No thermostat?

Putting it back together, and noticed that the thermostat housing had no thermostat in it. I know I didn't take it out... wtf?

It usually ran 180-ish before I pulled it, but was down a cylinder and a half - #3 had no compression #5 had 40psi, all the rest were about 180psi.

Can you run a motor with no t-stat, and what are the benefits / problems of doing that? Should I put one in... maybe a 160*?

Without a t-stat the coolant will not stay in the radiator long enough for the cooling fan to do its job it will just circulate and never be cooled properly. If the thermostat doesnt open fast enough the coolant will stay in the engine too long and get too hot, and once the stat does open the cooling fan will not be able to keep up with the extra temp, so it will send improperly cooled coolant back into a block thats already too hot.

I would run a 180, a 160 will stay open all the time during hotter days, wich will again cause the coolant to not effectivly be cooled by the fan.

You really need to use a thermostat for the reasons above. If it doesn't get real hot where you are you can run a 195*, a hotter engine is more efficent, but not too hot.

Thanks guys.