Civic doesn't warm up.

[Barefoot]

it would be fine, you just wont have any heat.
-your heat runs off anti-freeze, if you run without thermostat than your coolant will keep rotating causing it to cool down very fast. even with thermostat or not, the BIG cooling radiator will cool it down too much also witch will cause no heat in your vents.
-theres different heat, your block has its own heat, the engine will be fine unless your planning to head way up north without a thermostat, it's temperature will stay hot enough to function.

one way of having heat with a BIG radiator is by covering haft the front of your radiator with a pice of cardboard.
but check first if your thermostat is stuck or not. prob not if you run anti-freeze and not water.

wtf worst piece of advice ive seen awhile.

[Halfwit]

wtf worst piece of advice ive seen awhile.

its not that un-useful. i was lazy and had a trash bag covering my radiator every morning (45 min drive in the cooold) cause therm was bad, and it worked great. car warmed up to where it normally should, and i had heat. i did this for 3 months. but i do agree in just changing it.

[Grimm Reeper]

wtf worst piece of advice ive seen awhile.

el oh fawk'n el right there sir


but I've seen worst

[WRX STi]

Not to mention that your gas mileage will suffer by not running at operating at full temperature. The hotter the engine is, the better the gas mileage, eg. a 195 degree thermostat will give you slightly better gas mileage than a 185 degree thermostat.