EGT temps?

[donald roth]

I put an EGT gauge on my 6bt cpl 2891 Cummins motor, and it works well, but I can’t find any guidelines as to what the readings should be.
I am seeing less than 400 deg at idle
600 at 1500 cruise
700 at 1600 cruise
Then a gradual rise to about 900 at wot, which is only for a few moments if at all.
Coolant temp is very stable at right around 180, cooling a little from there if idled for long, in or out of gear.
I’m wondering if this is in the ballpark for this motor, or is it too hot?
Thanks, Don

Topic

[Bill Desmarais]

Don,

I’ve had EGT senders and gauges on three of the five 6BTA 370s I’ve owned in two boats.

The twin 370s in my 31 Blackfin were propped to 3100 WOT which is under propped for the engines and that is good.
EGTs at cruise rpms averaged 825F-850F . These 370s had the factory 180F Tstats. The 31 Blackfin weighed in @ 16,000 lbs and
is a beast to push through the water.

My newest 370 is in a 25 foot lobster boat. This 370 has a SMX high flow 160F Tstat and is propped to 3200 rpm WOT.
The engine is purposely under propped quite a bit. Average EGTs at cruise and WOT rpms is 700F.

If I owned your engine/boat package I’d prop the engine to see no more than 800F-825 F under ANY conditions.

Just my opinion…keep us posted !

Regards, Bill D

[donald roth]

Guess I’ll have to get a boost gauge, install that, and pursue this later.
Thanks for the comeback.

[Corey Schmidt]

If you notice on the spec sheet there is a reference “All Data at Rated Conditions”

Engine Ratings:

Engine Model……………………………………………………………………………………………………………… 6BT5.9-M
Rating Type………………………………………………………………………………………………………………… Medium Continuous
Rated Engine Power ………………………………………………………………………………………. kW [HP] 134 (180)
Rated Engine Speed……………………………………………………………………………………………. RPM 2500

Exhaust Gas Temperature (Turbine Out)…………………………………………………………….. °C [°F] 405 (760) (** AT RATED RPM AND HP **)

What are your BOOST numbers at rated RPM?

[donald roth]

Thanks Rob, I had already located the spec sheet, but am looking to better interpret what little it says regarding EGT.
It says only “exhaust gas temperature at turbo outlet 760 deg.”
Should I assume that this means at high idle, under load, and that at 900deg, I am some 140 deg over spec?
What about at cruise speed, 1500-1600rpm where I am reading 600-700?
That’s where the motor spends 99.99% of its running time, and is my primary concern.
Thanks

[Rob Schepis]

EGT Spec

Attached is the curve with the EGT specs These sheets are all here on the website under the “Technical Information” tab.

[donald roth]

It will always be running light, as this is an ex-navy MUB rated to carry 150 passengers, and I don’t expect to load it anywhere near that!
The weight listed is 20,000 lbs, and I’ve added and subtracted here and there in converting the boat for my fishing/cruising use.
I would guess not over 25000 and I already added 2″ pitch to slow down the prop revs at cruise, which did not result in any temp changes, coolant or EGT.

[Rob Schepis]

Is that with the boat all loaded up as you plan to use it?
Or is this splash day when she’s running light?

[Author]

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