Ford Lehman 120 normally operating temps??

[Bigfish]

It's hot water here in the Keys but port engine seems to be running hotter after valve adjustment... 180 degrees okay??

Thanks

 

[rslifkin]

Not sure about the Lehman specifically, but 180 doesn't strike me as concerning for any engine with heat exchanger cooling and a pressurized cooling system. Some don't like to get much hotter than that though.

 

[READY]

180 sounds very nominal to me. If you were seeing something much lower prior I wonder if the thermostat was changed?

 

[SteveK]

It's hot water here in the Keys but port engine seems to be running hotter after valve adjustment... 180 degrees okay??

Thanks

180* should be OK.

Manual says operating range is 175-190*F
then goes on to say Optimum temp 195*F

The latter does not make sense to me.

 

[Capt Jack]

Mine runs 180 this time of year. Winter in southwest Florida it is a tad bit less but never under 175 under load

John

 

[alormaria]

180 is normal for me.

 

[Bigfish]

Thanks!

 

[SoWhat]

250 is not OK. 180 is OK. Calibrate your gauge with an IR gun.

https://www.amazon.com/Etekcity-Las...keywords=IR+thermometer&qid=1631156690&sr=8-3

 

[BruceK]

180 is ok, but has something changed. What was the operating temp before this? When something like engine operating temperature changes, check for something going amiss. It needs investigating.

 

[jleonard]

Mine always ran 180 at the helm gages, and 170+ according to the manual gage that was off the expansion tank in the engine room.
If I pushed it up to WOT it would slowly climb to 195 and hold there.

 

[Capitaine R]

How much of a valve adjustment was needed? If they were way to loose and now the engine is running more efficiently that could explain the increase. I think I would check the valves one more time, just to make sure.

 

[Marco Flamingo]

My prior owner had a 170F thermostat with a hole drilled in it. The hole is some kind of hack to make sure no air gets trapped behind the thermostat. Kind of an old wife's tale. The result was that the engine would literally take an hour to warm up. Any speed below 1500 rpm would drop the temp down below 170. Hot water from the engine took hours and wasn't that hot. The Red Dot "bus" heater was anemic.

I replaced with a 180F thermostat. Couldn't find a 190F. Now it goes quickly to 180 and stays even at WOT. Don't pay $30 because the seller lists it as an official Ford Lehman marine thermostat. Ford Mustang cap will work at 1/3 the price. Just needs to be 4# pressure.

 

[catalinajack]

My prior owner had a 170F thermostat with a hole drilled in it. The hole is some kind of hack to make sure no air gets trapped behind the thermostat. Kind of an old wife's tale. The result was that the engine would literally take an hour to warm up. Any speed below 1500 rpm would drop the temp down below 170. Hot water from the engine took hours and wasn't that hot. The Red Dot "bus" heater was anemic.

I replaced with a 180F thermostat. Couldn't find a 190F. Now it goes quickly to 180 and stays even at WOT. Don't pay $30 because the seller lists it as an official Ford Lehman marine thermostat. Ford Mustang cap will work at 1/3 the price. Just needs to be 4# pressure.

No, Marco, it is not an old wives tale. Some thermostats come with that hole from the manufacturer. The hole is there to allow air to move. No way that a 1/8 inch hole is large enough to prevent an engine from warming up in a reasonable amount of time. OEM Lehman thermostats have that hole. My Lehmans warm up to operating temp in 10 minutes at 1,500 RPM.

You replaced the thermostat. Could it have been that the old one was hanging open? That it was faulty? That that was the cause of long warm ups? Methinks so.

 

[rslifkin]

A 1/8 hole has noticeably slowed warmup on some engines I've seen. 1/16 is plenty to bleed air with no noticeable effects otherwise.

 

[Comodave]

Our last boat had Lehmans in it. One engine ran at 175 and one at 180.

 

[FF]

Any thermostat can be observed working in a pot of water on the stove and a thermometer.

 

[Bryant]

Fl 120 temps

it's hot water here in the keys but port engine seems to be running hotter after valve adjustment... 180 degrees okay??

Thanks

180 is right

 

[Mobcat]

Mine runs around the 180 mark, and while where on the subject mine always seems to need coolant after a long trip , never runs hot but always takes about 2 LT of coolant , seems to always be the same amount I think if I didn’t refill to the top it would be fine, maybe the tank needs 2lt expansion area I’m not sure but it dosent come out in the overflow ?????? Strange hey ?

 

[Lepke]

Most diesels run more efficiently at higher temp up to about 210°F. It atomizes the fuel better and makes a better burn. I changed my diesel PU to run at 205° and gained 2mpg when running light. Later I found out it was designed to run at that temp, but the OEM decided 180° would cause fewer overheat problems in hot climates so changed all the thermostats.

 

[SteveK]

Mine runs around the 180 mark, and while where on the subject mine always seems to need coolant after a long trip , never runs hot but always takes about 2 LT of coolant , seems to always be the same amount I think if I didn’t refill to the top it would be fine, maybe the tank needs 2lt expansion area I’m not sure but it dosent come out in the overflow ?????? Strange hey ?

Not at all. I was losing about the same until I replace the main heat exchanger

 

[David Burgess]

Most diesels run more efficiently at higher temp up to about 210°F. It atomizes the fuel better and makes a better burn. I changed my diesel PU to run at 205° and gained 2mpg when running light. Later I found out it was designed to run at that temp, but the OEM decided 180° would cause fewer overheat problems in hot climates so changed all the thermostats.

Your completely correct about Diesel temperatures
All Diesels prefer a higher temp Not a lower , cold temperature such as our friend has described, I would strongly recommend installing 190deg thermostats for improvement in both fuel efficiency and overall performance as well as engine longevity. Don’t forget to Normalize your engines Before shutting them down.

 

[rslifkin]

In general, all engines want hotter coolant, colder air and colder fuel. At least up to the point where higher coolant temps start to cause issues (detonation in gas engines, short gasket life, high oil temps, and other concerns in all engines).

 

[ronobrien]

250 is not OK. 180 is OK. Calibrate your gauge with an IR gun.

https://www.amazon.com/Etekcity-Las...keywords=IR+thermometer&qid=1631156690&sr=8-3

Also calibrate the IR gun. The cheap ones are ok for finding discrepancies but not so much for accuracy. I checked mine at low temp with a glass of ice water. The difference was over 10%