photo's and tag all the electrical connectors before removing the engine harness. It's best to leave the fuel system between the CP3 and injectors sealed up to avoid contamination until next stage in the process.
[ATTACH=CONFIG]552937[/ATTACH]
Start by removing the wiring harness. The glow plug control module [rear drivers side in pic] can be set aside for now. Glow plugs are actually optional in our marinized Duramax.
[ATTACH=CONFIG]552939[/ATTACH] [ATTACH=CONFIG]552950[/ATTACH]
The EGR cooler is mounted up top, where passenger side up pipe splits off by the turbo in first picture above. The up pipes bolt to the turbo and manifolds with 3 12pt bolts per flange. Save those gaskets, we may use them again. In the second pic the cooler is the shiny looking cylinder beside the turbo. Several different designs have been used since 2004, all in the same location, and all going to the scrap pile..
[ATTACH=CONFIG]552937[/ATTACH]
Start by removing the wiring harness. The glow plug control module [rear drivers side in pic] can be set aside for now. Glow plugs are actually optional in our marinized Duramax.
[ATTACH=CONFIG]552939[/ATTACH] [ATTACH=CONFIG]552950[/ATTACH]
The EGR cooler is mounted up top, where passenger side up pipe splits off by the turbo in first picture above. The up pipes bolt to the turbo and manifolds with 3 12pt bolts per flange. Save those gaskets, we may use them again. In the second pic the cooler is the shiny looking cylinder beside the turbo. Several different designs have been used since 2004, all in the same location, and all going to the scrap pile..
03-25-2016, 02:54 PM
#24
Registered
Thread Starter
Next pieces to come off will be the main intake with pre-heater, throttle valve, and EGR system.
[ATTACH=CONFIG]552951[/ATTACH] [ATTACH=CONFIG]552952[/ATTACH]
Again several different intake setups were used over the years. But for our marine build most of this is not going back on the engine. Do save the MAP sensor [top front in first pic] because that we will use again. Plan is to replace all this factory [mostly emissions related] stuff with a clean and simple Y-pipe that allows us to connect the charge cooler tube to our cylinder heads. Depending on final air charge cooler placement, you can purchase a off the shelf Y-pipe, or build your own from the parts we just removed.
[ATTACH=CONFIG]552953[/ATTACH][ATTACH=CONFIG]552954[/ATTACH]
[ATTACH=CONFIG]552951[/ATTACH] [ATTACH=CONFIG]552952[/ATTACH]
Again several different intake setups were used over the years. But for our marine build most of this is not going back on the engine. Do save the MAP sensor [top front in first pic] because that we will use again. Plan is to replace all this factory [mostly emissions related] stuff with a clean and simple Y-pipe that allows us to connect the charge cooler tube to our cylinder heads. Depending on final air charge cooler placement, you can purchase a off the shelf Y-pipe, or build your own from the parts we just removed.
[ATTACH=CONFIG]552953[/ATTACH][ATTACH=CONFIG]552954[/ATTACH]
Last edited by kidturbo; 03-25-2016 at 02:58 PM.
03-26-2016, 02:07 PM
#26
Registered
Thread Starter
Ok you should have 2 piles of parts by now, things your gonna use and the scarps. Before we pull the turbo off lets get more easy stuff out of the way.
On the passenger side you'll find the fuel filter assembly, remove the rubber lines and unbolt the two bolts facing the filter. Toss it in the keep pile, for now. From each valve cover you have a crank case vent tube tee's into the turbo inlet [second pic]. Remove that tube and toss in the scrap pile, it gets marinized also.
[ATTACH=CONFIG]552977[/ATTACH] [ATTACH=CONFIG]552978[/ATTACH]
Then moving to front of engine, if planning on removing the heads we may as well remove all the accessories, brackets, idlers and thermostat housing. Depending on year and model, the thermostat housing may have a removable [black steel] discharge tube that you want to keep. The Duramax uses two thermostats that open at different temperatures. You can change those based on an open or closed loop cooling application. The complete housing assembly cleanly bolts to the front of the heads with a small recirculation tube down to the water pump.
[ATTACH=CONFIG]552979[/ATTACH] [ATTACH=CONFIG]552980[/ATTACH]
Once all of that's out of the way, you can see the common rail high pressure CP3 fuel pump. Unless upgrading the pump or tearing it down further, just cap off the hose barbs that connect the fuel filter housing and fuel return line for now. As you can see they did a good job of hiding this sucker, luckily they seldom fail...
[ATTACH=CONFIG]552981[/ATTACH]
That takes us down to the turbo and common rail fuel system left on top the engine. From here it gets easy..
On the passenger side you'll find the fuel filter assembly, remove the rubber lines and unbolt the two bolts facing the filter. Toss it in the keep pile, for now. From each valve cover you have a crank case vent tube tee's into the turbo inlet [second pic]. Remove that tube and toss in the scrap pile, it gets marinized also.
[ATTACH=CONFIG]552977[/ATTACH] [ATTACH=CONFIG]552978[/ATTACH]
Then moving to front of engine, if planning on removing the heads we may as well remove all the accessories, brackets, idlers and thermostat housing. Depending on year and model, the thermostat housing may have a removable [black steel] discharge tube that you want to keep. The Duramax uses two thermostats that open at different temperatures. You can change those based on an open or closed loop cooling application. The complete housing assembly cleanly bolts to the front of the heads with a small recirculation tube down to the water pump.
[ATTACH=CONFIG]552979[/ATTACH] [ATTACH=CONFIG]552980[/ATTACH]
Once all of that's out of the way, you can see the common rail high pressure CP3 fuel pump. Unless upgrading the pump or tearing it down further, just cap off the hose barbs that connect the fuel filter housing and fuel return line for now. As you can see they did a good job of hiding this sucker, luckily they seldom fail...
[ATTACH=CONFIG]552981[/ATTACH]
That takes us down to the turbo and common rail fuel system left on top the engine. From here it gets easy..
03-26-2016, 03:26 PM
#27
Registered
Thread Starter
[ATTACH=CONFIG]552982[/ATTACH]
From a good "how to" write up on Duramax Forum that goes into the Turbo removal details. Its basically 3 bolts, 2 electrical plugs, 2 water cooling tubes, and oil pressure and return lines. The exhaust we took off earlier. We can set that puppy on the shelf, or send it out to be cleaned and inspected.
Next I want to move to the oil cooler and leave the fuel injectors alone. This is because unless your tearing the heads off, it's safer to leave the fuel system sealed up. Can't say the same for the OEM oil cooler setup, it's out of here. Not a terrible design, just to too small and a bad location for marine use.
[ATTACH=CONFIG]552983[/ATTACH] [ATTACH=CONFIG]552984[/ATTACH]
You may have noticed the cooler / filter combo is connected directly to our water pump up front. This is because the Duramax coolant flows from the front to the back of the engine before entering the block. So while we plan to upgrade our cooler and relocate the oil filter, we also need replace that coolant routing tube. There is several kits on the market to relocate the oil filter, but only a couple that fit our marine build and Duramax block.
[ATTACH=CONFIG]552986[/ATTACH] [ATTACH=CONFIG]552985[/ATTACH]
All the builds I've worked on to date shared this adapter from PPE. Their cooler delete kit consists of a CNC machined block adapter threaded for AN fittings. They also include an adapter plate to reconnect the coolant tube to rear adapter plate. This setup allows removing the filter/cooler assembly, but retains the oem tube from the water pump. It can be improved upon, but for now our primary goal is to get the oiling upgraded to marine standards.
[ATTACH=CONFIG]552988[/ATTACH]
From a good "how to" write up on Duramax Forum that goes into the Turbo removal details. Its basically 3 bolts, 2 electrical plugs, 2 water cooling tubes, and oil pressure and return lines. The exhaust we took off earlier. We can set that puppy on the shelf, or send it out to be cleaned and inspected.
Next I want to move to the oil cooler and leave the fuel injectors alone. This is because unless your tearing the heads off, it's safer to leave the fuel system sealed up. Can't say the same for the OEM oil cooler setup, it's out of here. Not a terrible design, just to too small and a bad location for marine use.
[ATTACH=CONFIG]552983[/ATTACH] [ATTACH=CONFIG]552984[/ATTACH]
You may have noticed the cooler / filter combo is connected directly to our water pump up front. This is because the Duramax coolant flows from the front to the back of the engine before entering the block. So while we plan to upgrade our cooler and relocate the oil filter, we also need replace that coolant routing tube. There is several kits on the market to relocate the oil filter, but only a couple that fit our marine build and Duramax block.
[ATTACH=CONFIG]552986[/ATTACH] [ATTACH=CONFIG]552985[/ATTACH]
All the builds I've worked on to date shared this adapter from PPE. Their cooler delete kit consists of a CNC machined block adapter threaded for AN fittings. They also include an adapter plate to reconnect the coolant tube to rear adapter plate. This setup allows removing the filter/cooler assembly, but retains the oem tube from the water pump. It can be improved upon, but for now our primary goal is to get the oiling upgraded to marine standards.
[ATTACH=CONFIG]552988[/ATTACH]
Last edited by kidturbo; 03-26-2016 at 03:31 PM.
03-26-2016, 10:50 PM
#28
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Thread Starter
Internal Upgrades
If you've purchased a good clean low mileage 07 or newer engine and can live happily with around 500hp, then there is no need to dive any deeper into your engine. You can buy a fully marinized Duramax from MarineDiesel Sweden rated between 400-500hp, rest assured it came straight off the same production line in Dayton OH too.
[ATTACH=CONFIG]553000[/ATTACH]
So if that's good enough power, bank $10k, and skip this section. You can go to the next page when I pick back up at fuel system upgrades. Here is a list we are going to address along the way.
For everyone else, lets rip the heads off and take a look at a stock Duramax internals.
You can now remove the hard steel fuel lines from the CP3 pump to the injectors and stick them in a large ziplock. The smaller black lines are fuel return, push in on the locking rings and they release from the injector top. The fuel rails unbolt from the primary intakes with two bolts, cap them off and store in a ziplock too. Just be sure to cap off all the fuel fittings so not to get any dirt in anything. Don't worry if you do, Inectors are only $300ea now...
[ATTACH=CONFIG]552999[/ATTACH]
Once all the fuel lines are off you can unbolt the injector hold downs from the head. A 12mm socket if I recall, and the injector should slide up and out of the head with a little persuasion. This all depends on how much carbon is built up on the tip.. LABEL THEM by cylinder #, wrap in bubble wrap and store in a safe place.
[ATTACH=CONFIG]553001[/ATTACH]
Next we can pull the 2-piece valve covers and unbolt the valvetrain. The Duramax uses a single solid roller lifter camshaft, connected to a rail type rocker arm setup, that operates 4 valves per cylinder. These OEM pieces will easily handle well into the 700-900hp range with a couple easy mods. Not bad for Isuzu...
[ATTACH=CONFIG]553003[/ATTACH]
[ATTACH=CONFIG]553000[/ATTACH]
So if that's good enough power, bank $10k, and skip this section. You can go to the next page when I pick back up at fuel system upgrades. Here is a list we are going to address along the way.
- Internal Upgrades
- Oiling System
- Fuel System
- Turbo Options
- Exhaust
- Cooling System
- Intake / Charge Cooling
- Electronics
- Transmission & Drives
For everyone else, lets rip the heads off and take a look at a stock Duramax internals.
You can now remove the hard steel fuel lines from the CP3 pump to the injectors and stick them in a large ziplock. The smaller black lines are fuel return, push in on the locking rings and they release from the injector top. The fuel rails unbolt from the primary intakes with two bolts, cap them off and store in a ziplock too. Just be sure to cap off all the fuel fittings so not to get any dirt in anything. Don't worry if you do, Inectors are only $300ea now...
[ATTACH=CONFIG]552999[/ATTACH]
Once all the fuel lines are off you can unbolt the injector hold downs from the head. A 12mm socket if I recall, and the injector should slide up and out of the head with a little persuasion. This all depends on how much carbon is built up on the tip.. LABEL THEM by cylinder #, wrap in bubble wrap and store in a safe place.
[ATTACH=CONFIG]553001[/ATTACH]
Next we can pull the 2-piece valve covers and unbolt the valvetrain. The Duramax uses a single solid roller lifter camshaft, connected to a rail type rocker arm setup, that operates 4 valves per cylinder. These OEM pieces will easily handle well into the 700-900hp range with a couple easy mods. Not bad for Isuzu...
[ATTACH=CONFIG]553003[/ATTACH]
Last edited by kidturbo; 03-26-2016 at 11:13 PM.
03-28-2016, 12:07 PM
#29
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Next we can pull the 2-piece valve covers and unbolt the valvetrain. The Duramax uses a single solid roller lifter camshaft, connected to a rail type rocker arm setup, that operates 4 valves per cylinder. These OEM pieces will easily handle well into the 700-900hp range with a couple easy mods. Not bad for Isuzu...
[ATTACH=CONFIG]553003[/ATTACH]
03-28-2016, 06:37 PM
#30
Registered
Thread Starter
Once you pull the heads we find the #1 point of failure in these engines turned up, the pistons. The first pic below is from my LLY engine when it still had stock pistons. The head studs are not factory. While the Duramax does employ a 6 bolt per cylinder clamping pattern, they also used torque- to-yield head bolts from factory. In fact 90% of the bolts on this engine are "single use" torque- to-yield.. So keep that in mind. Switching to good head studs will pretty much guarantee you'll never blow a gasket in the future.
[ATTACH=CONFIG]553127[/ATTACH]
Next lets examine examples of piston failures. Couple from my own LLY, and one from Dave's marinized [stock bottom end] LMM. This is where industrial or marine standards part ways from light duty trucks. The OEM pistons used after 2006 in the LBZ/LMM were improved upon with a different bowl design and lower CR making them less prone to failure than LB7/LLY's. However they are all cast aluminum and won't handle prolonged abuse either. Abuse being high EGT's or long injector pulse width and a bunch of timing advance.
[ATTACH=CONFIG]553130[/ATTACH][ATTACH=CONFIG]553133[/ATTACH][ATTACH=CONFIG]553135[/ATTACH]
Many drag racers and truck pullers have successfully pushed the OEM LBZ/LMM pistons well into 600-900hp range without failure. For 10-15 seconds at a time... They don't care much for 10-20 minutes of high RPM blasting that would be typical in a cranked up diesel boat. Even GM caught on to the cause and released a tech bulletin to alert dealers how to identify if someone was running a modified tune while under warranty.
[ATTACH=CONFIG]553136[/ATTACH]
[ATTACH=CONFIG]553127[/ATTACH]
Next lets examine examples of piston failures. Couple from my own LLY, and one from Dave's marinized [stock bottom end] LMM. This is where industrial or marine standards part ways from light duty trucks. The OEM pistons used after 2006 in the LBZ/LMM were improved upon with a different bowl design and lower CR making them less prone to failure than LB7/LLY's. However they are all cast aluminum and won't handle prolonged abuse either. Abuse being high EGT's or long injector pulse width and a bunch of timing advance.
[ATTACH=CONFIG]553130[/ATTACH][ATTACH=CONFIG]553133[/ATTACH][ATTACH=CONFIG]553135[/ATTACH]
Many drag racers and truck pullers have successfully pushed the OEM LBZ/LMM pistons well into 600-900hp range without failure. For 10-15 seconds at a time... They don't care much for 10-20 minutes of high RPM blasting that would be typical in a cranked up diesel boat. Even GM caught on to the cause and released a tech bulletin to alert dealers how to identify if someone was running a modified tune while under warranty.
[ATTACH=CONFIG]553136[/ATTACH]
