Revert to Factory Engine Cooling

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charliec

charliec

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When I bought my car ('68 Dart GTS, 340, 4 Spd) it had the factory stock (18x22) radiator with a FlexFan and no shroud. It was kind of an aberation of parts that seemed to work OK. However, I didn't drive it much before I started dismantiling it for restoration, so I can't say whether it was really working well. I now want to go to a more-or-less factory setup with the possible exception of an aftermarket radiator. The old radiator looks to be in fairly rugged condition, and I figure I will come out dollars ahead by going the aftermarket route rather than finding a radiator shop that wants premium pricing to work on the old one. The car is equipped with factory AC, but it's questionable whether I'll ever make it functional. For now, I'll just consider it an un-air conditioned car and set up the engine cooling system accordingly.

In any case, since I don't have any of the original parts, its hard to tell exactly what I'm missing. I know the obvious things I'll need such as a fan and a shroud. But I don't know about any spacers, clutch fan drive, etc. The FSM is fairly slim on information, but the best I can figure I will come off of the water pump with a pulley, a 2" spacer and an 18"- 7 blade fan.

Is there a thermal clutch involved also, and if so does that change the use of the 2" spacer?

Any advice as to how the stock set-up should look would be appreciated.


Set-up as received and as currently configured.

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You can trace back the parts using the 1969 online parts book at mymopar. It will give you the correct parts numbers.
 
Most aftermarket radiators don’t fit well with factory fan shrouds. So two steps forward, one step back.

You will have reliable cooling with this if the car is in tune:

-factory shroud. It’s molded to fit snug against a factory radiator
-Fan clutch like factory had. Hayden sells a short muscle car thermostatic clutch
-7 blade fan
-recore you factory radiator with high density core. They have higher fins per inch and more tubes. Is you original radiator the correct numbers?

If/When you rebuild your motor, stick cloths hanger into the freeze plug holes to remove sediment and loose rust
 
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If you look at common ( Stant ) aftermarket thermostats vs a factory 'stat like that pic, the difference in diameter of the opening part of the thermostat is around 3/8". That is a tremendous difference in flow. My "theory" is that the aftermarket saddled us Mopar folks with Chebby stats back in the 70s or 80 at the dawn of all this when mo one knew better. I believe a good chunk of overheating problems of medium/high performance motors could be solved with a simple thermostat change. Just my idiot opinion.
 
Demonic said:
If you look at common ( Stant ) aftermarket thermostats vs a factory 'stat like that pic, the difference in diameter of the opening part of the thermostat is around 3/8". That is a tremendous difference in flow. My "theory" is that the aftermarket saddled us Mopar folks with Chebby stats back in the 70s or 80 at the dawn of all this when mo one knew better. I believe a good chunk of overheating problems of medium/high performance motors could be solved with a simple thermostat change. Just my idiot opinion.
Click to expand...
The Stewart Components stats are high flow & perfect for what the engines need. I've seen other "high flow" stats that were anything but.
 
I have been through the overheating ordeal and here is my advice for what it is worth:

Factory 7 blade fan with a heavy duty fan clutch
Make sure the fan is facing the right direction
Factory fan shroud
Stock AC water pump or a flowkooler
5.2 inch (about) water pump pulley (with ~7.2 crank pulley, fan speed is about 120% of crank speed)
Factory radiator, 3 core
High flow thermostat as mentioned above

If you buy an aftermarket radiator, make sure you get one this fits the factory shroud because there are not a lot of other good options. One really important lesson that I learned the hard way is THE FAN MUST BE 1/2 IN AND 1/2 OUT OF THE SHROUD. People told me this and I didn’t listen.

Since you have the cast (pre 1970) water pump, that gives you about 3/4 of an inch more clearance to the radiator, that makes things easier with an aftermarket radiator if you go that way.

Many aftermarket radiators are wider and positioned closer to the engine. This may be the cheapest solution, but it can create clearance issues in some cases.

Get a good hood to radiator support seal so all the air goes through the radiator, not around it.

Make sure your bottom hose has a spring in it to keep it from collapsing.

Whatever you do, DO NOT change to the 70 & up water pump & belt system. That is the biggest hole I fell into, & I pretty much fell in all of them. Everything changes when you do this.

If you have the AC brackets and pulleys, hold on to them. They are almost impossible to find.
 
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Mike69cuda said:
I have been through the overheating ordeal and here is my advice for what it is worth:

Factory 7 blade fan with a heavy duty fan clutch
Make sure the fan is facing the right direction
Factory fan shroud
Stock AC water pump or a flowkooler
5.2 inch (about) water pump pulley (with ~7.2 crank pulley, fan speed is about 120% or crank speed)
Factory radiator, 3 core
High flow thermostat as mentioned above

If you buy an aftermarket radiator, make sure you get one this fits the factory shroud because there are not a lot of other good options. One really important lesson that I learned the hard way is THE FAN MUST BE 1/2 IN AND 1/2 OUT OF THE SHROUD. People told me this and I didn’t listen.

Since you have the cast (pre 1970) water pump, that gives you about 3/4 of an inch more clearance to the radiator, that makes things easier with an aftermarket radiator if you go that way.

Many aftermarket radiators are wider and positioned closer to the engine. This may be the cheapest solution, but it can create clearance issues in some cases.

Get a good hood to radiator support seal so all the air goes through the radiator, not around it.

Make sure your bottom hose has a spring in it to keep it from collapsing.

Whatever you do, DO NOT change to the 70 & up water pump & belt system. That is the biggest hole I fell into, & I pretty much fell in all of them. Everything changes when you do this.

If you have the AC brackets and pulleys, hold on to them. They are almost impossible to find.
Click to expand...
+1 for the Flowkooler water pump. I've put them on both my small & big block engines.
 
You're in the same boat I was 30 years ago with my '67 B'cuda.
The engine has a '70 up water pump and timing cover.
If you insist on staying with that, then have a custom radiator made using a 70 bottom and a '68-69 top and core.
The first one I had done was based on a '70 (squre top) and resoldered the mounting brackets so the top tank was slightly over the body radiator support.
That one was used with a Chrysler flex fan ('till a blade seperated) and then MP 5 blade fan and clutch but no shroud. No shroud meant slight temperature creep when stopped or crawling in hot weather.
When the core was pretty much done for a few years ago I paid Bob at Glenray Radiator to make one up based on a '68-69. Advantage is that all of the 68-69 parts work. The clutch fan is clearanced for the bubble top tank, I could use a new replacement clutch that wasn't ridiculously short, repro shrouds are available and bolt right up. Yes it cost more, and I had to send it back once to make it shorter. But Bob was good to do business with and the workmanship is great.

Another lesson. Use only Conventional Coolant with distilled water. Not universal which is always some version of HOAT and doesn't protect solder and copper from corossion nearly as effectively as the the older IAT type coolant.

Some photos here:
www.forabodiesonly.com

from the top of the front core support to the top of the radiator cap

For a second generation Barracuda, (1968) what is the distance from the top of the core support to the top of the radiator cap? I installed a Champion Radiator, and it looks like it is setting too low, the radiator cap is about flush with the top of the core support. I want to raise the...
www.forabodiesonly.com www.forabodiesonly.com

Some more info here on clearances
www.forabodiesonly.com

What is the correct fan to radiator clearance?

70 340 installed in 68 Barracuda. Installed 68 water pump and low profile Hayden fan clutch. Distance between fan and radiator is 2 3/8 inches. Radiator side of fan is at shroud opening meaning not below outside edge of shroud. Have opportunity at this point before I continue is to install...
www.forabodiesonly.com www.forabodiesonly.com
 
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Oh yeah, forgot to mention the Hayden 2947 fan clutch I had to use with the aftermarket radiator. It is the shortest one made, I think. Be prepared to use every swear word you know if you buy one. The clearances are so tight, it is almost impossible to install. I had to use it since I had the 70 up water pump which is about 3/4 inch longer.
 
lots of great suggestions above and i'll share the sentiment of keeping it factory. the factory "bubble top" radiator and shroud with a clutch fan is a tough combo to beat.

i understand if you don't wanna splash the cash for a new waterpump, but the flow cooler unit is a very nice piece and well worth the loot.

get a *good* t-stat, not some parts store junk or something labeled "race" or some such nonsense.

i've run that set up for the past 25+ years and it'll pound the pavement at 100mph thru texas in august and not break a sweat; and sit idling in LA traffic on a 110* day just cool as a cucumber.

ETA: you're going to need to lose that adapter you have on the bypass coming out of the pump. it's way too tall and you won't make the turn going into the manifold without kinking it.
 
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This is the old radiator that came on the car. I can't find a part number on it, although it is definately a mopar part. Parts manual calls for 2898026. The old on is pretty knocked up; dents in the bottom tank, bent fins, corrosion, multiple old repairs, and not sure the bottom hose connection isn't bent upwards due to dent in lower tank.
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that looks pretty rough and tumble. i'd get a quote on repairing it, but be prepared to buy a new one.

there's really good units from OER, Glen Ray, US radiator. expect to drop coin though. there's also aftermarket aluminum units, but if you're a stickler for the classic "look" then you're gonna be turned off by them. however, if you go for an aftermarket aluminum don't buy a cheap *** one with plastic tanks. same adage applies: you get what you pay for.
 
Bob at Glen Ray can answer all of your questions about your radiator. If you should choose him to rebuild your radiator, you will be absolutely impressed with his work.
 
I would suggest a Cold Case Radiator. These are aluminum radiators with 2 rows of large tubes. Avoid cheap aluminum radiators with flat tubes like you see in brass/copper original radiator. The Cold Case radiators are made to use the stock shroud, although there was a gap on my 1970 set up it cools exceptionally well.
 
That radiator have room for a clutch fan?
I had to use a cast iron pump with my Cold Case. Otherwise it was fine.
 
Use Hayden #2947 short shaft clutch. Made specifically for these applications after a campaign by members here. Can't remember who head this up, but I thank them every time I work on the front of my engine!
 
That is the clutch that I used, not all radiators are alike. That's why I try to pay close attention to the wording. Especially after a member screwed me on a supposedly new OER radiater, that have no idea what it was for.
 
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