: Just rebuilt my 225 (All stock) in my 68 Dart.
: Engine is running fine now except it wants
: to run hot. Had the stock 2 row radiator
: recored, new water pump and hoses, 160
: Thermostat, 16lb cap, and running the stock
: 4 blade fan. The 68 Darts /6 didn't have a
: shroud. Non A/C car with A/T.

: Drain the radiator down to where you can get a
: look at the top of the core tubes. (a small
: flashlight helps)
: Check to see if there is any "rust
: scale" or other junk plugging the core
: tubes.
: New (rebuilt) engines can have a lot of loose
: rust scale in the water jackets which can
: quickly plug a radiator.
: The good news is that this stuff can be
: "back-flushed" out if you catch it
: quickly.
: You may want to varify the actual water temp.
: to the gauge reading by using a cooking
: thermometer.
: Other things to check is the timming (retarded)
: and the heat riser valve / exhaust system
: for restriction.
: DD

: Doc,
: Block and head were cleaned very well and were
: washed and flushed a number of times before
: freeze plugs were installed and engine
: assembled. Also, I removed the block drain
: plug and flushed it and the radiator again
: and haven't seen any rust or scale. Don't
: see any on top of radiator tubes.
: Timing is exactly on TDC.
: There have been some suggestions to go from the
: 160 to a 195 thermostat.
: What do you recommend? A 160, 180 or 195
: thermostat.
: I checked it with a liquid thermometer and
: removed it when it reached 200 degrees which
: was the max for the thermometer I had. What
: should be the normal operating temp for a
: stock 225 (non A/C with A/T)? The outside
: temp is pushing 100 degrees.
: It has never boiled or blown steam but gets
: VERY hot. Idling temp and driving temp seems
: to be the same - at least by the guage.

: Great job on the block / head pre-cleaning,
: this is ofen overlooked and a cause of
: overheating problems.
:
: Al's suggestion to try a different thermostat
: is a good one, thermostats are inexpensive
: and easy to change so try a different one.
: (or two)
:
: One thing you may want to do / check is to test
: the circulation. Run the engine without a
: thermostat to see how aggressively it moves
: the coolent. (watch the water run thru the
: top tank)
: I have seen some water pump impellers and
: seperator plate combos that were not real
: efficient. (the impeller was installed far
: away from the plate opening and / or the
: plate opening was small)
:
: I would say to bump-up the timing to 6 degrees
: BTDC to see if that helps. Another thought
: is that this new engine is a little tight
: and is producing extra heat through added
: friction, in my mind, the cooling system
: should be able to handle that.
: DD

: One thing you may want to do / check is to test
: the circulation. Run the engine without a
: thermostat to see how aggressively it moves
: the coolent. (watch the water run thru the
: top tank)
: I have seen some water pump impellers and
: seperator plate combos that were not real
: efficient. (the impeller was installed far
: away from the plate opening and / or the
: plate opening was small)

: given the direction that my engine turns
: (clockwise viewed from the front), my new
: water pump's impellers "slap" the
: water with their flat side rather than
: "scoop" the water with their
: cupped side. I don't have an old one to
: compare it with. Is this a concern,I can't
: find any that are the other way.