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I think you will find that putting in the 180 degree thermostat or less, instead of the called for 195 degree thermo is the problem. Whats happening is the water is circulating to fast and is not be cooled. Use a 13 to 15 Lbs. Raditor cap.
Check all hoses, may have a soft one collapsing on you.
Not enough air movement, do you have any screens in front of radiator.
Blocked engine water ports
Bad timing
Radiator needs cleaning or new
Just some easy stuff to check
Check the heat riser valve operation just below the header on the right bank....if it sticks closed or does not open completely, you will generate a lot of extra heat and loose mileage.
You are correct about the 185 degree thermostat as the preferred range. I currently still have the original air cleaner which warns using only a 185 Degree P/N 3837609 Thermostat. Dodge tells me the number has been changed to 3512998 which you said your parts manual called for. The required thermostat pictured in the 78/79 Dodge Motor Home Chassis book is a balanced design hi-flow thermostat. Advantages of this type of design are fast response and increased coolant flows to the radiator, self cleaning design and unaffected by water pump pressure changes. The other pictured thermostat is the normal reverse poppet design. I also could not find the 185 degree replacement and did not want to pay $17.89 for the Dodge 3512998 thermostat. I found a Robertshaw Extra Performance PN 370-180 which is the correct design at Autozone for $4.99. The thermostat sits in the slight counterbore area as you mentioned and is sealed to the water outlet with a paperlike gasket. What is interesting though, is below the thermostat is a machined area in the block which is about 1/4 inch larger than the lower diameter of the thermostat and about 1/8 inch below the bottom. This machined area has a 1/8 high lip on the outside which would appear to hold a rubberlike gasket to seal this area to the thermostat. I don't understand why they would have machined this area instead of just leaving the original casting around the thermostat.
I have a 1980 leocraft with a 440 that would overheat in traffic jams my soulition was just simply turning on the heater but other than thatIt never overheats but the most important thing I do is after a long drive I never trun the motor off,I allow the motor to idol for five minutes to lower the overall temperture of the heads to cool down which prevents damaging the heads which is a common problem with 440 and most big block engines in motor homes and it also prevents the excessive temperture increase when trunning the off as soon as you stop.Good Luck
I have a 440-3 in my 1980 Leocraft motorhome. I followed some advise and replaced the thermostat to a 185 degree Robertshaw high performance stat as preventive maintance. I then had overheating at highway speeds. I checked the original and found it to be the Dodge motorhome thermostat. I put it back and had no further problems. I also installed a Stewart Warner temp. guage to give more accurate readings. Hope this helps
I've got an old Itasca motorhome with a Dodge 440 engine. When I bought it I couldn't drive it 20 miles at highway speed without having it seriously overheat on me, losing my antifreeze and seriously pissing me off. So I decided to declare war on the cooling system. I took the thermostat OUT, then I found some strong cooling system flush, which required pouring in an acid, running the engine at fast idle for 40 minutes, then draining the system and pouring in a powdered neutralizer, then again running the engine for 10 minutes and again flushing the system. When I put in the new antifreeze, I also put in a quart of a heat dissipating solution. This engine now barely registers off the cold mark on the heat gauge at highway speed, and I'll bet I didn't spend 20 dollars to fix it. Hope this info helps!
(engin turn but will not start)Coil is not geting current.wireing to coil is good.battery is goob.Problem start after replaceing transmission, engine never start after replacing transmission.ignition fuse is good
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