Official Cummins QSC-500 Thread

Does anyone have a tutorial, instructions, or a video link to how to properly set the valves on a QSC 500? I believe every 500 hours they should be done. Just looking to get some more research and background knowledge on how it is done before I dive into it. Any tips and tricks are helpful too! Thank you!
 
Ok what oil pressure do you see on your QSC's at 2300 RPM. Is it normal to see a 10 psi difference between engines?
 
Ok what oil pressure do you see on your QSC's at 2300 RPM. Is it normal to see a 10 psi difference between engines?


Not sure of the exact pressure at 2300, but mine run at a low of 30psi at idle after cruising and a high of 65psi. There has always been exactly a 10psi difference from the sea trial to last Saturday when we had it out. My port engine is always higher...

Bennett
 
Mine have an 11 PSI difference between them, and the starboard is always higher once I get above idle speed. Doesn't matter if I'm running 2300 RPM, or WOT. To answer your question, at 2300 RPM my port is 48 PSI and my starboard is 60 PSI.
 
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Mine also are always split by about ten PSI across the entire operating range. Port reads higher. Sounds like there is no rhyme or reason to it.
Rusty
 
Oil pressure...
At near 2300RPM my oil pressures are about 61 / 52 psi port / starboard.

My understanding is this is normal due to the extra plumbing required to bring the filter to the inboard side of the port engine.

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Has anyone replaced their sea water pump inlet elbow with a 90 degree fitting? On the 44DB, the port engine pump's inlet hose is oriented aft with the hose itself approaching the engine from the front which requires the hose to make a 180 degree ridiculously tight turn to connect to the pump. The hose I was able to find will not make the turn in the available space. The 45 degree fitting interferes with the engine mount stringer if it is turned to meet the hose directly. The simple remedy would be to install a 90 degree fitting and orient it forward. I've tried SB Marine but they don't offer it and foe some reason can't order one. I've scoured the web and have not found a source yet.
Any ideas would be greatly appreciated.
Rusty

Hey Rusty,
After taking possession of my 44DB in 2017, I had quite a bit of maintenance done where the boat was, at Plymouth Brewer Marine, before making the trek North. The intake hoses were all replaced as preventative maintenance. I upgraded to what the guys at Plymouth Brewer called "the last hoses I would ever need"! They used these blue, Shields Nautiflex Hi Temp, corrugated hoses:

upload_2020-4-20_0-37-51.png


I hope they were right...not cheap stuff!

If I remember well, they did reroute this hose to the water pump as this hose didn't like to bend easily. The picture is of the port intake hose that goes to the pump.

I can't recall the exact details of what they did, and the paperwork is on the boat. If I can ever get on board, I will take a picture of what was done.

You may be able to get some information from Brewer if you give them a call.
 
Here are the pressure readings at different RPM's my surveyor observed during my sea trial. He sated they were consistent with what he expected to see.
Screen Shot 2020-04-20 at 10.44.46 AM.png
 
Hey Rusty,
After taking possession of my 44DB in 2017, I had quite a bit of maintenance done where the boat was, at Plymouth Brewer Marine, before making the trek North. The intake hoses were all replaced as preventative maintenance. I upgraded to what the guys at Plymouth Brewer called "the last hoses I would ever need"! They used these blue, Shields Nautiflex Hi Temp, corrugated hoses:

View attachment 82747

I hope they were right...not cheap stuff!

If I remember well, they did reroute this hose to the water pump as this hose didn't like to bend easily. The picture is of the port intake hose that goes to the pump.

I can't recall the exact details of what they did, and the paperwork is on the boat. If I can ever get on board, I will take a picture of what was done.

You may be able to get some information from Brewer if you give them a call.
Thanks, Yeah that stuff id really expensive and hard to find here. I looked all over and the minimum purchase was like 25 feet or something like that so I went another direction. I built a special SS elbow to make the turns required and was able to use reinforced exhaust hose that makes the 90 degree bent with no problem. Thanks for sharing.
Rusty
 
Thanks, Yeah that stuff id really expensive and hard to find here. I looked all over and the minimum purchase was like 25 feet or something like that so I went another direction. I built a special SS elbow to make the turns required and was able to use reinforced exhaust hose that makes the 90 degree bent with no problem. Thanks for sharing.
Rusty

Good stuff. FWIF, I think this is a picture of the elbow Brewer installed. I'm not 100% positive though...it is a crop of a picture I took of (I think) the outboard side of the port engine:

upload_2020-4-20_11-38-43.png
 
Good stuff. FWIF, I think this is a picture of the elbow Brewer installed. I'm not 100% positive though...it is a crop of a picture I took of (I think) the outboard side of the port engine:

View attachment 82769
This is what I made up of 314 SS pipe 3/16 wall. Made the R&R of the water pump much easier too!
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So had something weird happen last night. Went for a a sunset cruise, out for 2 hours came back to the dock and the port motor would not shut off from the switch??? If I tapped it you could hear the starter try to engage but the "off" position would not shut the engine down. Went into the engine room and had to pop the breaker on the panel to shut it off. Any ideas? I am headed back to the boat today to pay with this. All I have added recently was the NEMA 2000 vessel view module to feed data to the MFD's but worked fine last outing.
 
So had something weird happen last night. Went for a a sunset cruise, out for 2 hours came back to the dock and the port motor would not shut off from the switch??? If I tapped it you could hear the starter try to engage but the "off" position would not shut the engine down. Went into the engine room and had to pop the breaker on the panel to shut it off. Any ideas? I am headed back to the boat today to pay with this. All I have added recently was the NEMA 2000 vessel view module to feed data to the MFD's but worked fine last outing.
On the 44DB we have key switches on the main power panel in the salon. Do you on the DA? If so the obvious thing to have done would have been to turn off the key switch so I’m assuming you would have done that first. I think I would remove the switch and use a multi meter to determine whether the switch is opening in the off position.
Good luck, I can’t imagine how adding the NEMA 2000 module could affect the ignition circuit.
Carpe Diem
 
Ok so went back today and figured it out. Unplugged the vessel view module that feeds the MFD's and solved the issue. I have 2 hubs with blanks in both. I had it plugged into the port hub and it worked for 2 trips and then acted up. I unplug it and now all is well. I plug it into the starboard hub and the issue follows it and the starboard engine won't shut off. I feel the module and it is hot as balls so I am thinking there has to be an issue with this module. Everwhere I have read you just plug it into one hub....??? But the diagram does show a "Y" harness for some applications. Anyone have some experience here?
 
Ok so went back today and figured it out. Unplugged the vessel view module that feeds the MFD's and solved the issue. I have 2 hubs with blanks in both. I had it plugged into the port hub and it worked for 2 trips and then acted up. I unplug it and now all is well. I plug it into the starboard hub and the issue follows it and the starboard engine won't shut off. I feel the module and it is hot as balls so I am thinking there has to be an issue with this module. Everwhere I have read you just plug it into one hub....??? But the diagram does show a "Y" harness for some applications. Anyone have some experience here?


By "hub" do you mean J box?
 
Ok so went back today and figured it out. Unplugged the vessel view module that feeds the MFD's and solved the issue. I have 2 hubs with blanks in both. I had it plugged into the port hub and it worked for 2 trips and then acted up. I unplug it and now all is well. I plug it into the starboard hub and the issue follows it and the starboard engine won't shut off. I feel the module and it is hot as balls so I am thinking there has to be an issue with this module. Everwhere I have read you just plug it into one hub....??? But the diagram does show a "Y" harness for some applications. Anyone have some experience here?
I'd say there is something awry with the module. Should that Vessel View module apply +12V to pin "F" in the JBox Smartcraft connector then the ignition will always be on; even regardless of the key switch or ignition switch positions. You are correct that the only way to shut down the engine was to switch the breaker off. Pin "A", by the way, is +12V battery power to the Smartcraft network. So it appears there is a fault in the module. The Vessel View module is hot probably due to the current it was passing.
The "Y" harness provides Port systems data to the Vessel View module; port fuel level would be one example. I believe you will find the Vessel View should be connected to the Starboard side of the network.
upload_2020-5-10_7-3-46.png
 
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I'd say there is something awry with the module. Should that Vessel View module apply +12V to pin "F" in the JBox Smartcraft connector then the ignition will always be on; even regardless of the key switch or ignition switch positions. You are correct that the only way to shut down the engine was to switch the breaker off. Pin "A", by the way, is +12V battery power to the Smartcraft network. So it appears there is a fault in the module. The Vessel View module is hot probably due to the current it was passing.
The "Y" harness provides Port systems data to the Vessel View module; port fuel level would be one example. I believe you will find the Vessel View should be connected to the Starboard side of the network.
View attachment 84376
So do I need a "Y" harness to come out of the vessel view module to go to port and starboard hub? Or just plug it only into the Starboard hub? Also does this module need power from the NEMA network our should I isolate it from NEMA power?
 
So do I need a "Y" harness to come out of the vessel view module to go to port and starboard hub? Or just plug it only into the Starboard hub? Also does this module need power from the NEMA network our should I isolate it from NEMA power?
So, I can talk about the VV7's in that they obviously get their power from the Smartcraft networks. Their harness connects to both Starboard and Port Smartcraft Jboxes and ignition on signal is fed from both sides isolated using diodes so regardless which engine is operating the monitor is operating. The below is a picture showing that arrangement (Note that the key switch pin "F" is the ignition on signal to the VV. Pin "A" from the starboard side is the +12V power.
As, it seems, your new VV monitor only needs to connect to one or the other engine to operate and it powers up regardless of which engine is running I would surmise that it is powered through the NMEA 2000 network.
upload_2020-5-10_7-45-32.png
 
What is DTS?

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