I know cooling issues have been beat to death here recently but here goes... the 383 in my 65 Satellite
was running 220 around town without much change on the highway. Had the radiator checked it was blocked so I had it recored. I switched the flex fan to a thermo fan clutch with a 6 blade fan, added a fan shroud, and a spring in the lower hose. I took it ou today and it still creeps up to 220 after about 10 miles driving around (not stop and go). Took it on the highway and it stayed up around 210. I'd love to go with an electric fan but that means a higher amp alternator which also means a bulkhead wiring bypass. Anyone have much success with the Milodon high flow water pump? I'm thinking of giving it a shot. Heard not so good things about FlowCooler. I have a 2500 stall converter in it and run the trans fluid through the radiator then to a big B&M cooler. Someone suggested bypassing the radiator and just using the external cooler. The car is never driven in anything close to cold weather.

Try backing the timing off about 2-3 degrees. What thermostat are you running?

I had a 180 in it. When I changed the rad and fan I decided to try a 165. After reading a lot of posts here, I see now that a lower temp stat won't help cooling. I bought the car with the motor done but I think whoever built it over cammed it. It sounds good, but with the stock tight converter it would die as soon as I dropped it in gear. That's why I swapped to a looser converter. I'm running about 18 initial and 36 total. I'll try backing it off a couple of degrees.

1969 RR 383HP stock eng (installed in a 67 satellite)
26in stock california A/C rad
spring in lower hose
160 high flow stat
flex fan
50/50 antifreeze
STOCK WATERPUMP HOUSING
milodon High Flow WP
Stock shroud

for me, the WP housing has changed everything, I had overheating issues with the newer aluminum WP housing (with the bottom opening not to factory spec) now I run 180 all day long in the Florida heat, any time, anywhere.

Had a 65 Sport Fury with a 383 that would get hot especially after an uphill run. Tried another radiator and fan, but my problem was a lot of crud in the block. Where you said your rad was blocked you may have the same problem. Take the drain plugs out of the sides of the block. If nothing comes out you probably will have to clean it out. I took out all of my freeze plugs and used a coat hanger to scrape the water jackets and a water hose to flush the block. After I did that it solved my problem.

I know cooling issues have been beat to death here recently but here goes..

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Understatement of the year .......overheating, or hot running coolant topics are usually good fodder for debates, or arguments,.......


seeing that you've chased after and rectified some of your cooling malidies, but are still experiencing hot running conditions,.....I experienced the same problem on my Charger Daytona, EVERYTHING was new, from the engine 440/6, to the entire cooling system, everything was properly installed and tuned/adjusted/set/etc....I was running a 5 row microtube radiator (26 inch) fan shroud, fixed factory 5 blade fan,......no amount of timing, playing with various spacers for the fan to create more pull thru the rad/shroud helped, no amount of playing with/without various thermostats helped with high temps 220+ cruisin around town,....open road or highway was fine, car would "cooldown" to 200,....no amount of water to coolant ratio helped either......

I finally stumpled apon an article on the Net,.....regarding the use of G-05 in Mopars...

I flushed the Prestone "green-freeze" out of the engine and cooling system,.....installed a 50/50 mix of water and ZEREX G-05 coolant (it's designed for cars running the "green" stuff) and I added a 8 oz. bottle of REDLINE WATER WETTER (from Autozone) as these were the product recommendations used,.....no other mods were done to the cooling system, but a mere coolant change, the results were 170-180 crusing temps, highway temps actually drop into 160,....190 is actually the hottest the car ever ran using the G-05 and waterwetter, and that was on a 100+ day idleing in stalled traffic during a Hotrod PowerTour,.....I've been running nothing but the Zerex brand G-05 and Redline Water Wetter in my cars, DailyDrivers and Toys, trucks, etc for the past 7 yrs with no issuses, the G-05 is clear in color, has no sticky residue, dosen't stain anything underhood, should you have a "spill" or "leak"......I had 2 other cars that were having hot running and "pukeing" problems,.....the G-05/Redline solved those issuses also, I won't ever "run" anything else coolant wise, after using the Zerex G-05/Redline


Mike

I agree you arent getting flow somewhere/I have a super cammed 440 in my 65.I run an OE never been touched 65 C body rad with the steel shroud.Flex fan MP aluminum wp and housing 180 stat.Even with 12.5 pistons it runs under 190 all day.The kids 62 300 with recore OE rad an flex fan no shroud and its built some with 3200 stall conv.It runs the same.Never overheats and his motor has never been apart.You might be suprised whats behind the 2 drain plugs in the block.Rocky

71 383, clutch fan, factory shroud, 26" rad,
KMJ ALUMINUM WATERPUMP HOUSING!!!!! ,
Napa water pump. Never gets above 180 even on 100 degree days in traffic. I agree with possible crud or air in your system.

The milodon pump is a stock HV pump with a plate attached to the back of the impeller to reduce cavitation. I don't think the flow is much different than a stock HV pump. I use a Summit cheapy alumimum HV pump on the 493 and it runs just fine.

Are you sure your gauge is accurate? 220 is not bad in a pressurized system, but it could be lower with a better matched cooling system. The 65's have a pretty narrow radiator; 22" I believe and if it isn't 4-core with a good flex fan (the 70's 5 or 7 blade stock versions are great) with a shroud it will run hot.

Some thoughts, I would try bypassing the rad on the trans fluid/taking the stat out for 1 day/going up 4-5 sizes in jets/checking for slight combustion leak into coolant. Good luck & holler when you find it.

...Just a reminder. If you pull the thermo, make sure you keep and eye on the over flow from the cap, because the removal of the stat exposes the spring in the cap to full system pressure now, fooling a lot of us into thinking it's overheating because of to much flow. When it could be over heating from less fluid in the system. Cross flows have the cap on the other side of the core, helping in that matter. Not trying to anything, we are all running on theory here because there are a lot of variables.

I just read the other thread on hot running and now I see this thread. I just HAVE to add.... because I was a doubter and now I swear I will no longer doubt.... the "high flow" Mr Gasket thermostats are NOT all good.


My Interceptor seeeemed to be running warm. I suspected it was despite a fancy high tech lazer thermometer (or whatever they are) which read 180 degrees when my gauge was at the red zone on the upper rad bung.
I ended up with a slight coolant leak on my thermostat housing (THANKFULLY!) and I went out and bought a gasket. I bought a 160 degree Stant thermostat also, JUST IN CASE!

I tossed my 160 degree MMr Gasket high flow thermostat beside the new Stant 160 degree thermostat into a pot of water. Turned on the heat and tossed in a temperature probe.
The Stant stat started to open at 165 degrees and was fully open by 170 degrees.
The Mr. Gasket thermostat NEVER OPENED. The water was at 210 degrees, the Mr. Gasket Stat didn't seem phased by the heat!

Needless to say I have read many times that the Mr Gasket high flow stats were the cause of some people's heat problems. Now I can add my name to that list!

if the higher amp alt is all that is stopping you, then don't worry about it.
really if you relay the fan or use the feets fan setup, you don't need to do the bypass.

yes the alt could put out more amps, but your system isn't drawing more amps. So more amps don't push into your system.