'68 GTX 440HP Over Heating

[Kern Dog]

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.

For several months I had Dwayne’s Plymouth here in my garage as I did a few things to the car. He has an aftermarket aluminum radiator in it that uses two 1 1/4” tubes. Add that to the fins and case and that was a thick radiator. The 2947 Hayden was the only unit that I knows of that would fit. We tried a fixed blade fan at first that pulled a LOT of air but sounded like a jet turbine it was so loud. Either would have worked, the fixed fan or the clutch mounted one. The car got a aftermarket HVAC system so cooling was going to be of real importance.

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

 

[RJRENTON]

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

I won't use the HAYDEN offerings.....to me they just look cheese ball.....i PREFER the OEM MOPAR....torque drive NOT thermal drive.....just my opinion of course...
BOB RENTON

 

[moparedtn]

For several months I had Dwayne’s Plymouth here in my garage as I did a few things to the car. He has an aftermarket aluminum radiator in it that uses two 1 1/4” tubes. Add that to the fins and case and that was a thick radiator. The 2947 Hayden was the only unit that I knows of that would fit. We tried a fixed blade fan at first that pulled a LOT of air but sounded like a jet turbine it was so loud. Either would have worked, the fixed fan or the clutch mounted one. The car got a aftermarket HVAC system so cooling was going to be of real importance.

The one in Fred: Griffin ExactFit Radiator for 68 Plymouth GTX - Part Number 5-00004
Mercy, they got real expensive since I got one...

Yeah, that Hayden... A little too close for comfort on Fred, so it was nixed:
Cooling issues - and a weird question

My entire thread on redoing Fred's entire cooling system - which did include some customizing (imagine that...):
Cooling issues - and a weird question

 

[moparedtn]

Oh, correction on my fan - it's a 6-blade, not 7. Bought on the advice of @coloradodave .
It's not noisy at all and with the use of the spacer in that thread, the half-in/half-out goal is achieved.
This is the fan: Allstar Performance ALL30100 Allstar Performance 6-Blade Fans | Summit Racing

 

[RJRENTON]

The problem the majority of the contributions is a lack or insufficient knowledge of thermodynamics and the willingness to accept the vendor's or your buddies expectations and explanations of how things work. Yes.., cost can be a consideration but the overall objective has got to be a a correctly functioning cooling system under 95% operating conditions under extreme ambient conditions. These contributions are perfectly willing to accept vendor's info without question, because they're the experts (the vendor's). Their underlying motivation is to sell you what they want you buy.....their profit margins * By the time all the suggestions (shrouds, fan blades, Hayden clutches, spacing) along with a myriad of other suggestions by well meaning others, you'll have the GLENN RAY RADIATORS BAUGHT AND DELIVERED AND TOTALLY FUNCTIONAL...but as the expression goes: "you pay your money and take choice......then complain when things don't work out......one must do their own du diligence; rather than an uneducated buddy opinion ....just my opinion of course..... terms like a "**** ton" of air means nothing."...use real terms like velocity in ft/sec; cubic ft of coolant, temperature of both the coolant b4 and after; air temperatures b4 and after the heat exchanger; specific heat of the coolant, for example. If your vendor can not supply sufficient data to satisfy your REQUIREMENTS.....FIND ANOTHER VENDOR.....
BOB RENTON

 

[RemCharger]

Agreed. Everyone should start investing in some real equipment and get some real air flow data. So we don't have to ask fellow enthusiasts what products worked for them .case closed, shut FBBO down . Thanks

 

[Kern Dog]

 

[jdsgtx]

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?

I had that problem! Get rid of the clutch fan

 

[Mr Mopar CO]

After reading this post, I had to chime in. I had a super nice, completely stock, 69 440+6 Super Bee that always ran hot. I tried everything. Finally I called Bob at Glenn Ray radiators. I ended up with the most beautiful, factory correct radiator that was so well done, I didn't need to do anything but bolt it in. Problem solved. Runs 190 all the time in traffic. I really wish I had done this years ago.

 

[1KoolBee]

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.

 

[1KoolBee]

Assuming you have a good clutch fan, Get your radiator recored with more tubes or just bite the bullet and get a Glen Ray radiator. My dad used to have a ‘68 polara, 383 2bbl and it had air and he towed a 20’ Prowler travel trailer with it, plus the dog, us kids and whatever else he could throw in there. The factory 22” 2-row overheated all the time. He tried all kinds of gimmicks, none worked. He finally put a 4 row 22” in it and it never got off “normal” (180 thermostat) no matter what he threw at it. If after radiator change, you need more low speed cooling, get a clutch fan off of a factory a/c car, they have 1/2” more blade pitch. Flex fans and electric fans are not necessary.

 

[Sixpactogo]

Everyone seems to think a bigger radiator or a Glen Ray radiator will solve any heat problems. I too, went down that road years ago. Had Bob build me a $700.00 radiator. Added a thermo fan and shroud and squandered more money with the water wetter BS and a BeCool water pump when my whole problem with over heating in heavy traffic was all caused by the March pulley serpentine set up I thought I had to have. Looked great but the underdrive system was not moving the coolant fast enough and was keeping it in the engine too long. Went back to the factory pulleys and no more overheating issues. Turns out the factory engineers had already dealt with that problem. That was my reasoning for asking the question in post 40. It happens a lot but it seems a good looking engine compartment matters much more than a good functioning one.
Might be what is going on here.

 

[Kern Dog]

I just found pictures of the ECP/SpeedCooling 26" radiator that I have in both Chargers.

I trial fitted a few different shrouds I had here. The one above was from a Chrysler Fifth Avenue for use with a 19 1/2" fan.

 

[Black_Sheep]

My combo consists of the following:

Milodon high volume water pump
Robert Shaw thermostat
Factory pulleys
Hayden thermal fan clutch
6 Pack / HEMI fan
NOS shroud
Factory 22” radiator
50/50 coolant mix
Stand alone transmission cooler

It took some effort to sort out the car when it was first built. It ran hot in the original configuration with a recored factory radiator using a direct drive fan and no shroud. I changed the water pump and t-stat first. It helped but still ran hot. Next I swapped to a Jaguar viscous clutch and 6 Pack/HEMI fan. Again, it helped but still ran hotter than I liked at low speed. At the time the only 22” shroud I could find was a fiberglass reproduction which fit like ****. A NOS shroud showed up on Tony’s parts website so I rolled the dice and bought it. I ran it that way for 20+ years, even on extremely hot days (100+ F) it didn’t come close to overheating. I had Glen Ray recore the radiator when I did an engine compartment refurb over the winter of 2022-2023 and replaced the failing Jaguar viscous fan clutch with a Hayden thermal unit. Coolant temperature stays rock steady around 180 degrees F.

 

[moparx]

I just found pictures of the ECP/SpeedCooling 26" radiator that I have in both Chargers.

View attachment 1716406

I trial fitted a few different shrouds I had here. The one above was from a Chrysler Fifth Avenue for use with a 19 1/2" fan.


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i bought one of those 2, 1 1/2" core size chinesium 26" radiators for my charger. it was around $100.00 if i remember right. using a 185 thermostat and a worn out 7 blade clutch fan, with no shroud, and a factory water pump/pulley size setup. recurved distributor with 16* initial - 37[ish] total mechanical advance, and am still fiddling with adjusting the vacuum can on the distributor. [3/32" allen key inserted in the hose nipple to tailor the diaphram spring], and with a very well sorted thermo-quad [the large one with the 1 1/2" primary butterfly's], the car runs 170/175 all day long. however, before i installed the chinesium radiaror, i had a factory 26" ac radiator from a chrysler wagon installed when i got the car out of hibernation [since 2006] last year about this time. it ran hot, and i discovered the radiator got plugged ! turns out, the block was full of $hit, and it migrated into the radiator, plugging it. i took out the block plugs, and removed the water pump and housing, flushing out the block after i scraped out what chunks of crud i could get to, until the water ran clear. it now works the way it is supposed to !
and of COURSE life "got in the way", so i haven't been able to have as much fun with it as i had hoped to this year.............

oh, and by the way K-dog, PLEASE get rid of that "clamp-on" positive battery cable end ! [the one item of many that REALLY trips my trigger !]
a quality crimp/solder replacement end or a new cable is my recommendation ! [just bustin' yer balls, but those things reall get to me !]

 

[HEMI-ITIS]

I am far from stock,545ci blown 9 sec hemi, street driven and raced once in a while.
Running a $200 afco 26 inch aluminum rad and a $135 Spall electric pusher fan with no shroud.
It will creep up to 190* in bumper to bumper traffic.It has a small 6 cylinder w/p pulley,stock aluminum w/p housing with a MOPAR aluminum water pump.Normally runs at 175/180*.
I read about guys spending over a grand for a radiator and and just shake my head!

 

[moparx]

I am far from stock,545ci blown 9 sec hemi, street driven and raced once in a while.
Running a $200 afco 26 inch aluminum rad and a $135 Spall electric pusher fan with no shroud.
It will creep up to 190* in bumper to bumper traffic.It has a small 6 cylinder w/p pulley,stock aluminum w/p housing with a MOPAR aluminum water pump.Normally runs at 175/180*.
I read about guys spending over a grand for a radiator and and just shake my head!

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View attachment 1716712

Glad to see you are still kickin' 'Itis !

 

[Geoff 2]

As usual Bob Renton, you play the Bullshit Baffles brains syndrome using lots of techno speak & then criticising others for not offering proof.
Where is the proof that Glenn radiators, the max velocity/greatest efficiency [ post #20 ]. What other rads were these rads compared to & where are the numbers??
Where are the fluid velocity #s, volume #s, & air flow velocity #s [ post #28 ] that you ask of others....but fail to provide in YOUR posts?????????????????????????

 

[Vinny]

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?

MAKE SURE THE FAN CLUTCH IS NOT SLIPPING. My A12 temp would rise in minutes. I tried all the usual repairs. Then I figured I would change the fan clutch. Bingo, problem solved. That made me a happy man. Now I drive with confidence. I used a reproduction 070 clutch.

 

[Vinny]

Bob... who manufactures the Mopar fan clutches ?

Tony's