When I'm driving along in my 27 my Motometer is under the eye. When I shut the car off the Motometer spikes imeadiaty. A previous owner installed a water pump, (It will be removed this winter). I was wondering if the thermometer is touching the water while I'm driving or is the water pump drawing the level down and not touching the Motometer causing false readings. Also am I right in thinking that the thermometer should be touching the water?
Thx. Brett

The moto meter is actually a steam gauge and not designed to be submerged for an accurate reading.

http://books.google.com/books?id=8swqAAAAMAAJ&pg=PA1298&lpg=PA1298&dq=moto+meter +spark+plugs&source=bl&ots=T1WtcDfNmE&sig=ZRxH461JORAg2ufexLkcm7OKhCk&hl=en&ei=f m47TNKQMYO88gaOs8GmBg&sa=X&oi=book_result&ct=result&resnum=13&ved=0CE0Q6AEwDA#v= onepage&q&f=false

Motometer does not need to touch the water. The air temperature inside the radiator is within a few degrees of the water temp.
The spiking is also normal. While the engine is running, cooled water flows through the block taking a portion of the blocks heat with it. The over-all temp of the water achieves a fluctuating "happy-point" of temperature. When you shut the engine off, the flow slows down, but continues some because the thermosiphon continues, although at a reduced rate due to the restriction offered by your water pump and the reduction of air flow through the radiator. The result of this, is that the heat still in the block keeps heating the water. And the now heated hotter water goes to the top (in the radiator nearest the Motometer), and stays there while it slowly cools by slow air flow. Unless the wind is blowing, that may be mostly it's own heat rising outside the radiator.
By the way. I use a water pump. I do like them. Sorry Royce et al.
Drive safely, W2

John read and typed faster.
Some day, maybe I will tell the story of the only water pump that ever gave me any real trouble.
W2

Overheat after shutdown can also indicate retarded timing, which is also indicated by the running temp being so high.

I run 180 thermostat and waterpump, and rarely see red at all, except when idling, as I don't run a fan.

rdr

Brett, Wayne gave a very detailed discription of whats happening when you shut your engine off. I would like to add if you are running below the circle, you're probably running a little cool.

The gauge design was actually quite ingenious because they could use standard lengths of the temperature probe instead of trying to accommodate all the different depths of radiator tanks, necks etc. which would be required of a probe needing to be submerged in the coolant. Here is an example of a British design calor meter that is designed to run in the coolant. I would imagine there would be certain cars with short necks, shallow tanks, or vice-versa that this design would not work with.

John : It looks to me,that meter is from an Fordson E 27 N Tractor
Toon

Anthonie, It probably was for a tractor or truck. I thought It would look great on my old truck. It was an eBay item from the UK. It sold for nearly 300 dollars. More than I could afford but I owned it for a little while.

John, I tried to email you, but it bounced back. Send me a message. dstroudch47ce@hotmail.com Sorry about the thread drift. Dave

When you stop driving there is no more water circulation or air movement. Naturally the warmer water in the engine will continue to affect the rest of the water in the system. It is normal to see the mercury climb in the moto meter for a while after you stop.

If you get rid of the water pump there will be little difference in the operating temperature, but your car will be more reliable and will have fewer leaks.

Dead on Royce!!!