I had an accident.
 

Well. Im at a loss of ideas. Im in the end of a complete engine rebuild. rotors seals everything. I took off that valve that right at the tip of the water jacket because it was getting in my way with the engine hoise(dont ask how its hard to explain). But anyway when i went to put it back on i was unscrewing the nut and it fell into the water jacket.. Would it be possible to try and fish it out with a magnet or do i have to waste more time and take the engine back apart? please help. i feel so stupid.... damn butterfingers :(

You could try and use a shop vac set for blow and blow air into the other end of the water jacket through the water pump passages...
Turn the engine on your engine stand so that the hole it went into faces down.
Try a magnet...

If you fail, then you've gotta pull the engine apart

You might get lucky.

My sympathies to you. I've had similar brainfarts.
+1 on blowing air through the other end of the water jacket. If you have access to an air compressor, that works better that a shop vac.

Sounds like you dropped a nut down the thermostat housing? You can remove that entire housing and pull it out.

Or if it's just in the water jacket, leave it.

Naw wasnt the thermostat. It was in the EGR hole. I just figured i would get a string magnet and jam it down there.

And btw Aaron, I wouldnt have been able to diagnose my RX7 without your pages. The thing was overheating in less than 10 minutes of run time. Thanks bro!

If it fell into the big hole, then there probably isn't a reason to worry. It will just end up sitting at the bottom of the middle iron. Though I would make all efforts to remove it before giving up. :)