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- Cummins Marine Forum Topics
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Fuel burn with twin QSB 480 vs twin QSC 500
This topic has 2 replies, has 3 voices, and was last updated by
2 years ago February 19, 2022 at 4:55 am Iām comparing a 2009 Sea Ray 44 flybridge with twin QSC 500 straight shaft with a 2009 meridian 441 flybridge with twin QSB 480 v-drive. Boat displacement and length are similar. I like to go fast and slow but from my research it seems that somewhere around hull speed or 700-900 rpm or 7-9 knots, the QSBās donāt do any better than 1 or 2 mpg whereas the QSCās maybe get 5-7 mpg. At higher RPMās the burn is pretty flat and similar for both. Iām wo…
2 RepliesFebruary 19, 2022 at 11:22 am Instruments/gauges, or ?? is wrong.. The vessel with less weight, less windage and the best ‘bottom /running gear” will typically get the best MPG at hull speeds assuming all is in “ass new condition” ..Longer LWL’s will increase hull speed some in some cases and some round chine narrow “east coast designs” can be “slipperier” in some cases at speeds below 10 kts.. ……………Last Post by:
posted: 2 years ago
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QSM-11 question
This topic has 4 replies, has 3 voices, and was last updated by
2 years ago
February 17, 2022 at 6:29 pm Hello, I am new to this site. I am looking into the purchase of a 2003 Novatec 55 powered by twin QSM-11, 535 HP engines. The vessel has under 700 hours and I’ve been told it has had very little use it was last serviced in 2013. I have read that the QSM-11 engines may have a wet or dry turbo and exhaust system. Do all QSM-11 engines have a dry system or are there some with a wet system. If there may be either system how would I determine w…
4 RepliesFebruary 18, 2022 at 10:56 am Yes, this is Good Vibrations. I have had Volvo-Penta Diesel powered and Iveco Diesel powered vessels but I am not familiar with Cummins Diesel power. The Racors show a concern of fuel stability and I am not certain as to the engines aftercoolers condition having low run time since 2013, and it has been in salt water.Ā Thank you and Tony for your responses and I will be thinking hard about going forward. I didn’t want to cruise at the slowe…Last Post by:
posted: 2 years ago
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Air in cooling water Cummins 6BT Marine
This topic has 3 replies, has 3 voices, and was last updated by
2 years ago February 17, 2022 at 7:20 am My Cummins 6BT 5,9 210hp creates air an overflow of cooling water system if RPM is above 1900. Any proposal what the reason is? Below 1900RPM no air is seen and engine have 450hours since total overhaul. The water-cooled exhaust manifold is renewed but still the problem occurs
3 RepliesFebruary 18, 2022 at 5:58 am Post pictures of the compete engine showing all–no close-upsLast Post by:
posted: 2 years ago
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Rebuilt turbo put on 2008 QSB 5.9l 480
This topic has 3 replies, has 3 voices, and was last updated by
2 years ago
February 14, 2022 at 7:58 pm Iām considering buying a boat with twin QSB 5.7l 480hp (2008) v-drive with about 1200 hrs. It looks like the 1000 hr service (or maybe I should say a service) was done in April of 2019. Do the pics and service invoice tell any story? Does the paint job on the motors, which seem to have a bit of overspray, a little sloppy indicate anything?
3 RepliesFebruary 18, 2022 at 5:08 am Iām not very far along in the investigation to be able to give the more pertinent info. However I need to verify my thoughts against yours as I go through the education process. Buying a boat is tougher these days. So many are neglected and the prices are high. But Iāll find my boat and it will have Cummins and Iāll be better educated and supported and that is THANKS to you guys Tony, Rob and Steve. Youāre much appreciated.ĀLast Post by:
posted: 2 years ago
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6BTA AFTERCOOLER
This topic has 12 replies, has 5 voices, and was last updated by
2 years ago
February 14, 2022 at 4:37 pm Hello. I have a new to me 2002 Tiara Express 35 with 6bta 5.9 engines.Ā We recently installed a new RECON long block and working on the peripherals. Today the mechanicĀ sent me these pictures and told me that the aftercooler core is stuck to the housing and that it looks like previously someone tried to push it out and left it crooked.Ā Also said there was a lot of some type of silicone on the caps that might have been used to create a sealĀ and…
12 RepliesFebruary 17, 2022 at 3:00 pm Hope you have a great Birthday Weekend!Last Post by:
posted: 2 years ago
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6cta belt tensioner issues and coolant pump
This topic has 5 replies, has 2 voices, and was last updated by
2 years ago February 14, 2022 at 9:04 am Good Morning folks! i have a 6cta and i just installed a 28si alternator from a small profile balmar unit. I had to change brackets, pulleys, etc in order to fit. I noticed that the belt tensioner is shaking a lot, cant really remember if it did this before… I am leaning towards changing it but wanted to verify first in here.. Also, i noticed that the coolant pump (3913430) for this engine is bigger than the other, is this an issue? Since …
5 RepliesFebruary 16, 2022 at 2:46 pm My tensioner does not wobble as much which led me to believe maybe not enough tension from the belt and the fact that you went from the balmar tiara setup to the Cummins setup which is two different belts.ĀLast Post by:
posted: 2 years ago
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5.9 vs 6.7 for an Albin 28
This topic has 5 replies, has 3 voices, and was last updated by
2 years ago February 6, 2022 at 1:45 pm I watched the video where Seaboard installed a 6BTA in an Albin 28.Ā SB used a generator center rise exhaust manifold, which worked great. Can a center rise manifold be used with the QSB5.9?Ā The oil line to the turbo might have to be custom.Ā Any other issues? What about a 6.7 in an Albin 28?Ā Did Cummins ever make a center rise manifold for a marine genset?Ā Ā
5 RepliesFebruary 15, 2022 at 7:14 pm The QSB 5.9 380Ā is “close” to the size of a 6BTA 5.9 mechanical.Ā But a high-mount turbo would not be possible unless you had and extra $10+K to add to the job.. Major engineering and design/fabricationĀ needed.Last Post by:
posted: 2 years ago
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Maintenance work qsc 8.3 help
This topic has 9 replies, has 4 voices, and was last updated by
2 years ago February 12, 2022 at 7:02 pm hey everyone looking for a few pointers here and figured you guys can answer my questions, some may seem silly or stupid but want to be sure on stuff before ordered parts engine runs at good temp constant temp, no overheats or anything. But I am not sure when thermostats were last done. should I do them just to do them? or stick with the old say saying if it aint broke dont fix it am I correct there is only 1 thermostat in the engine? also I no…
9 RepliesFebruary 15, 2022 at 7:06 pm Post good pics of all..Last Post by:
posted: 2 years ago
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Exhaust elbow leak ?
This topic has 7 replies, has 4 voices, and was last updated by
2 years ago
February 13, 2022 at 5:50 am Also anyone have any idea what this could be. Started boat, it was after a cold few days and noticed this leak.look closely youāll see bubbling. Also it wasnāt oil but water with black in it. Looking for Ideas bc also after boat tan for a few minutes it just stopped and the leak went away. But Iām calling suspect and think something is upĀ
7 RepliesFebruary 14, 2022 at 3:23 pm I will try that in a little bit for sure thanks youĀLast Post by:
posted: 2 years ago
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6CTA high Nitrite on coolant (DCA Test Strips)
This topic has 1 reply, has 2 voices, and was last updated by
2 years ago February 13, 2022 at 3:10 pm So I changed the coolant on both of my 6CTA’s with regular ethylene glycol (prestone 50/50) and 32 OZ of DCA4 additive on each… After using the vessel for about 6 hours I checked the coolant with some CumminsĀ DCA test strips and I have high 50% freeze point, very high nitrite and 0 molybdenum, that takes me to the last item on the scale (see attached)… What am I looking at here? Did I add too much DCA4? How can I correct this,…
1 ReplyFebruary 13, 2022 at 5:29 pm Probably what happened.. Does it matter? The jury is out my end..ĀLast Post by:
posted: 2 years ago
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Sherwood Pump Model P173?
This topic has 3 replies, has 3 voices, and was last updated by
2 years ago February 12, 2022 at 4:05 am I have an oil seal leak in one of my water pumps and I am trying to determine the model of sherwood that I have. I think it is model P173 but I am unsure. Ā Anyone else have something like this. Ā Ultimate goal would be to replace with an SMX (what model do I purchase?) when these start to have a water seal failure.Ā 5.9 6BTAĀ IN and OUT port is 1.75″ See pics!Ā Thank you for the replies like this in advance!
3 RepliesFebruary 12, 2022 at 1:52 pm Super early SherwoodĀ pump with a press-on gear.. Think of it as a 1716 as to replacement purposes other that both the in & out ports are probably forĀ 1.75″ ID hose….The SMX 1716 pump kit can be special ordered that way if needed.Last Post by:
posted: 2 years ago
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6CTA 8.3 Power Loss
This topic has 14 replies, has 4 voices, and was last updated by
2 years ago
July 13, 2021 at 7:26 pm Hey Everyone, I have a 2003 8.3 6CTA 430HP. Over the past weeks or so lost power and only turn 2275 WOT and slow acceleration No smoke, motor runs good, turbo boost is 20 psi, installed a vacuum gauge on rancor and there is 4-5lbs of vacuum on fuel side, not sure if thatās a problem? Any help would be great. Thank you
14 RepliesFebruary 11, 2022 at 3:24 am For what its worth, i have a 6CTA on a 21000 lbs vessel (Tiara 3500 express) and my props areĀ 24x27x2 3 bladeĀ #8 cup nibral. My vessel makes 2650 rpm full throttleLast Post by:
posted: 2 years ago
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6CTAās Fuel cooler
This topic has 2 replies, has 2 voices, and was last updated by
2 years ago
February 4, 2022 at 11:06 am I have a pair of 6CTA’s and was thinking of removing the fuel coolers and relocating the transmission coolers to the fuel cooler locations. I have read the articles on your web site regarding this just wanting to get your option on this. <br />The boat is a 36 Dorado express with a single 500 gal fiberglass tank that is built in the center of the hull aft of the engines so it seems like the fuel would be cooled somewhat by the surrou…
2 RepliesFebruary 10, 2022 at 3:27 pm The boat is ran at planning speed for 50-60 miles at a time then trolling speed for 5-6 hours then another 50-60 mile run. The fuel tank is intergraded into the hull so the bottom of the tank is in contact with the bottom of the hull. I try and keep the tank topped off so its usually never less than 1/2 full. Ā Ā Ā Ā Thanks for following up to my questions.Last Post by:
posted: 2 years ago
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Oily Residue on Alternator
This topic has 5 replies, has 3 voices, and was last updated by
2 years ago February 8, 2022 at 3:04 pm I have this oily residue on my alternator & alternator bracket.Ā Anyone have a good guess where is coming from? Including a couple general pictures of the engine room as well. Ā
5 RepliesFebruary 9, 2022 at 7:04 am The leak is most likely not at leak but the oil mist/vapors in the engine room be recirculated thru the alternator (back to front) over years of use . Look closely at the back of the alternator.Last Post by:
posted: 2 years ago
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330 6BTA side cover gasket
This topic has 20 replies, has 5 voices, and was last updated by
2 years ago
November 19, 2017 at 8:38 am I’ve got an oil leak from the the side cover on my 330 6BTA. Looks like the gasket is cracked and brittle. Can anyone tell me if I’ll be able slide the side cover out without removing the injector pump? I was planning on removing the aftercooler and fuel block for clearance. Not sure how long the bolt behind the pump is but if it’s 3/4 -1 inch, it should sneak out. Let me know what you guys think. Thanks Vic
20 RepliesFebruary 8, 2022 at 7:44 pm I was curious which injection pump Victor was able to sneak behind to replace his tappet gasket. Thanks VictorĀLast Post by:
posted: 2 years ago
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pop noise when starting 5.9 qsb engine
This topic has 1 reply, has 2 voices, and was last updated by
2 years ago February 8, 2022 at 2:50 pm Hi,we have 2 5.9 cummings qsb engines ,when starting one of the engines gives a pop sound just the once,This happens every time its started but runs ok.
1 ReplyFebruary 8, 2022 at 7:25 pm Not even close to enough info to help……………………………..Why not put “our eyes” in your engine room and all over the boat?Ā History of the engines and the boat itself??Ā That would b a start..Last Post by:
posted: 2 years ago
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QSM11 oil pan heater?
This topic has 2 replies, has 2 voices, and was last updated by
2 years ago
February 8, 2022 at 2:34 pm Is there a benefit and/or need to adding an oil pan heater to the QSM11? Ā
2 RepliesFebruary 8, 2022 at 3:17 pm Thought so! Ā Couldn’t see how they wouldn’t be beneficial. Also sent you a PMLast Post by:
posted: 2 years ago
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QSM11 Change Zincs
This topic has 1 reply, has 2 voices, and was last updated by
2 years ago February 7, 2022 at 4:34 pm Hi, When changing zincs on a QSM11, I close the thru-hull and open the sea strainer (usually cleaning the strainer anyway). Ā I take out the upper large zinc and usually more water drains out and no water comes out. Ā The fuel cooler zinc can also be removed with no water coming out. However, the lower large zinc still has a lot of water come out when the zinc is removed. Ā Is there a way to drain more water out of the engine so the seawater doesn…
1 ReplyFebruary 8, 2022 at 6:17 am “usually more water drains out and no water comes out” That is a confusing sentence…. But I think the simple answer is no, on any engine the water is going to seek it’s own level based on the seawater loop geometry, your LWL, weepage/seepage through the impeller, etc.Ā What does work to control the water flow is to slightly loosen the upper zinc (without breaking the seal) and then remove the lower zinc completelyĀ and th…Last Post by:
posted: 2 years ago
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Too much water from the after cooler condensation plug?
This topic has 2 replies, has 2 voices, and was last updated by
2 years ago February 7, 2022 at 3:39 pm Hi Everyone – Last summer I found out my after coolers were shot, and I replaced them with ones from the new supplier for Cummins, Mota. I pressure tested when I installed on the waterside to 25 lbs PSI with air, and everything held great for hours. I ran them as usual throughout the summer and into the fall, and they’ve only ever been in fresh water.Ā Just today, I took the boat out for a spin to keep the cobwebs off and after my ru…
2 RepliesFebruary 7, 2022 at 9:51 pm Yes, 100% fresh water.I also keep the wolverine pan heaters Ā on 24/7 incase that matters.Ā Based on Ā the article, sounds like nothing to worry about then. It was just the right conditions for a TON of water in the ACās air side. Figured since it was the same in both, its probably nothing to worry about.Ā Should I do anything to get the remaining water out, or just leave them be?ĀLast Post by:
posted: 2 years ago
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QSM11 Dry Exhaust Slip Joint
This topic has 7 replies, has 4 voices, and was last updated by
2 years ago April 16, 2018 at 8:22 am What seals the slip joint in the QSM11 Dry Exhaust system, it looks like in the Cummins manual on quickserve they show some type of insert/seal, but its no where to be found in the parts diagrams? Is it sealed immediately when the manifold is installed, or does it have to run a few hours and blow a little soot to seal up? Can you use something like Fuchs 762 / Silkalene on the slip joint?
7 RepliesFebruary 7, 2022 at 5:37 pm Nothing new——————-If you wanted to spend a month+ of time at a shop like mine, full time with nothing else to do and you had your boat “local” and a spare $10-20K to do the R&D needed,Ā call me.. TonyLast Post by:
posted: 2 years ago
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Fuel burn with twin QSB 480 vs twin QSC 500
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