QSM11 running temperatures

[Mark Wright]

Is there a chart that gives an idea of the temperatures a  QSM11  670 hp should run at?

I know the thermostats open at 160 degF and mine get to about 175 @ 22knots 70% load

but lately have been creeping to about 178- 180 .At what temps should I start to worry about doing the Heat

Exchangers?

 

Topic

[Tony Athens]

Your Power curve will be attached as soon as Corey sorts out a current glitch.. If you want is sooner, drop me a note .

Just stay on course with what ever you are doing now.. .

If you wanted, you could get a 180-185 Stat and make things a tad more efficient and keep the oil cleaner if you were into oil analysis..

[Richard Nye]

Engine S/N: 35103646
Date of Mfg: 07/04
Air cooled manifold & turbo
Fuel burn at my normal cruising speed of 8kts is about 4.5 gph
Yes, I do run it up to WOT and the temp may go from 156F to 157F. No more than that.

Thanks Tony

[Tony Athens]

You actual engine load IS NOT determined by RPM but by the GPH you burn at curve vs the engines power curve.

Post your engine serial number or CPL and I’ll peek at what exact “450” you have.

In general, low loads on electronic engines do not cause any issues.. Do you ever run it up to WOT and check base line numbers?

[Richard Nye]

I have a single QSM-11, 450hp on my 100,000 lb trawler. I normally operate it at about 1250 rpm, so very light loads. The coolant temperature has always been 156F. It never changes regardless of sea temperatures from 50F to 80F and up to 2,100 rpm.

My question, is 156F too low? Will this create any problems, or maybe incomplete combustion. The cool temperature must be good for the bearings, etc., and I normally don’t need to turn on the ER exhaust fans.

Thanks! Richard

[Tony Athens]

Your temps are fine……………As the the internal condition of the seawater components as to “Marine Age”, that could be a different  if you park in saltwater and do not fresh water flush..Eventually it will catch up with you.

Tony

[Larry Backman]

Too hot?

2500 hours of experience with a single QSM – mine runs steady at 165 at 66-67% load in water temperature to 75 F.  In real warm water here, say 78F it might creep up to 167-168 but never ever above 170,

 

i saw 170 the first year I owned the engine and the H\X was a filthy mess!

[Tony Athens]

No chart but 25+ yrs of direct experience with the QSM11 tells me that once you have a baseline that seems to be “your normal” over a period of a few yrs ( 175F-ish) , I ‘d be totally comfortable at 185F-ish.. The engine will not be hurt even if it’s steady at 195F-ish, but since something had changed, that tells you things on the seawater side of the cooling system needs to be addressed………………………….BTW, this would apply to any Cummins Marine engine that uses 160F stats..

Tony

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Mark Wright

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