Official Cummins QSC-500 Thread

Yes it is sbmar.com I made the upgrade a three years ago. Excellent products and customer service.
 
Thanks, but I am looking for a replacement pump. A few years ago, some guys had excellent recommendations of a company that builds quality replacement pumps for these engines - more reliable than the originals.

I don't think Seaboard do a pump for the QSC. Vaguely remember seeing a post by Tony Athens saying that the factory QSC pump was a pretty good unit and didn't require redesigning like the pump fitted to the earlier B & C series.

Edit: Found the post "Sherwood did a good job with this pump.. Other than normal maintenance, you are good to go..
Tony"
http://boatdiesel.com/Forums/index.cfm?CFAPP=31&Forum_ID=602&Thread_ID=54721


Paul
 
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Great info, guys. Thanks! Just back from a 3-day, 150 mile round trip. Very nice.
 
Guys ,
My port engine started to blow some blk smoke on throttle up. It only smokes on the throttling up and only for like a second. Any thoughts ? Everything else is perfect. I've made no changes to anything this season other then adding biobor in shock amounts. I'm about half tru that tank

Any thoughts would help

Rob
 
Black smoke usually relates to too much fuel/too much load. Watch to see if there is a turbo boost difference between port and stb, your port turbo may have issues spooling up.
 
It is probably buried in this long thread somewhere, but does someone have a link for the QSC500 PM schedule?
 
The one in the manual is basically useless - its doesn't cover the most important one - servicing aftercoolers.

I run 75 ish hours per season this is the schedule I am following based on this forum, boat diesel and discussions with my local Cummins techs. I would think the only change for year round use would be oil changes at the recommended interval. The key is the aftercooler is the weak point in the engine - it needs to come off and get disassembled, cleaned tested, and reassembled with grease.

Annual
Change Oil & Filter
Change Fuel Filters (Primary & Secondary) (Spring)
Inspect/Replace Engine Zincs
Clean Air Filters (Spring)
Test Coolant SCA (using test strips)
Backflush Combo Fuel/Gear Oil Cooler
Backflush Heat Exchanger​

Every 2 Years
Replace Belts (Spring)
Change Gear Oil & Clean Filter
Disasemble & Clean After Cooler
Change Raw Water Impellers (Spring)​

Every 3 Years
Disassemble & Clean Heat Exchanger​

Every 6 Years
Check Valve Adjustments
Replace Coolant
Disassemble & Clean Combo Fuel/Gear Oil Cooler​
 
I just went to update above with the oil change interval and low and behold I will take back what I said. I see a new maintenance schedule on Cummins QuickServe that has all above and more! They list the aftercooler at three years, which from my research shows 2-3 years, but my local tech recommended 2 years based on the waters I run and the way we use the boat.

https://quickserve.cummins.com/qs3/portal/service/manual/en/4021481/

You need to register - free, but you need at least one of your serial numbers.

The oil change interval is 6 months/500 hours.
 
Thanks for the PM schedule in the previous post. I was searching the web and that was the conundrum I had. I don't have the engine numbers so I could not enter an ID number to gain access into Cummins. However the list you gave me is a good starting point as I research what people have done on their engines as I search for boats that are for sale.

Unfortunately I am not finding any boats out there that are following the noted PMs. I don't see how someone can spend good money On these larger diesels, and treat them worse than their go kart engine when they were kids.

I just went to update above with the oil change interval and low and behold I will take back what I said. I see a new maintenance schedule on Cummins QuickServe that has all above and more! They list the aftercooler at three years, which from my research shows 2-3 years, but my local tech recommended 2 years based on the waters I run and the way we use the boat.

https://quickserve.cummins.com/qs3/portal/service/manual/en/4021481/

You need to register - free, but you need at least one of your serial numbers.

The oil change interval is 6 months/500 hours.
 
I had the same issue. The boat I found had a record of at least teh aftercoolers being done the year prior to me buying by a Cummins tech so I took that as a good sign. All the other boats I looked at I immediately took 15k off asking to cover any unknowns. I had two offers refused based on that, one of them contacted me two months later to "accept", but I already found the bat we ended up with. The 15k covered a full set of maintenance by a Cummins tech (1,2,3,5 and 6 year) plus the cost of a replacement after cooler just in case.
 
I had the same issue. The boat I found had a record of at least teh aftercoolers being done the year prior to me buying by a Cummins tech so I took that as a good sign. All the other boats I looked at I immediately took 15k off asking to cover any unknowns. I had two offers refused based on that, one of them contacted me two months later to "accept", but I already found the bat we ended up with. The 15k covered a full set of maintenance by a Cummins tech (1,2,3,5 and 6 year) plus the cost of a replacement after cooler just in case.

I am not an engine expert by any means, but I am reluctant to pay less for the boat to account for the lack of PM's on the mains.

Aftercoolers - if these are are in very bad shape, is it not possible for the engine to induce salt water through the mixing elbow? Could a small amount be getting in? Correct me if I am wrong, because I am still learning about the Cummins engines. (I believe for many of the Volvos it is).

Engine Zincs - I am finding many don't even replace these. The internals of all of the coolers are therefore a question mark, and were the engines run hot at times by the PO?

Impellers - same comment. How do you know the engine was not being run close to the red line?

IE, I am concerned there may be some lurking issues with a boat that has not been properly maintained that may not be apparent by a comprehensive Cummins Tech, and it may take another year or two before they rear their head.
 
After I change my oil it turns black again almost immediately. A friend told me it is residual crud clinging to internal parts and recommended draining oil, refilling with new oil and a diesel oil flush additive, running motor and then changing oil again. Do others do that? Do you think it's worth the extra cost?

Thanks
Scott
 
I think it depends on how often you plan to change your oil. The filters will collect the harmfull abrasives that cause engine wear and the lubricating and cooling qualities of the oil does not degrade in a year or 100 hrs of operation. If you change your oil at seasons end run the cleaning additive prior to engine oil change and you will get most of the sludge cleaned off and drained out, What you dont want to do is let the old black oil and moisture just sit in the pan over the off season and corrode the internals. And if you do start the engines to exercise them make sure they come to full operating temp for a while to boil out any moisture that condenses in the engine. The worst thing you can do is run the engine for five minutes every few weeks thinking your doing good.
 
Coolant Capacity is 7.75 gallons

Petcock is just below the alternator.
 

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I figure there are enough threads about boats, and there are plenty of models of boats with these engines and their variants, so, how about an official thread for the engines?

....

Zincs (Boat Zincs dot Com)
E-1 1/2 NPT (E-1Z zinc only) 2" Main (4 per engine)
E-2 3/8 NPT (E-2Z zinc only) 2" Heat exchangers (2 per engine)


should the E-1 and E-2 be swapped? i'm showing E-1 as 3/8"NPT and E-2 as 1/2"NPT.

Also showing
Cummins/Onan
B Series: E-2 (3)
6CTA 8.3: E-2 (3)
QSB Series: E-2 (3)
QSC 8.3: E-2 (4), E-1G (2)
QSD Series: 879194217
QSM Series: E-2, E-1G
3957921 = E-1G
3979452 = E-1G
3970463 = E-2C
5290511 = E-1
68241 = E-2
816000 = 879194217
130-0904 = E-0B
130-1340 = E-1G
130-1341 = E-0B
130-4434 = E-1G


http://www.boatzincs.com/engine-sizes.html


thanks!
 
Just replaced an injector on the stbd side. Was idling rough. Now idles smoothly. No sign of wear or breakage.

On another web site, they really advocate for servicing the after coolers every two years on these engines. They say it is the number one cause for engine failure, along with over propping.

They have you pull the after coolers, take them apart, acid bath (I assume acid), clean, and then they recommend slopping tons of green grease on it to keep the dissimilar metals away from each other and make it easy to take apart next time.

All of the local mechanics here say it isn't a problem with these engines, but being in salt water, I'm going to err on the side of caution.

https://www.sbmar.com/articles/cummins-marine-aftercooler-maintenance/
 
I don’t recall anyone asking this question. On the 420 SB and the 44DB with Cummins 8.3 engines, the exhaust pipes running from the Turbos to the mufflers are considerably different in size right engine from left. Does anyone know what purpose this serves?
Thanks
 
I don't know about this, but people have consistently commented on the greater water flow out of the port side exhaust at idle as compared to the stbd.
 

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