Caterpillar C-18 1150hp Temerature Range

[intouch1]

Caterpillar C-18 Acert 1150 hp

Am having a question concerning my engines. Kindly bear in mind boat is located in Red Sea, with elevated ambient and sea water temperatures.

In winter, both engines would run at 90 degrees centigrade at any rpm. Beginning of summer I started noticing temp ranges in the 95 degree range. Both engines exhibit same behaviour with a nominal difference of maybe 1 degree.
On my last cruise a few days ago, the engines would sit at 95 degress at 1750 rpm. Opening her up to 1800 would evelvate temps to 97. Upon reaching 98 degrees at 1830 rpm and reduced throttle to get temp down.

If idled, temperature goes down to 81 degress in a matter of a few minutes.

Boat has only 100 hours and the impellers look fine so does the discharged cooling water.

The Manual of my Engines states the coolant temperature warning at 103 degrees centigrade but states no operating range.

I spoke to CAT Concierge, and they said if no alarms it is fine to operate the engine at whatever Speeds that do not set off the alarms.

Today I asked my captain to do a Trial while keeping the engine hatch open from start. Maximumtemp reachet at 1800 rpm was 93 on one engine and 96 on the other. Upon idling both engines quickly settled at 81 again.

My gut Feeling tells me engines should be running in 90-92 degree range at all rpm ranges. 96-98 seems very high to me. However, i would then assume that Alarm would be programmed to set off lower too ??

All Input greatly appreciated.

 

[jfm]

The thermostat wants 80-81 degrees, so in your case the thermostat is just wide open and the 90-something temperatures you are seeing are the best the heat exchanger can deliver. It must be caused by your warm sea water temps combined with on-the-limit heat exchanger design - my Cats sit at 80degrees even at 90% load, but sea temps are "only" 27-28 degrees max.

The only way to get back to 80 degrees is bigger heat exchanger/bigger seawater flow, but that requires major surgery

I'd be interested in Latestarter's opinion about running the engines at 95 degree jacket water temp, long term

 

[intouch1]

thanks, jfm....that's what Cat Concierge implied if I Keep seeing These temps....larger heat exchangers would be required.

The question is how safe is it to run at These temps if for 30% of yearly running time.

 

[jfm]

The question is how safe is it to run at These temps if for 30% of yearly running time.

Exactly! I would be interested to hear LateStarter's and Tinkicker's views on that question

Also you might want to ask the Cat guys if they have an off-the-shelf bigger heat exchanger for "tropical" use, because that will be easier than designing/making from scratch

 

[jrudge]

I have C18 1150 engines also.

The Fairline manual says two conflicting things!


In the CAT section

temperature gauges
At both helm positions, the temperature gauges are the two highest instruments in the pattern of five small round dials between the tachometers. They show the engine coolant temperature.
Normal operating temperature: 82°C - 103°C

in the Instrumentation Section

temperature gauges
Temperature gauges are the two highest instruments in the pattern of five small round dials between the tachometers. They show the engine coolant temperature.
Caterpillar engines 86°-89°C (briefly to 99°C)

You are seeing 95 degrees, which is less than 103 and less and 99, but more than 89!

 

[intouch1]

I have C18 1150 engines also.

The Fairline manual says two conflicting things!


In the CAT section

temperature gauges
At both helm positions, the temperature gauges are the two highest instruments in the pattern of five small round dials between the tachometers. They show the engine coolant temperature.
Normal operating temperature: 82°C - 103°C

in the Instrumentation Section

temperature gauges
Temperature gauges are the two highest instruments in the pattern of five small round dials between the tachometers. They show the engine coolant temperature.
Caterpillar engines 86°-89°C (briefly to 99°C)

You are seeing 95 degrees, which is less than 103 and less and 99, but more than 89!

jrudge, the CAT C-18 Operators Manual says that coolant temp Alarm would kick in at 103. so the 86-89 of the failine Manual is wrong. the 82-103 in the fairline Manual seems correct to me.

 

[intouch1]

Exactly! I would be interested to hear LateStarter's and Tinkicker's views on that question

Also you might want to ask the Cat guys if they have an off-the-shelf bigger heat exchanger for "tropical" use, because that will be easier than designing/making from scratch

i believe they have a Standard larger heat exchanger from what i understood. CAT Concierge did not seem to mention it would be too much of an issue.

 

[Latestarter1]

Caterpillar C-18 Acert 1150 hp

Am having a question concerning my engines. Kindly bear in mind boat is located in Red Sea, with elevated ambient and sea water temperatures.

In winter, both engines would run at 90 degrees centigrade at any rpm. Beginning of summer I started noticing temp ranges in the 95 degree range. Both engines exhibit same behaviour with a nominal difference of maybe 1 degree.
On my last cruise a few days ago, the engines would sit at 95 degress at 1750 rpm. Opening her up to 1800 would evelvate temps to 97. Upon reaching 98 degrees at 1830 rpm and reduced throttle to get temp down.

If idled, temperature goes down to 81 degress in a matter of a few minutes.

Boat has only 100 hours and the impellers look fine so does the discharged cooling water.

The Manual of my Engines states the coolant temperature warning at 103 degrees centigrade but states no operating range.

I spoke to CAT Concierge, and they said if no alarms it is fine to operate the engine at whatever Speeds that do not set off the alarms.

Today I asked my captain to do a Trial while keeping the engine hatch open from start. Maximumtemp reachet at 1800 rpm was 93 on one engine and 96 on the other. Upon idling both engines quickly settled at 81 again.

My gut Feeling tells me engines should be running in 90-92 degree range at all rpm ranges. 96-98 seems very high to me. However, i would then assume that Alarm would be programmed to set off lower too ??

All Input greatly appreciated.

Just so happens had a Cat industrial tec on the line....

Not sure if engine protection on Cat marine engines is enabled, but on industrial C18's thermostat modulating range is 86 to 89 degrees C, de-rate protection is enabled at 101 degrees with shutdown at 103 degrees C. Your gut feelings are correct, my tec says far too close to 101 degrees.

Will do some more digging.

 

[intouch1]

Just so happens had a Cat industrial tec on the line....

Not sure if engine protection on Cat marine engines is enabled, but on industrial C18's thermostat modulating range is 86 to 89 degrees C, de-rate protection is enabled at 101 degrees with shutdown at 103 degrees C. Your gut feelings are correct, my tec says far too close to 101 degrees.

Will do some more digging.

Latestarter1...thank you for your help....

on C-18 Acert Marine...temp Alarm goes off at 103 and after 30 sec at 103 it goes into reduced power mode.