no thermostat??force 85hp

gustafsonerik

Petty Officer 1st Class
Thread starter
Joined
Jun 25, 2006
Messages
238
can running your outboard without a thermo in it hurt anything??? other that not having the fuel mileage would it do any damage???
 

maxum247

Lieutenant
Joined
Sep 18, 2007
Messages
1,363
Re: no thermostat??force 85hp

It has been said that running without the thermostat isn't a good idea, may wharp the head due to uneven temperature's, better to run with the thermostat from what I can tell!
 

MWBROWN

Petty Officer 1st Class
Joined
Feb 7, 2006
Messages
231
Re: no thermostat??force 85hp

A thermostat does two things.
Keeps from overheating.
Keeps the engine at a constant temperature.

Put one in and it will run better, and your economy will return.
Not that a Force has economy :0.

Just like a car. Needs one to run properly.

Not that much money when you consider the alternative.

Mike
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: no thermostat??force 85hp

Well, if you are running the engine in the winter in 30 degree water, it is important to restrict water flow and thus keep the engine at optimal operating temperature.

If you are running in 70 degree water?

You need to understand the water flow path in these engines.

First, all water from the pump passes around the exhaust chest because without it exhaust gases would burn through. Then this same pre-warmed water passes around the cylinders and through the head. With a thermostat, the water is regulated to keep both the upper cylinder walls and head WATER at 160 degrees. This does not mean the head and walls are 160
Without a thermostat, full water flow cools the head and cylinder walls water below 160--how much? I never measured. How warm or cool would the head and walls themselves be? I never measured.

Although the pistons are machined oval to account for uneven heating and expansion, (they become circular at operating temperatures) they are primarily cooled by the fuel/air mix ingested into the crankcase--not by the cylinder walls and head. And there is no cooling below the ports. So only the combustion areas are cooled.

But just as an automobile engine will run quite happily and without harm with no thermostat, (of course, now the computer gets excited but in the old days, we didn't have them) so will the outboard. The net result may be slightly poorer fuel mileage--internal combustion engines do run better hotter (to a degree) but if you need to worry about that, you shouldn't be boating.

I truly doubt that a Force water pump could deliver enough water to cool the engine to a damaging point. I could be wrong though--Heaven knows--I got married, didn't I?
 
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