Running cold for 10 years

[Emmalina]

Just overhauled my cooling system on a Perkins 6354 and found the sender unit for the temp was not the correct one and in the wrong place. Ordered the correct sender unit and watched the temp climb to an astounding 105F . Checked this with a infra red thermometer and yes it is correct. The old sender was tapped into an inspection plate at the rear of the engine. The original bolts straight into the head at the front. I have never really checked the temp before as with the old sender it was always 180F ... I now think I know why it never had a thermostat fitted . Time to fit the thermostat me thinks....

[Compass790]

I'll be interested to know what (if any) difference you notice.
Our engine has been running too cold for over 40 years as it's raw water cooled.Certainly better to have a thermostat.

[Emmalina]

Originally Posted by Compass790

I'll be interested to know what (if any) difference you notice.
Our engine has been running too cold for over 40 years as it's raw water cooled.Certainly better to have a thermostat.

Thought even the raw water ones had a thermostat !

[tkeithlu]

Were you getting smoke from unburned fuel?

I think I'd confirm the new temperature with your infrared thermometer as well...

Speaks well of the Perkins engine that it never complained.

[Bill O]

Originally Posted by Emmalina

Just overhauled my cooling system on a Perkins 6354 and found the sender unit for the temp was not the correct one and in the wrong place. Ordered the correct sender unit and watched the temp climb to an astounding 105F . Checked this with a infra red thermometer and yes it is correct. The old sender was tapped into an inspection plate at the rear of the engine. The original bolts straight into the head at the front. I have never really checked the temp before as with the old sender it was always 180F ... I now think I know why it never had a thermostat fitted . Time to fit the thermostat me thinks....

I'm not certain about the 6.354 head, but the 4.236 head has several places to put the temp sender. The hotter temps will be in the front of the motor while placing the temp sender in the rear will be lower.

A temp of 180F for a Perkins doesn't seem off, while 105F while running for a while in gear seems extremely low. If it is correct, you should have a thermostat in place.

Like the 4.236 you should have a choice of thermostats available from Perkins. One should be a 180F and the other ~165F.

[fox9988]

Originally Posted by Emmalina

Thought even the raw water ones had a thermostat !

My Universal 5411 does. 143F

[Bill O]

Emmalina,
Looked a little further into the 6.354 and depending if you have the bowman w/the manicooler you may have 2 thermostats. https://www.trawlerforum.com/forums/...tat-45510.html

Which version of the 6.354 do you have?

[Puget Dan]

Our lugger 50hp has a thermostat on the radiator cooling system but not on the raw water cooling system. The lugger is 23 years old and has run well all these years with regular maintenance.

[Madehn]

My 6.354 runs at a consistent 180 degrees. Cant remember where the temp sensor is but i doubt that anywhere is 105 degrees after any time running it- It should be measuring your fresh water portion of the system which should be reasonable uniform- i would not expect a large difference ( more than 20 degrees) between front and rear- put a thermostat in and see what you get.

[Compass790]

Originally Posted by Emmalina

Thought even the raw water ones had a thermostat !

Yea they sure do but ours opens at 52oC or 125oF
What I was getting at is they seem to survive running at low temps. I did think of converting to fresh water cooling but couldnt be bothered when it survived so long before its rebuild at about the 37 year mark.
Oil temp never rises above 60oC which scares me a bit as I wonder if it's enough to evaporate moisture buildup but it must be okish as there is no rust internally.

[Emmalina]

Originally Posted by Bill O

Emmalina,
Looked a little further into the 6.354 and depending if you have the bowman w/the manicooler you may have 2 thermostats. https://www.trawlerforum.com/forums/...tat-45510.html

Which version of the 6.354 do you have?

I have the manicooler running on fresh water and its supposed to make it run hotter ! Not the bowman the original one.

[jimbunyard]

If I remember correctly, the temperature of raw water cooled engines is limited to about 160F or lower to keep the cast iron from which the engine is mostly made from absorbing salt and other minerals into the metal's pores, leading to it's early demise...

[Island Time O25]

My 40 year old Universal 5432 is happy between 130 and 160 when running at mid range. When revving up such as fighting current or head wind or some such it can go up to 190 without a care. Higher and it gets the salt build up at the mixing elbow, which it doesn't like obviously.