Cummins QSM11

[rsmith]

Saw these for sale on Marketplace for 100k. Cost 50k to make it to 1000 hours? I thought QSM11 was the greatest thing since sliced bread.


I have a complete pair of 2018 low hr (960) Cummins 715hp engines with gears trolling valve ,shifter, command box ,displays .run perfectly.just had 1000 hrs service done . Both engines have new turbos ($5500 each) aftercoolers ($7700 each) new exhaust manifolds ( $2200 each) all coolers and heat exchangers removed tested repainted . Total bill was almost 50k . Repowering only for added fuel range and going different direction with the boat. Currently in vessel for sea-trial if serious. All records on hand and professionally maintained warranty on service that has just been completed .

 

[madhatter1]

Post thermal meltdown. They are only good for low 500’s where they run great if not over propped.

 

[Bob Bradley]

Yup. Way too much hp at 715. They burn up the exhaust manifold and turnbo gaskets if you run them at over 20 gph each. My 535 hp QSM11s move my 45c at about 22 kts at that rate. She'll top out over 29 kts, but that takes 25gph per engine.

 

[Captain Ralph]

Tony had a nice tip about the dry exhaust manifolds on the 11s.
#1, don't over prop, even under prop a little to keep the exhaust temps down.

Past this, the 11s are bomb proof. Want economy? keep your foot off of the throttles.

 

[Eddieclemons]

I really don't like crunching the numbers and I self wrench, but a 1000 hour service with New parts to include turbos is going to be right there on any 700-800hp Cat, Cummins, or Man. No experience here with MTUs.

 

[Pascal]

I really don't like crunching the numbers and I self wrench, but a 1000 hour service with New parts to include turbos is going to be right there on any 700-800hp Cat, Cummins, or Man. No experience here with MTUs.

I don’t know about that… I ve run 1400hp 3412Es which had 5000+ hours when sold with original turbos, after coolers, injectors etc. Same with a pair of 1650hp C32 with 4000+ when sold also with original turbos, injectors etc. After coolers obviously upgraded being C32s

Same with the 2000hp 16V2000 I currently run. They were rebuilt at 4000 hours but still had original turbos injectors etc.

So requiring new turbos, coolers, exhaust manifold etc at 1000 is far from routine

 

[Captain Ralph]

So requiring new turbos, coolers, exhaust manifold etc at 1000 is far from routine

Reads like dock queen engines.
Lack of use, damp air up the exhaust, black water in the coolers, dry injectors,,,,,

 

[cww]

And you wonder why most of us are still running around on the original Detroits

 

[Bob Bradley]

Reads like dock queen engines.
Lack of use, damp air up the exhaust, black water in the coolers, dry injectors,,,,,

And likely got run like he just stole it on the rare occasion that it went out.

 

[Eddieclemons]

I don’t know about that… I ve run 1400hp 3412Es which had 5000+ hours when sold with original turbos, after coolers, injectors etc. Same with a pair of 1650hp C32 with 4000+ when sold also with original turbos, injectors etc. After coolers obviously upgraded being C32s

Same with the 2000hp 16V2000 I currently run. They were rebuilt at 4000 hours but still had original turbos injectors etc.

So requiring new turbos, coolers, exhaust manifold etc at 1000 is far from routine

I was basing my statement on what the OP listed as completed at "his" 1k. No you don't always need NEW or any turbo work and or Exhaust. But if you do CAT Aftercoolers every 6 years your going to spend that 50K. 3406e Aftercoolers, Gaskets, Cat Reman turbos, and impellers are 30K with NO LABOR, NO coolers cleaned, NO heat exchanger cleaning, and NO fluids and filters. Anyway you look at it's 50K on any of the engines I mentioned.

I lost a turbo inlet turbine nut at 2K hours/15 years old possibly, and lucky the aftercooler that already needed changing caught all the flying parts. I have been told that I could have caused the failure by putting it up on plane to fast???? Maybe??? I do know that my reman CAT turbos don't have that nut that can back off.

I do agree that I hope to bring the cost down by flushing my coolers and heat exchangers regularly, inspecting my exhaust and turbos, and I will pop off the aftercoolers at 1K or about 6-10 years depending on when I leave freshwater again.

We have a ton of QSM11 and MAN 800-1300 boats at my club and only one mechanic that drives 2 hours to get here. He does Ultrasonic cleaning for them onsite if replacement isn't needed. He also will install turbo cartridges and or send out for rebuild to get these prices down, but its still in the realm of the OP.

I LOVE my boat, but this game will bring a weak or middleclass man to his knees, Luckily I am currently just one of those and my wife still loves to work and is strong also.

We still a to organize a meet up this summer or fall?

 

[Pascal]

8 years ago when we did the aftercoolers on that pair of C32s it was $30k but that included the housing and pipes needed for the upgraded AC version. Back then I was quoted about $20k for subsequent core replacements. And that’s for the bigger C32s

Still you shouldn’t have to replace turbos that often.

 

[Eddieclemons]

In March of 2021 my 3406 aftercooler was $4400 and a reman turbo was about $6400, As of today they are about $2000 more each. In 2023 I did a set of 3406 Aftercoolers and there were 75 on backorder and about half dozen of those were ordered boat down status, when the coolers came in the prices seem to have made that jump.

 

[Eddieclemons]

8 years ago when we did the aftercoolers on that pair of C32s it was $30k but that included the housing and pipes needed for the upgraded AC version. Back then I was quoted about $20k for subsequent core replacements. And that’s for the bigger C32s

Still you shouldn’t have to replace turbos that often.

Agreed,

Last Fall a C32 Cooler was $7700, plus gaskets, and plus tax. It sounds like your CATS are someone else's now though.

 

[rsmith]

I’ve looked at several boats with QSM11 and every one had had exhaust manifold and head warping problems. Owners would say it was a 28kt boat but the engines were bulletproof as long as you run 18kts. In the sportfish world an 18kt boat hasn’t been competitive since the 80’s.