'68 GTX 440HP Over Heating

[WileE]

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

Bob... who manufactures the Mopar fan clutches ?

 

[Geoff 2]

Hayden?

 

[Geoff 2]

Joe,
Overheating heating engines can be realllllllly hard to fix. Especially if they have run hot from day one....
There could be an internal problem....excessive friction... creating the heat. Or thin bore walls.
If the ign timing is correct & the carb is not lean, what do you do because nothing obvious jumps out?

I would improve the cooling system:
- better water pump, one that has both sides of the impeller closed. I have been doing this mod for 20+ years.......because it works. I weld or braze a 'donut' onto the open side of the impeller. Some high end [ expensive ] pumps already have closed impellers. Why it works: without the impeller fully closed off, the impeller fails to capture all the water; just churns it up. With the impeller closed both sides, ALL the water is captured, to be sent through the engine.
- get the small water pump pulley; WP should be overdriven 10-20%.
- get an alum rad. Alum rads have been PROVEN to shed heat better than copper/brass. Although copper is a better heat conductor, the size of the tubes is limited. Not so with alum. Get a two two alum rad with 1.25" tubes. It is the bigger tubes that allows vastly more fin area, the finning being the medium that sheds the heat to the atmosphere. The fins are louvered which further enhances the heat shredding capability.

More tips here: www.stewartcomponents.com

 

[Kern Dog]

Are you willing to pay for that Glen Ray radiator? Sure, they are great for factory correct restorations but they are at least 4 times the cost of others that will work just fine. Maybe some guys that pay others to work on their cars can also afford to pay more than they have to but to me, it is stupid to pay more than you have to pay.
No, the nuclear option is not necessary. You don't need to spend that kind of money. I have the 2 row aluminum Speed Cooling radiators in both of my Chargers and those cars do not overheat.

I'm talking a $350 radiator and YES, a Hayden fan clutch, a 7 blade fan and shroud. BOOM. It works.
Just about everything that one member wrote is wrong or far more expensive than necessary. Where are you going to find a "Mopar" fan clutch anymore? Isn't Mopar Performance out of business now? The 3G Hemi has been out for over 20 years and it used a different type of clutch. That is what Ma Mopar has focused on.
I seriously doubt that Ma Mopar still makes a fan clutch to fit our cars. If anything, it would be outsourced like 99% of the stuff that they sold through Mopar Performance.
Here is a winning combination: 26" ECP/Speed Cooling radiator, factory shroud, Hayden 2947 fan clutch, 7 blade stock fan and a Flowkooler pump.

I've driven in 110 degree Sacramento heat with the A/C going and the temperature doesn't go over 200. No boil over either. I've had this setup for 5 years with thousands of miles with no trouble. I always run an even mix of anti-freeze and water. Check out the scale here:

There is some value to examining the tune of the car along with the efficiency of the exhaust system. A car that runs lean may run hotter. A car with restrictive exhaust will too. It wouldn't hurt to get a thermal gun and point it at several points in the system to see if the temperatures vary a lot. The top of the radiator, the bottom, the core, the thermostat housing, the water pump itself...
Good luck and be sure to report back if the advice you get works out for you.

 

[moparedtn]

Joe,
Overheating heating engines can be realllllllly hard to fix. Especially if they have run hot from day one....
There could be an internal problem....excessive friction... creating the heat. Or thin bore walls.
If the ign timing is correct & the carb is not lean, what do you do because nothing obvious jumps out?

I would improve the cooling system:
- better water pump, one that has both sides of the impeller closed. I have been doing this mod for 20+ years.......because it works. I weld or braze a 'donut' onto the open side of the impeller. Some high end [ expensive ] pumps already have closed impellers. Why it works: without the impeller fully closed off, the impeller fails to capture all the water; just churns it up. With the impeller closed both sides, ALL the water is captured, to be sent through the engine.
- get the small water pump pulley; WP should be overdriven 10-20%.
- get an alum rad. Alum rads have been PROVEN to shed heat better than copper/brass. Although copper is a better heat conductor, the size of the tubes is limited. Not so with alum. Get a two two alum rad with 1.25" tubes. It is the bigger tubes that allows vastly more fin area, the finning being the medium that sheds the heat to the atmosphere. The fins are louvered which further enhances the heat shredding capability.

More tips here: www.stewartcomponents.com

Some visual aids/part numbers would be really helpful here, especially on the "high end pumps" part.
I think I know what you're talking about, but seeing one would confirm that.
The pulley thing would benefit from a part number, too.

As far as radiators go, yes the GlenRay is huge money - I went with the Griffin "exact fit" aluminum one for
Fred, which has a very thick core with big-arse tubes as you describe. Extremely well built radiators, those
Griffins - the kind you'll keep around forever with any routine maintenance in them.
They also accept factory shrouds - and I did the whole 22" to 26" swap, complete with hacking out the
opening in the radiator support to suit.

 

[lewtot184]

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

My 69 r/t with the identical engine radiator combo does the same thing. The problem is 100% radiator. No timing, water pump, wetters, fans or any other gadget will fix the problem. Been there, done that! Get a better radiator. U.S. radiator is hit or miss. I don't know if Glenn Ray's does 22"....?

 

[hunt2elk]

I have Glen Ray built 22" radiators in front of both my big block strokers. 570ish hp. They don't run hot.

 

[RJRENTON]

Bob... who manufactures the Mopar fan clutches ?

Tony's parts sell repro Mopar torque drive fan clutchs. Plus there are on line Source's as well.
BOB RENTON

My 69 r/t with the identical engine radiator combo does the same thing. The problem is 100% radiator. No timing, water pump, wetters, fans or any other gadget will fix the problem. Been there, done that! Get a better radiator. U.S. radiator is hit or miss. I don't know if Glenn Ray's does 22"....?

Yes....Glenn Ray will build what you want/need
BOB RENTON

Joe,
Overheating heating engines can be realllllllly hard to fix. Especially if they have run hot from day one....
There could be an internal problem....excessive friction... creating the heat. Or thin bore walls.
If the ign timing is correct & the carb is not lean, what do you do because nothing obvious jumps out?

I would improve the cooling system:
- better water pump, one that has both sides of the impeller closed. I have been doing this mod for 20+ years.......because it works. I weld or braze a 'donut' onto the open side of the impeller. Some high end [ expensive ] pumps already have closed impellers. Why it works: without the impeller fully closed off, the impeller fails to capture all the water; just churns it up. With the impeller closed both sides, ALL the water is captured, to be sent through the engine.
- get the small water pump pulley; WP should be overdriven 10-20%.
- get an alum rad. Alum rads have been PROVEN to shed heat better than copper/brass. Although copper is a better heat conductor, the size of the tubes is limited. Not so with alum. Get a two two alum rad with 1.25" tubes. It is the bigger tubes that allows vastly more fin area, the finning being the medium that sheds the heat to the atmosphere. The fins are louvered which further enhances the heat shredding capability.

More tips here: www.stewartcomponents.com

Show your velocity and volume calculations as i have done previously.....again show us your heat transfer calculations not basted of manufacturer's boiler plate advertising numbers but actual thermodynamics...not the actual materials of construction surface srea of tubes AND THE WW fins between the tubes, the fluid velocities and volume (fluid side), and the air flow velocity and volume (air side) including temperatures. Typical one sided lack of total information .....
BOB RENTON

 

[WileE]

Tony's parts sell repro Mopar torque drive fan clutchs. Plus there are on line Source's as well.

Bob... not the question who sells the part, who manufactures the Mopar fan clutch you mention.

 

[lewtot184]

I have one of the Tony's parts fan clutches on one of my cars. They're a little loose. I'd prefer a higher viscosity fluid in the clutch. I probably wouldn't use one with a cooling problem. Fix the radiator first.

I've been looking into going after my cooling problem,....again. i bought a u.s. radiator a few years ago and the workmanship was awful. the top tank split after a couple of weeks and while getting that repaired noticed 37 tubes fully or partially soldered shut. the radiator wasn't flat and had a twist in it. basically defeated what i was trying to do but the basic idea showed promise if the workmanship had been good. so now i'm looking at the same idea (part number 352191) again. i'm thinking u.s. radiator may have moved to alabama from california. maybe they have better assemblers now? they do have some sort of coupon offer for purchasing but i have no idea how to access it. cost is a bit pricey; especially considering what i paid in 2015. i'd consider trying this again if i was sure the workmanship was good and could find the coupon offer. i do want to keep some semblance of stock appearing and i did keep the hoses and shroud from the first try at this.

 

[68BabyBlue]

I have one of the Tony's parts fan clutches on one of my cars. They're a little loose. I'd prefer a higher viscosity fluid in the clutch. I probably wouldn't use one with a cooling problem. Fix the radiator first.

I had the original factory 26" in my A/C GTX re-cored last year after problem with overheating, and replaced the fan clutch with the thermal drive reproduction from Tony's at the same time. Zero problems now. All other components are factory stock. Previous factory A/C GTX I owned in the 90s was special ordered with a fixed blade fan. Thinking the original owner might have heard of problems with thermal drives back in the day.

 

[lewtot184]

Another consideration is the bottom tank. A 4 row has to have the wider bottom tank; I'm thinking 2 1/2"+ in width. A standard 22" bottom tank will only take 3 rows. The 7 blade fixed fan with factory spacer won't safely fit a 4 row radiator. Some mods could be made to the brackets location to help.

 

[JoePapa]

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

Are you referring to Glenn-ray radiators? I have been to their website and it appears they only offer 26" Radiator. I need a 22" Radiator. I have not called yet to check.

 

[Kern Dog]

With a narrow radiator like the 22", the only way to increase capacity is to go thicker. That closes up the clearance to the fan, sometimes to the point where a clutch fan setup won't fit. If the car has always ran hot with a 22" unit, wouldn't you think a bigger radiator is a good idea?
Yes, you'd need to open up the core support to make it work.

 

[RJRENTON]

Bob... not the question who sells the part, who manufactures the Mopar fan clutch you mention.

To me, it doesn't matter who manufacturers the part, who sells the part but how it performs to my expectations. The torque drive fan clutch performs extremely well....pricey but worth the cost......
BOB RENTON

 

[moparedtn]

For the record, the Griffin "exact fit" I got is nearly 3" thick. As such, it negated the possibility of using a clutch
fan - not enough room for one, not even that popular "stubby" one from Hayden.
A direct drive setup was employed instead, using a 19" 7-blade fan with factory shroud.

 

[turbine68rt]

After running a clutch fan for over 30 years and replacing it a few times, for the last few years I switched to using the exact same hardware that came on the car since day one for several reasons.
A) It's an oem restoration.
B) The oem direct drive fan has not failed or worn out due to use.
C) It consistently maintains a 180° temperature.
D) It will only see street/show use. (Raced it in the 80's/90's but those days are over.)

Just like the points ignition that has been on the car since '68, that system has never left me stranded in nearly 40 years since I've owned it.

 

[WileE]

To me, it doesn't matter who manufacturers the part, who sells the part but how it performs to my expectations. The torque drive fan clutch performs extremely well....pricey but worth the cost......
BOB RENTON

So, doesn't Hayden manufacture that fan clutch ? I thought so.

 

[lewtot184]

I think the Hayden clutch is different. The Tony's mimics the '070 clutch.

 

[Sixpactogo]

You didn't mention it but are your running a serpentine pulley setup?