440 over heating problem

[Kevin71]

440 over heats now that I have put on a classic air conditioning.  I did this when I had the engine out of the car for painting.  At that time one of the freeze plugs had been leaking a little bit.  So I changed all of them.  When I pulled out the old freeze plugs there was alot of build up in the water cavity.  Some of if broke off so I removed what I could get too.  Since I put it back together it overheats now when never had before.  It has a new aluminmum water housing and pump.  OEM fan, fan shroud, and a 4 core champion aluminmum radiator.  New 180' thermostat that I check with a thermoter to be working correctly.  I am now thinking this build must have broke loose some small parts that is clogging the water passages.  My son suggested that maybe it leaked before and someone put a bunch of stop leak in it.  Anyway could this be what is causing it to over heat.  I thought about trying some of the radiator flush out but I am affraid it might make worse or clog the radiator.  Water is flowing thru the raditor and increases speed when the motor revs.  At this point I am thinking I am going to have to tear it down and acid deep the block which was not done the last time someone rebuilt it right before I bought the car.

[MEK-Dangerfield]

You have also added a new water pump into the equation. Do you know how many blades it has?

Is this the radiator you used before?

[Jesus H Chrysler]

My 440 is a 75 vintage C-body unit out of an Imperial that has about 70-80k on it.  I used an original 340 3 core 26" radiator because the lower pickups matched the C-body water pump housing.  It overheated whenever I put any stress to the engine.  I decided to upgrade the whole cooling system and got pretty much the same stuff you got.  Mopar aluminum housing, aluminum pump, 180 stat and a new aluminum radiator.  When I pulled the old water pump housing off a TON of sludge and brown coolant came out.  I had no idea the engine was that bad.  I got a big tray and a hose and power flushed the block through each water pump port.  POUNDS of sludge, sediment and brown coolant came out.  I flushed for quite some time along with using a coat hanger to dig out some chunks.  Once the water ran clear I re assembled all the new parts, clean fresh antifreeze mix and purged the air bubbles.  Since then the temp gauge NEVER goes over 180.  No matter what I do, it refuses to overheat.  Maybe it's worth pulling everything off again and power flushing the block?  Unless it was a recent rebuild you may have a ton of sludge and rust yourself.  That will just circulate and clog up the new radiator.

[72rtchallenger]

My 440 is a 75 vintage C-body unit out of an Imperial that has about 70-80k on it.  I used an original 340 3 core 26" radiator because the lower pickups matched the C-body water pump housing.  It overheated whenever I put any stress to the engine.  I decided to upgrade the whole cooling system and got pretty much the same stuff you got.  Mopar aluminum housing, aluminum pump, 180 stat and a new aluminum radiator.  When I pulled the old water pump housing off a TON of sludge and brown coolant came out.  I had no idea the engine was that bad.  I got a big tray and a hose and power flushed the block through each water pump port.  POUNDS of sludge, sediment and brown coolant came out.  I flushed for quite some time along with using a coat hanger to dig out some chunks.  Once the water ran clear I re assembled all the new parts, clean fresh antifreeze mix and purged the air bubbles.  Since then the temp gauge NEVER goes over 180.  No matter what I do, it refuses to overheat.  Maybe it's worth pulling everything off again and power flushing the block?  Unless it was a recent rebuild you may have a ton of sludge and rust yourself.  That will just circulate and clog up the new radiator.

this is what i would do

[Cooter]

My experience has been that some BB 440's just run hotter than others...I got THREE on the road and out of the three, the 1974 Engine runs coolest @180 degrees. The 1970 Fully machined and bored .030 with stroker crank and iron heads, runs anywhere from 180 on a COLD day, to 230 and up on a 90 degree day...
The other one is a 1966 440 that is STOCK as a rock on the bottom end, with closed chamber heads, runs anywhere from 200-220 Degrees all the time..

ALL THREE HAVE Fan shrouds, clutch type fans, two have up and down Chrysler radiators(The one that runs coolest is running one of these), and one has aluminum cross flow all new, 180 Degree T-Stats...Now you tell me why the hell the other two heat when the one doesn't?

[GreenFish]

this is what i would do

x2

[Kevin71]

The water pump is a high volume from 440 source.  The coolant has always been green with no discoloration.  Should I try a chemical cleaner.  Like a radiator flush .  Do you think this would dissolve the build up and break down any that might be clogging the system.  And how hot is to hot.  It doesn't seem to go over a 240 even with the ac running on a 90 degree day.  But it will soon be hitting 98-99 degrees with high humidity here in florida.  It just never over heated before all this was done is what is confussing to me.  One suggestion was to pull the bottom radiator hose and the top one loose.  Then run a garden hose in the bottom hose to back flush the system.  I think the first chance I get I will at least try this.  I just affraid that if I use some sort of radiator cleaner it might cause the new radiator and heater core to clog.

[Chryco Psycho]

is the fan on the right way around , is the carb too lean , is the timing adavnced enough , are you using a 180 T stat , is you vacuum advance connected to manifold vacuum , it should not be , any of these can can cause overheating

[Kevin71]

Well I had shop dyno tune the motor.  The fan is correct the thermostate is a 180 and opens at 180.  Checked it on the stove.  The timing was advanced so far the motor was dragging trying to start, also ran rough.  I back the timing off a little and it runs much smoother and cranks fine.   It was over heating before that change.  But the timing is set at about 36' degrees bftd.  Could maybe the advance timing isn't coming in soon enough?  I am not sure how to check that, but I think there was a thread on it. 

[HP2]

I agree that fllushing the block may help you out, but if it never ran hot before, they may not be the answer.

Is it hot all the time or only under particular circumstances, ie only running the a/c, only in traffic, only on the highway, etc? If hot with the a/c, you may have a combination of air and coolant flow. The a/c condenser is dumping heat right in front of the radiator so you might need more air and more coolant flow to improve. If hot in traffic, you need more air flow. If hot on the highway, a change in coolent flow is required.

Something almost everyone overlooks is pulley ratios. There are a variety of different sized water pump pulleys that are varied in size from small to large. Heck, even some crank pulleys differ in diameter. If you put a/c on a non a/c car without a change in water pumps ( number and size of impellers) and without a change in pulleys (diameter to spin the pump faster or slower) you could be setting yourself up for a hotter running engine.

Two things can happen with pulley ratios; you spin it too fast and the water doesn't have a chance to absorb the heat, or you spin it too slow and the water absorbs too much heat. See what size pulley you have now. Maybe go to the pick a part and pick up a different sized one and see if that helps. This is when fancy underdriven performance pulleys can actually be a hinderence.

[Cooter]

4 row/core radiators are NOT the way to go as by the time the air gets to the last core, it is already so hot it isn't doind anything to the last core anyway...A/C condensors in front of the radiator WILL CAUSE A SLIGHT increase in the temp, as the freon turns to a gas and back to a liquid, it does this by "Condensing", ie: the condensor in front of the radiator gets HOT..Therefore, it needs to be mounted out front in order to cool the freon back down to a liquid...This is why all A/C cars got the heavy duty cooling systems from the factory..

[Jesus H Chrysler]

   Also check to make sure the fins on both the radiator and condenser are not bent.  You should be able to see daylight through both.  If fins are bent that blocks airflow and pretty much negates that section of the radiator.

[Kevin71]

Here goes.  The car overheats when driving around a neighborhood. Taking off running slow after about 45 minutes with no ac on.  But then drove down the hwy and it didn't cool down at all.  Even ran the heater didn't do any good.  Carb has had no jet changes, just adjusted idle when it was dyno'd.  After this overheating I decided to check the timing as when it was dyno'd it was advanced further than it was previously.  I ran the rpm's up to 2500 and set the timing to 36' BTDC.  Drove the car after about 20 min it heats back up, however the engine ran much smoother and cranked easier.  It was dragging when cranking before.  The motor was pulled when painted and ac added.  New 4 core radiator added over flow tank.  New aluminmum water pump housing and hi flow pump from 440 source installed. New 180' theromstate and verified it worked at 180 with a laser thermometer.  Verified that the gauge matched the water temp with the laser thermometer.  All new accessory brackets and pulleys for ac installed.  Pulleys ordered for a ac motor.  No fins are bent anywhere.  The temp ran around 160- 170 this past winter with outside temps in the 40-50's and never over heated.  Even running pretty hard.

[Cooter]

What is considered "hot" to YOU? I mean, 200-220 degrees is NOT running hot by todays standards, besides, at SEA LEVEL, 200 degrees isn't hot, but different atmospheric pressures will effect temps...If it isn't boiling coolant out into the overflow, or on the ground, I would say it is NOT overheating, even though YOU feel better seeing that temp gauge at 180 degrees...

[Strawdawg]

is the fan clutch good?

As pointed out above, four row radiators are not very good.  Often they have high fin count which tends to block air flow and sticking a condensor in front of it blocks even more.  Add the smaller tubes, and that does not help either.