QSM11s installing EGT

[Gimme Time]

I have purchased a twin engine digital EGT gauge set from Rival Motorsports that are made in the UK and plan to install them within the next couple of weeks. EGT stands for "Exhaust gas temperature" as these engines seem to have issues with excessive heat which creates excess fuel burn, exhaust gas manifold leads and turbo issues.

Anyone out there added EGT monitoring and if so what results, benefits did you see from having the additional info. TA whom owns Seaboard Marine out on the west coast has a lot of info on Cummins engines and things to look for and try and improve engine longevity and improved owner knowledge of engine issues he's dealt with extensively. I've read a lot on his site and anything I can do to improve the longevity, maintenance and reduced engine issues is of great benefit for Cuminis onwers imho.

Your thought and comments are welcome on the subject!

 

[PMC]

I have been concidering adding egt / boost guages for some time now, but have not pulled the trigger. I understand the benifits as a diagnostic tool, but also believe that the results are predictable if you load the engine properly. As a for instance the 6cta is quite happy (and proven over time) if you prop it 100 rpm over spec.....I probrably read a lot of the same articles

 

[quality time]

I bought them from Tony and installed last spring. Just like anything else it's fun to watch the gauge at first but after awhile it's just another data point like load and GPH that I use to track engine health. It's interesting to see the EGT's run cooler at higher RPM's and why Tony pushes for that 2000 RPM cruise. The temps increase another 100-200 degrees when running at 1700 and below.

I cruise at 1950 burning 20 GPH, 65% load with 950 EGT temps. I've never really heard a max temp but know others run hotter than me.


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[bmac]

John, I seem to remember my QSM's had EGT data available. I could be wrong as I know my MANs have it available and is a display point on the engine monitors.....my memory is short and cluttered.

 

[Gimme Time]

One of the reasons I went with the Spa model was the setable temperatures alarm and being digital the easier to see pretty exact temperature readings. I very gotten the GPH down from 24/26 at 2,000 to 19.8 20.3 +- so I haven't gotten fully down to where Tony wants them so I feel this will increase my protectionist type of data to keep an eye on them.

I always tried to run my 3126TA Kitty Cats before no more than 80- 85% of what she'd top out at which was 2,800. These QSM11s will hit 2340 & 2360 when the electronic governers kick in. WOT supposed to hit 2300+ so the old rule of thumb for 80-85% would be 1840 & 1960+- rspecfully which seems high IMHO. The big key seems to be more issues running a little slow than a little higher to help keep the EGT in line.

Anyone with specific knowledge please feel free to chime in as safety is my priority with these guys!

 

[Havana Shamrock]

Took the boat out yesterday for a shakedown run and thought of your post, so I ran through the smart craft display and found "manifold temp" is that what you are looking for? By the way your model is a DB not SB sorry it's my OCD kicking in.

my boat was propped totally wrong when we sea trailed her. She wouldn't hit WOT the props where supposed to gain better fuel economy (mid range) whatever that means?all it did was load up the engines and blew both exhaust gaskets (owner paid$10,000) for repairs. He also ran the boat harder than I do as I went for the demo ride he slammed her to full throttle as I ease into it.
all I can do is keep up on all maint as there's not much to keeping them running I'm not the guy who will mess with the stock set up to gain .8 GPH so far 2 seasons and they're just fine.

 

[quality time]

Tony's magical GPH is 18.6 at 2000 RPM but I'm comfortable burning 20 GPH. I feel that's a good compromise for me between speed loss and engine longevity since I don't need these engines to last 20,000 hours in a commercial application. I've already reduced pitch by an inch and don't think I'd be happy with my cruise speed if I was to reduce any more. Basically, I set my cruise RPM by the 20 GPH mark. If I'm heavy on fuel I may be at 1920 but will kick it up closer to 2000 once light while still maintaining that 20 GPH burn.

What load % are you seeing?

 

[Storytime]

Just installed them this weekend on my 48. High water has not let me get out and run yet. Props tuned, aftercoolers, heat exchangers, and all coolers pulled and cleaned. Reset the exhaust manifold on the port to fix a small leak, although it looked in pretty good shape. Going to get a good baseline of numbers and then start working on the props to fine tune to numbers like quality time.


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[quality time]

We were out yesterday and I noted my EGT temps. They were running 875 and 925 degrees @ 1950 with the water temp being around 68 degrees.


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[Gimme Time]

Sorry I hadn't responded sooner but little or no internet in our marina as new system being installed now and the cellar was basically dead from everyone trying to use it.

Your welcome to correct me but my 2006 Sea Ray is a 52 SB (Sedan Bridge) not sure what your DB stands for.

Brian, you are correct as there is a manifold temp reading on the Smart Craft panel but that is ahead of the turbo as I understand which could be wrong. If I recall anything under 1,000 degrees and you should have little issue.

What im understanding is in lower RPM do to sea conditions and not wanting to pound the boat charging through rough seas is when the biggest issues occurr. Last weekend I was coming back from the Urbanna Cup races directly into wind out of the East blow 20-30 directly into the mouth of the Rappahannock river giving me 4-6' short choppy seas.

Idea crusing speed was in the 10.5 to 13.5 which keep the bow up enough so we weren't slugging along but that's not supposed to be idea engine load conditions. The GPM, RPM & engine load % are all ok and appears to be fine. I'm lead to believe that's not a good speed conditions loads wise based on good EGT readings I didn't, don't yet have so that along with 1700 to 1850 which are know issues is what I want to monitor and take control of.

Planning on having the EGT system installed before my trip north up through Long Island sound as far as Newport & Block Island, RI in Juky & August.

just had friend last fall drop 30K resolving issue with blown manifold gaskets, manifolds, turbo issues and lots of broken bolts on two QSM11s 2002-03 model years engines. I'd obviously like to mitigate, prebpvent where I can and was a few boat $ if it prevents a lot of boat ?.

love the boat but like all of them ya gotta try and find the weak spots and help protect the proactively if possible over reactivity if require imho. looks the cost the parts and install should be under 2k.

ill up date the cost and readings probably in late August when we're home for those that are interest!

Keep em all happy and more importantly save and everyone will have a great dummer

AJ

 

[Havana Shamrock]

John, I have the same boat as you and the Sea Ray model designation is DB for sedan bridge I don't think they even make an SB.
so your saying that 1700-1850 is where the manifold gaskets are known to fail? My cruise is 1800-1850 and I do most of my travel at 800-1000 (85%) of the time. Both gaskets where replaced 3 years ago and now I see a soot spot on the port motor As I stated I donor abuse my motors and now I'm wondering if it matters what rpm /load you put on them? Yesrtersay I was traveling in the Atlantic at 1850 with a 73% load this is e problem spot your saying?

 

[quality time]

Joe, all I can tell you is that higher RPMS = lower EGT's, assuming your fuel burn is within spec. What is your GPH at 1850?

My highest EGT readings are between 1400-1800 so I see why Tony recommends 2000 for cruising. Just kicking mine up 50 RPM the other day lowered my EGT's by 25 degrees.

I don't think you have much choice if sea conditions dictate running at lower RPMs for a few hours here and there.

 

[Converse48]

Aaron- I know you've told me before, but I am old and forgetful... what speed do you achieve at your 20 GPH cruise? Thanks

 

[quality time]

Aaron- I know you've told me before, but I am old and forgetful... what speed do you achieve at your 20 GPH cruise? Thanks

I average 21-22 knots. 23 in my shallow river :smt001

 

[Havana Shamrock]

Joe, all I can tell you is that higher RPMS = lower EGT's, assuming your fuel burn is within spec. What is your GPH at 1850?

My highest EGT readings are between 1400-1800 so I see why Tony recommends 2000 for cruising. Just kicking mine up 50 RPM the other day lowered my EGT's by 25 degrees.

I don't think you have much choice if sea conditions dictate running at lower RPMs for a few hours here and there.

My numbers where 1850 with 19.7-20.3 GPH

 

[quality time]

My two cents, I would try to pick up another 100-150 RPM by reducing pitch without increasing fuel burn. My props are now 28x31 with #5 cup. I will probably take some cup out if I have a reason to tune the props.....not that I'm looking for one.

 

[Gimme Time]

Gentlemen,

I want have my EGT gauge installed till around the 20th of July while some other work is being done. 1900 I'm burning Port 21.2, Starboard 20.6, 22-23 knots which is fully loaded with fuel & water. The props had some taken off before I purchased and the fuel rate came down from 23-24 to where I am now. Not in the sweat spot yet but considerably better.

Rather than me tell you how little I know about the QSM11m model Cummins that I and many others have, I suggest you go do a little reading on Tony's Tips at SBMAR.com. I have no involvement with SBMAR.com at all but how found tons of info here. Tony was a big contributor of info & response on BoatDiesel.com and eventually started his on site. Lots of great info on BD and more detailed on Cummins which a lot of us have on Tony's site.

Cummins engines from what I have read, been exposed to over the last 10 months need considerably more TLC than the 3126TA Kitty Kate I've had for the last ten years IMHO. I and a friend of mine do a lot of our own work & research as I wouldn't begin to say I'm a mechanic. I want my boat and equipment to be in as good a shape as I can make within reason. Short cuts come back to haunt and make for lousy boating seasons and PMA is a must.

Most all planing boats are over propped for speed when they hit the show room floor cause we all want to know how fast will she Cruise !

Regarding the DB vs SB, the 2006 52 Sedan Bridge is how Sea Ray markets this boat so tell me where the DB comes into the conversation related to the Sedan Bridge so I'll learn something else today!

 

[quality time]

There's never been an explanation but it is what it is. Sedan Bridge nomenclature has always been DB. Whether it be a 400DB, a 58DB or anything in between.

Just like Sundancer's are DA's not SD's.

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[Converse48]

DA. DB. It's all Marketing's fault.

 

[cod]

I've had my boat since the end of '09 and put about 900 hours on the engines. I now have 1800 hours. So I will add my 2 cents.

First, John. I'm curious why the QSM's require "considerably" more TLC? Other than the poor design element of the dry exhaust which causes excess heat eventually causing the exhaust manifold gasket to fail at roughly 1,000 hours, these are fairly maintenance free engines. Other than that issue, I don't know of any other additional TLC that is needed over the CATs but I admit I'm not familiar with the CATS. You have the usual heat exchanger and aftercooler maintenance which I thought was required with other manufacturers. There is the 1,000 hour valve adjustment. But these are items that I wouldn't consider constant or considerable TLC. Even the water impellers last an extremely long time in my experience. I read on boatdiesel someone went 5,000 hours on one set of impellers. Btw, there is a trick to replacing them to avoid having the cam and key fall out if you need that info. I guess my point is my experience over the last 7 years are these are amazing engines.

Joe, I personally did an exhaust mainfold gasket job on my port engine probably 5-700 hours ago with no issue. If you have a gasket failure after only a couple of hundred hours, I will bet my bottom dollar it has nothing to do with your cruise speed. Actually, according to Tony, the higher RPM you run, the quicker the gasket is going to fail. I'm purely guessing but your failure could be from a warped manifold. Did the mechanic check for straightness? Something I'm sure you will never know. Did he use the same bolts? They should also be changed. It is also suggested the manifold should be replaced with a gasket job but I did not. The manifold is a two piece unit and needs to be checked for straightness on perfectly flat surface. Anyway, according to Tony its not IF its going to fail but when and it is usually around 1,000 hrs. depending on how you run the boat. He actually told me to live with it when I was picking his brain prior to the gasket job. I decided to do it anyway. I know I now have a small leak on my starboard side which I will need to address but that will be a much harder job being on the outside of the engine room. I may opt to have someone else do it with a careful watch.
Other QSM issues that are one time fix and not maintenance are the heat exchanger bracket that develops a crack. I had an additional thicker bracket made creating from a template I had made. There was also a tranny cooler bracket that had a recall. Anyway, that's my 2 cents. Always looking to learn more.