no thermostat in motor
 

i bought this truck, 78 f150 4x4 with a 351m in it. i went to replace the thermostat, just normal matenience, and there was none there. would this have done any damage to the motor while it was not in there??? i was just making sure while i was replacing parts on the motor. thanks

I doubt it did any damage but I would be checking to make sure the radiator is in good condition. The previous owner may have had some issues with it getting hot and tried to solve them by removing the stat.

oh ok ill try that. when i took out my radiator and was running water through it, it was really clear, and the fluid has always been a good color. when they say to mix the antifreeze with distilled water, how different is that than filtered water, out of a waterfilter like in the refrigerator for drinking, because i dont want to go to town to get some water when i could use mine??? thanks.

I'm not sure how clean the water is out of a waterfilter. Most of those just remove bacteria and maybe some lime. Distilled water is cleaned of all the lime and that is what is important. A waterfilter makes it taste good to you. Distilled water taste great for your system.

what will no thermostat in a motor do, besides no heat for the heater during the winter. because while i am looking for the right thermostat for my 351m i am going to hafta run it without one at all. thanks.

It will take it longer to warm up in winter. Which means more gas through the carb.

You will be fine to run it without a stat for now.

Low temp or no thermostat engine wear:
===================================

There is a chemical reaction that occurs at temperatures below 180F water jacket
temp. It is a reaction that forms chemicals (acids) that etch the cylinder
walls. Above 180F the combustion process reaches the cylinder walls and reduces
the fuel to normal combustion products so the acids do not form. Because of the
granular construction of cast iron the acids eat at the material in between the
metal grains faster than the base metal. The granules of metal come loose and
act just like microscopic metal "grit" inside the engine. The grit of course
scrapes away at the cylinder wall itself and rips off more grit. The grit gets
into the oil and grinds into the rest of the bearings, lifter bores, lifters,
cam, and valvetrain. When these components are ground and blasted by the grit
they produce more grit particles... The filter only removes a certain % of the
larger particles with every pass of the oil thru the engine. With large numbers
of particles being produced the filter's capacity to remove the grit is
compromised and rapid wear is produced.

The organic acids produced also collect in the oil and erode all of the metal
surfaces in the engine. Liquid water is not required for this reaction, just a
few water molecules, which are everywhere, is enough. Burning fuel produces
water vapor (water molecules).

Lower temperatures also produce more fuel "washdown" effects that remove
lubricating oil molecules from surfaces.

Cold pistons do produce more impact wear (piston slap) on the cylinder walls and
skirts. This can also lead to fractures in the piston skirt.


Ford 351M/400 Thermostat Info
==================
While your messing around with your thermostat keep something very important in
mind, make sure you use the correct thermostat. Most auto parts stores I've ever
delt with don't realize the difference in the correct and wrong unit. You will
notice on your engine that there is no heater bypass hose off the water pump.
That is because one of Ford's better ideas was to make the bypass system
internal in these engines. When the engine is cold the bypass is open and
coolant doesn't flow at full capacity around #7&8 cylinders. This lets you get
heat in the winter real fast as the heater takes it's feed from coolant
returning from those cylinders. When the thermostat opens it closes the bypass
and coolant is then forced by the rear cylinders. When you look at your
thermostat there must be a ring attached to the plunger(reminds me of the rim on
an old top hat). This closes off the hole in the block directly below the
thermostat. If the ring is not present then the bypass will not be closed and
those rear cylinders will run hot all the time.

An easy way to check the condition of your radiator is to place your hand on the surface after the engine is at operating temp. It should be nice and hot all over. If you have any cool spots you know water is not flowing in those areas.

ok that is what i was kinda thinking of.... my problem is no one around here knows what i am talking about. autozone said that they dont carry the cooper-robertshaw thermostat. even the napa store didnt know what i was talking about. does anyone know where i can get one of these thermostats online, or someone who can get them for me? because i am running out of resourses in town when even the parts stores leave me hangin..

Do not use tap water, filtered or otherwise in a radiator, unless in an emergency. It contains some dissolved salts (mostly hydro-carbonates) that will form deposits (scales) in the cooling system, reducing it's efficiency, or possibly clogging passages in an extreme case.

Auto-Zone had the Cooper-Standard-Robertshaw thermostats last I knew but you can call 248-596-5900 and ask who carries their thermostats now.

I know this isnt relevant to running without a thermostat, but....
If you use a copper thermostat you may be being less acidic, however I am not sure if the core of the system already includes copper. Can you keep the wear of your engine down to a minimum by a certain water additive as opposed to an oil additive.

I am always worried about additives that burn and create deposits and it seems the water additive with regular oil changes would be the best since the temp of the water is probably not as hot as the oil....or am I wrong?

Oh yeah, if so what would the water additive be?

There isn't really a "water additive" other than rust inhibitors in the coolant. Use a 50/50 mix of distilled water and antifreeze (you may need a higher ratio of antifreeze to water depending on your climate). A high quality "antifreeze" will have around 95% ethelyne glycol and 5% rust anhibitors; the label will say somewhere if it does. You should also flush the cooling system every couple years or so, depending on vehicle use.