Cooling Issue - 1964 Dart GT - 273 with automatic and A/C

trapster said:

1964 v8 radiator shroud, is both slightly ineffective and extremely rare.

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cudamark said:

A properly designed and build shroud can be very effective. If the OP isn't worried about originality, I'd make one that directs almost all the air through the radiator. Some sheet metal and rubber sheets cut to fit and riveted/bolted in the right places could do wonders.

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slantsixdan said:

Given the choice, I'll take limited efficacy over no efficacy (no shroud).

As for rare: yep, pre-'67 A-body fan shrouds are all rare, and the earlier the build year the rarer they get. That said, I'm guessing fairly good odds there might be one at one or another of the Arizona old-car yards, or maybe hanging on the wall at Wildcat. If someone were to happen upon one, it would not be difficult to reproduce.

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JDMopar said:

A small part of the OP's troubles may come from where he lives. The Columbia, SC area gets stifling hot! When somebody in hell pisses the devil off, he sends them to Columbia for punishment! @Dart5150 research water pump pulley's for 64-69 cars with AC. I think the pulley's on them are smaller, to overdrive the pump like Rob said. Bouchillon Performance, down around Charleston sells reproduction pulleys, so maybe they will have what you need. You will need one for a 64-69 car because you have a cast iron water pump. The depth of the pulleys changed in 70 when they went to the longer nosed aluminum water pump. Your Dart sure looks nice, so I hope you can get it sorted out.

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cudamark said:

'64 A-bodies all came with 19" wide radiators from the factory. The factory A/C car got a 3 row cored radiator, but, I don't believe they had a shroud that year on the V8. If they did, I've never seen one. I would use a rigid 6 or 7 blade fan blade....no flex fan. If your engine runs cool enough at speed, the flow is probably ok, and it's mostly an air flow issue at idle/stop. A mismatch on pump/pulley combo can have an effect too that can be masked at higher than idle RPM. As a rule, the non-A/C cars used an 8 impeller pump and a larger diameter water pump pulley. The A/C cars used a 6 impeller pump with a smaller diameter pulley. Seems backwards eh? It has to do with water flow. The non-A/C pump has more impellers, but, spins slower than it's A/C sister, which spins faster at a given RPM. A mismatch can have strange results sometimes....but not always. I've seen 8 impeller pumps have no problem on A/C cars, and others that had cavitation issues with the coolant foaming up to the point where it wouldn't cool properly. The opposite can be true using a 6 impeller pump on a non-A/C car where the flow is inadequate. It also has an effect on the fan speed if you have the wrong pulley combination. The '64 A-bodies with a V8 had one strike against them with that small radiator, which was improved to the 22" radiator the next year. Converting isn't all that easy, but, I've seen it done. If I were you, I'd probably go with a heavier duty radiator, 7 blade rigid fan, and fabricate a fan shroud for better air flow at low RPM. This is all assuming that the engine cylinders weren't bored too thin and is running with the proper air/fuel ratio.

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slantsixdan said:

Your luck with repairs and upgrades will get a lot better once you start disregarding the existence of that garbage company selling garbage parts at LOLWTF prices.

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Dart5150 said:

slantsixdan I'm new to Mopar (my experience is with Datsun Roadsters and Karmann Ghias), so I'm open to recommendations for good vendors, especially one selling accurate reproduction radiators. I'd like nothing more than to get rid of that ugly aluminum rad and have a more stock looking rad. It mocks me every time I open the hood, lol. Can you recommend a radiator vendor?

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slantsixdan said:

That is not the case. For one thing, there was nothing such as a factory A/C A-body in '64; that started in '65. The '64 A-body A/C was still a dealer-installed package, which did not include a new radiator. And even in '65, the factory A/C cars didn't get 3-row radiators.



Fan shrouds were available for the '64 A-bodies with \6 and with V8 engines. They were typically installed on cars with A/C installed and/or trailer-tow equipment. '64 was the last year for the ring-style shroud; starting in '65 they were box-type shrouds. Both kinds were 2-piece items, upper/lower.

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Read this.



Yup, low-speed/stopped-in-traffic heatup is usually a matter of insufficient effective airflow across the rad. Make sure there's an adequate fan, a shroud will help quite a lot, and install the hood-to-rad-support seal on the underside of the hood; that's another A/C and trailer-tow piece to prevent air going up over the radiator instead of through it. Gary Goers № W81, available (if anywhere) from Quirey Quality Design, the outfit who bought out Goers when his health failed.



As built yep, they did. That strike could easily be erased even back in the day by having a 3-row core put into the stock rad (easy on the V8 cars; plenty of room between front of engine and back of rad). Decades later, high-efficiency rad cores with denser fins made it even less necessary to try to hack in a wider rad, and now we can do it even better still.

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Dart5150 said:

As an FYI, Quirey no longer offers the W81 hood/rad seal. He referred me to Dante's, who don't offer one either.

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JDMopar said:

@Dart5150 Check around your area and see if you can find an old school radiator shop that the EPA hasn't shut down yet, and see if they can do a re-core on an original radiator. I just drove thru Columbia this morning on the way to the beach....and the outside thermometer on my truck went up 4 degrees like it always does. Although, it only went to 72 at that time. I bet people outside were in parkas! lol. If you can find a shop that will do that work, shoot me a PM. I have a 22" radiator with a factory plastic shroud that I will probably never use and we can work something out. I know nothing about it, other than I took it out of a parts car. Probably a 69 Dart I parted out years ago. I'm sure it would need to be re-cored. I'll check it when I get home Wednesday and see how many rows it has.

Before Mike & or Mike smack me for twisting this to a 4 sail post.....it will be free and so will delivery since I go thru his area a few times a month.

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valiantpatrol said:

When I moved to the Tucson area my car had a 160 deg thermostat which in traffic allowed heat to build to point of spitting out my overflow. I also had an aluminum radiator. I switched to 190 deg thermostat to increase dwell time in radiator. Worked well to solve my problem. For me it seemed counterintuitive to solve the problem, but it did work in my case. Glad I listened to radiator guy.

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slantsixdan said:

That is not the case. For one thing, there was nothing such as a factory A/C A-body in '64; that started in '65. The '64 A-body A/C was still a dealer-installed package, which did not include a new radiator. And even in '65, the factory A/C cars didn't get 3-row radiators.



Fan shrouds were available for the '64 A-bodies with \6 and with V8 engines. They were typically installed on cars with A/C installed and/or trailer-tow equipment. '64 was the last year for the ring-style shroud; starting in '65 they were box-type shrouds. Both kinds were 2-piece items, upper/lower.

View attachment 1716292338



Read this.



Yup, low-speed/stopped-in-traffic heatup is usually a matter of insufficient effective airflow across the rad. Make sure there's an adequate fan, a shroud will help quite a lot, and install the hood-to-rad-support seal on the underside of the hood; that's another A/C and trailer-tow piece to prevent air going up over the radiator instead of through it. Gary Goers № W81, available (if anywhere) from Quirey Quality Design, the outfit who bought out Goers when his health failed.



As built yep, they did. That strike could easily be erased even back in the day by having a 3-row core put into the stock rad (easy on the V8 cars; plenty of room between front of engine and back of rad). Decades later, high-efficiency rad cores with denser fins made it even less necessary to try to hack in a wider rad, and now we can do it even better still.

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ggodec said:

I’ll add a bite for water wetter, seems silly but it definitely seems to help, I’ve been using 1-1.5 bottles in my dart and barracuda. I have started using the Flowkool water pumps, more blades and seems to flow better. Timing/AFR have been the culprit when I couldn’t get heat under control but once they were dialed in even on 100 degree days in CO all three of my Mopars have stoped creeping above midline and to the better turn the heater on high/hot to save going to far. /6 (Torqstorm), 340 and 408 all had issues but one step at a time all solved now.

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Dart5150 said:

Hello all. Apologies for the length of the post, but I wanted to be thorough. I'm having a cooling issue that I can't seem to chase down, was hoping for some insight from those farther along the Mopar journey than I am. Pictures are below.

We have a '64 Dart with a 273 and push-button automatic. Also has AC and power steering. I'm not sure if the AC is factory/original, but the compressor is Mopar and there is a Mopar branded evaporator/blower mounted under the dash. The AC is currently disabled, as I had to repair some leaks and I need to charge it (but wanted to address the cooling issues first). The radiator is an aftermarket aluminum radiator, and has two 1-inch rows, which I've heard is enough for a small block V-8. It has a 7-blade fan that is about 17" in diameter, with about a 1-inch overhang on the passenger side of the radiator. No shroud, which I've heard is normal for early A-Bodies. The radiator core is roughly 16" high by 18" wide, and the mounting point on the radiator support panel are about 21.25" on center.

Anyway, the car runs at ideal temp when cruising, right up the middle of the gauge, but approaches the hot side of the temp gauge on a 90+ degree day and/or in stop and go traffic. Quickly enough that I either find a way to get moving again or pull over for a cool down. So starting with the simple stuff first, I pulled the thermostat and found that it had failed open, which I had suspected. I replaced it, but this didn't resolve the issue. Next, thinking the radiator may be too small (and wanting something more stock in appearance anyway), I ordered the radiator from Classic Industries that's supposed to fit the '64 Dart with a V-8. It was too big, and didn't align with any of the factory mounting holes. Next I installed an electric fan with a relay, and this didn't help. Part of the problem with the electric fan is that I only had 3.2" of clearance between the radiator surface and the fan pulley. So that limited my airflow options, although the one I bought was a slim fan rated for over 1900 cfm. Then I pulled the fan and reinstalled the mechanical fan because the electric fan didn't help and it sounds like a 747 on final approach .

So I have some questions.

1 - Is it possible that somebody swapped a V-8 into a Slant-6 car, and there is a different radiator support panel for the V-8 car? I ask because a larger radiator will have to draw air through the same sized opening in that panel anyway.

2 - Is there a different water pump/pulley for a V-8 car with AC?

3 - Are there any known cooling issues with these engines? For example, I know that it's easy to incorrectly orient or 'flip' the head gaskets on a Ford 289 if you don't pay close attention, which results in overheating issues.

Thanks in advance for any insight you may be able to provide.

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Swinger 340 said:

No one mentioned if the car has a fan clutch. The clutch could be slipping at idle, causing the overheating. All AC cars I know of have thermo clutches. They have the spring at the center, facing the radiator.

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toolmanmike said:

I just cruised through 41 posts here and I think I missed where your are having overheating issues. How hot does it get? Factory gauge (just a guess there) Is it puking coolant out?

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Dart5150 said:

Factory gauge. Not puking coolant, but the temp gauge quickly creeps up to the line just before 'H', at which point I find a way to get moving or shut it down.

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Swinger 340 said:

When any of my vehicles overheat, the first thing I check is the lower radiator hose collapsing. If so, time for a new hose. I don't think inner springs are used any longer. Just a stiffer rubber and over time it softens.

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ggodec said:

I’ll add a bite for water wetter, seems silly but it definitely seems to help, I’ve been using 1-1.5 bottles in my dart and barracuda. I have started using the Flowkool water pumps, more blades and seems to flow better. Timing/AFR have been the culprit when I couldn’t get heat under control but once they were dialed in even on 100 degree days in CO all three of my Mopars have stoped creeping above midline and to the better turn the heater on high/hot to save going to far. /6 (Torqstorm), 340 and 408 all had issues but one step at a time all solved now.

Click to expand...