'68 GTX 440HP Over Heating

[JoePapa]

I inherited my Father's GTX. He had owned it since March of 1969. The car has always ran HOT! The car is a 440HP Automatic, 727 Torq Flight, 323 rear gear, with Power steering, no A/C. The car came with a 22" Radiator, which was possible for no A/C cars.
My dad had to replace the original radiator with an aftermarket in the mid-70's. It still ran hot! He had the motor rebuilt in 2002 and 2016 with a slight bore, and aftermarket pistons but nothing crazy.
It still runs hot and can overheat in stop & go traffic if not parked and shut off. He has a factory Clutch Fan System setup and factory fan shroud on the car.

I am interested in a US Radiator setup with High Efficiency 4 Row core.
Has anyone tried this Radiator setup and had success with keeping the engine cooled?

 

[1968rt]

Before you spend a lot of money, I would look into the water pump and pulley setup. Maybe an AC pump with a smaller WP pulley or a larger crank pulley? Im sure someone else here knows about pulley setups. AC vs Non AC Water Pump comparison

 

[oldbee]

Also, your fan clutch could be bad(slipping too much).

 

[MarPar]

Or your ignition is too advanced(?). I can't remember which is which.

 

[turbine68rt]

Or your ignition is too advanced(?). I can't remember which is which.

If it's too retarded it could contribute to running hot. The first thing I'd be checking is the timing.

 

[pnora]

Make sure your gauge is accurate.

 

[oldbee]

Like Marpar said,,,, still at 5*BTDC? Maybe try 8-10* at idle.

 

[turbine68rt]

Your setup originally came with a 22" radiator, a fixed blade fan with spacer, and a 2 piece metal shroud. I have the identical drivetrain and it hovers around 170-180 all day with timing at 18/18.

 

[JoePapa]

If it's too retarded it could contribute to running hot. The first thing I'd be checking is the timing.

No, not the issue. Thank you

 

[turbine68rt]

No, not the issue. Thank you

What are your timing specs?

 

[JoePapa]

Before you spend a lot of money, I would look into the water pump and pulley setup. Maybe an AC pump with a smaller WP pulley or a larger crank pulley? Im sure someone else here knows about pulley setups. AC vs Non AC Water Pump comparison

No, not the issue. Thank you

 

[super-bee_ski]

Perhaps take radiator out and have it tested and "Rodded"
That is the process of cleaning out the tubes, a technician remove both top and Bottom tanks, inserts a "rod" like item in each tube to unclog plaque buildup...from 45 years ago.
I have had this accomplished a couple of times.

 

[MarPar]

No, not the issue. Thank you

No, not the issue. Thank you

 

[ruffcut]

I recommend a Flowcooler water pump. Call me crazy, but it may solve the problem. ruffcut

 

[MarPar]

Could try water wetter also.

 

[Orig69]

The 440 engine in my car still has the original 22 inch radiator and the original clutch fan it usually runs at 180, in traffic 190

You did not mention what temperature the engine is at when it overheats?

 

[Michael_]

Make sure your gauge is accurate.

Yes buy a IR Thermometer and check directly on the engine.

But with all the stuff that has already been replaced and ruled out and the fact that the engine has been rebuilt 2 times and its still doing idk.
Maybe the water passages inside the block itself? But then the car is basically overheating since it's been new...

I'd might just replace the whole engine with all accessories.

 

[RemCharger]

Before you spend a lot of money, I would look into the water pump and pulley setup. Maybe an AC pump with a smaller WP pulley or a larger crank pulley? Im sure someone else here knows about pulley setups. AC vs Non AC Water Pump comparison

No, not the issue. Thank you

By, " not the issue" you've already tried exactly what was suggested?

 

[eldubb440]

I'd advance it till it pings, and back it off a little........

 

[RJRENTON]

Before you spend a lot of money, I would look into the water pump and pulley setup. Maybe an AC pump with a smaller WP pulley or a larger crank pulley? Im sure someone else here knows about pulley setups. AC vs Non AC Water Pump comparison

Quit fiddlely ******* around with over market aluminum radiators, timing adjustments, mixture adjustments, spark plugs, thermostats, vacuum leaks and bad grounds, shrouds, and fan clutches, and CALL BOB @ GLENN RADIATORS and buy the max cool correct rad for your car. The Glenn Ray RADIATORS are first class , fit and function better than original. NOT INEXPENSIVE (~ $ 1400 plus shipping)....but worth the price. Set the car up as OEM MOPAR.....and do yourself a favor and quit listening to the "also rans" that tried the variations UNSUCCESSFULLY.....do it correctly the first time. Use the HEMI water pump and sheave assembly #2946716 for max flow velocity and greatest efficiency along with the MOPAR #2806070 TORQUE DRIVE FAN CLUTCH ....not anything HAYDEN.....and go down the road without worry....
BOB RENTON