Would my Duster run cooler with an electric puller fan?

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Alan H.

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Just got my 1970 Duster 340 the other day.
Had to drive it on the highway about 20 miles each way today, and it ran very hot (one line below H on gauge). Outside temp was around 90, and on a wide-open highway cruising at 65-70.
I never had an electric fan, but do know a lot of cars use them down here. It is at least 90 every day from late May through early Sept. My '70 Roadrunner I just sold never got hot, even on the hottest day, but it had the 26" fan and shroud. The Duster has no shroud. My radiator is 22" wide and I would appreciate comments about the benefits of changing fans. Also, which brand is good, I don't need the "best".
Also, what is the price range I can expect to pay, and what size fan is recommended?
Here is my setup:
Duster_fan_collage_zpsushcp1cq.jpg

The car is recently totally restored, new water pump, radiator done, etc.
It did come out of Canada, so I will check which spark plugs are in it as suggested below. If I decide to change plugs, what plugs are recommended (brand,size and gap).
This is a stock rebuilt 340.
 
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Probably not. A fan is of little or no value to the cooling system when going down the road. Unless the fan can draw air through the radiator faster than a 70 mph head wind. The usual culprit is a forty year old radiator that doesn't flow like a new one. Followed by thermostat, timing, a/f ratio.....
 
Exactly, just what I was going to state.
I'd like to ad that a good clear clean flowing radiator with a fan shroud will work excellent. I would couple it to a viscous clutch and fan. Coolent at 50/50 min. mix. Hopefully the water pumps impeller isn't rotted away as well.

While your under the hood, a quick check of the cars fuel ratio would help and is cheap. (Plug reading) Plugs are cheap and rejecting of the carb is quick and simple as well as cheap.
A basic tune up if need be. Works wonders vs. the untuned state, since we're talking about a new to you car. A poor running engine could drive up temps easy.
 
All the above plus late ignition timing will make an engine run hot. Autolite 65 copper core for plugs is what I use.
Also buy a good quality mechanical temp gauge, OEM gauges are usually not accurate after 40+ years.
 
I pretty much have the same set up on my E Body, no shroud, fixed fan, on a 110* day it doesn't get over 180, something is not right, like others have said, check AF ratio, timing etc, I dont have AC so nothing is in front of my radiator btw.
 
I have a few thoughts:
1. I tried an electric fan setup. Even with a shroud, it never cooled as well as I would have liked. I wound up going back to a Stock fan and shroud setup. Along with 2, and 3, I am OK now.
2. You need to make SURE you have a good hood to radiator seal in the car. I notice that that seal is missing in most of the Mopars bodies I see. That will help force more air through the radiator. Also, if there are any gaps between the fan shroud and the radiator, you should seal them. Every little bit helps. Assuming your your radiator is OK, it is likely a problem with the amount of air that actually flows through the radiator.
3. I am a big fan of Royal Purple products. I put two bottles of Royal Purple Purple Ice in the radiator. Did that help? I don't know. I didn't do a very good before and after experiment, but I tend to believe that Royal Purple would not falsely advertise a product.
4. You need to buy a laser no-touch thermometer. They have gotten pretty cheap ($19.99 now at Harbor Freight). Using this tool, you can see what the REAL temp is going through the thermostat housing. You can't imagine how handy they are.
 
I have a few thoughts:

2. Also, if there are any gaps between the fan shroud and the radiator, you should seal them. Every little bit helps. Assuming your your radiator is OK, it is likely a problem with the amount of air that actually flows through the radiator.
My radiator has no shroud. Did they originally come with them?
 
Is the gauge/sender accurate?
I have no idea. I was told it was a new gauge cluster, but... the alternator gauge and dash tach are inoperable.
As suggested above, I'm thinking of installing an auxiliary water temp gauge below the dash.
 
I have a few thoughts:

2. You need to make SURE you have a good hood to radiator seal in the car. I notice that that seal is missing in most of the Mopars bodies I see. That will help force more air through the radiator.
Would you have a pic you could post of the radiator seal mentioned? My hood has no insulation above radiator.
 
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I recently towed over the mountains, 89 350 Chev overheated on first attempt. I had removed my fan shroud because it was rubbing when the truck flexed, anyway, I had to drive back home and put it on. That and adding air to the tires and no problems pulling my RV over the pass to Leavenworth. Every little bit helps but it sounds like there's more going on than the shroud to me in this case. Good luck.
 
if it is a correct 1970 10:1 340-the factory plug is a Champion N9YC, or Autolite 63. try no thermostat-it is free. on the highway a shroud or better fan is useless. boil out the radiator.
 
I've been looking around online for a shroud, and Classic Industries has one, but made for A bodies with a/c. I don't have a/c.
Cannot find one made for my car... maybe that's why seller didn't install one? I just got the car from Canada the other day, and
I guess they're not that concerned with 90+ degree days.
Description from internet:
Mopar SHROUD, RADIATOR FAN, BLACK, 22 INCH, INJECTION MOLDED, INCL DETAILS OF ORIGINAL PART, REPRO
An excellent reproduction of the 1970-72 A-Body 22 V-8 radiator fan shroud. Original part number 2998 325. Correct for all V-8 cars using a fan shroud including 318 with A/C, 340, and 360 powered Darts, Valiants, Dusters, and Demons. Injection molded with all of the details of an original part.

So it is correct for all v-8's using a fan shround including 318 with a/c, then it mentions 340 and 360 but doesn't mention a/c on those. I'm quite confused.
Does anyone have a service manual that shows a/c cars and non a/c cars used different shrouds?
Classic Industries | Restoration Parts | Mopar Parts | Camaro Parts | Firebird Parts | Nova Parts | Impala Parts | GM Truck Parts | Tri-Five Chevy Parts
Many thanks to those trying to help me figure this out.
 
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If you're running an original 22" radiator with the upper radiator hose on the driver side & lower hose on the passenger side, the 2998325 should be correct for your 340 Duster.

Here's a picture of the hood to radiator seal mentioned above which I would also recommend installing...

P1020314.JPG


P1020315.JPG
 
If you're running an original 22" radiator with the upper radiator hose on the driver side & lower hose on the passenger side, the 2998325 should be correct for your 340 Duster.

Here's a picture of the hood to radiator seal mentioned above which I would also recommend installing...

Thank you. My hoses are as you describe. I think I will order both items.
I'm not very mechanically inclined... it seems the fan must be removed to install shroud? I'm old (69) but not very experienced in car repairs.
 
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Yes, you'll need to pull the fan. It's not difficult, just tedious. I would loosen the 4 fan bolts, remove the tension on the alternator & then wiggle the fan forward. Don't hit the radiator :)
 
Also, you'll need the special clips to mount your shroud. Not the best picture--it's blurry. Sorry....

Shroud Clips 001.jpg
 
Yes, you'll need to pull the fan. It's not difficult, just tedious. I would loosen the 4 fan bolts, remove the tension on the alternator & then wiggle the fan forward. Don't hit the radiator :)

Too avoid possible damage to the radiator - take some wide blue painters tape and put on the radiator where you are working. This will help to avoid damage and also save the skin on your knuckles. Been there done that as I put a fan shroud on my 72 Duster last week and did not want to remove the radiator to do it. It's very time consuming so - be patient. :)
 
Hey Mr. Alan,
Ever get a temp reading besides the gauge? Would hate to see you go through all this trouble and expense, like I did, only to find your temp sender ($10) was bad. I figured this out after I bought a new radiator, water pump, hoses, etc..

I don't run a shroud and car maxes out at 195' in city traffic on hot days. Pretty much daily driven too.

If you check the upper radiator hose with a temp gun after car is completely warmed up it should tell you close to your temp. Worth a try before you go "all in" (like I usually do). And you get to keep a useful and neccesary tool.
 
Hey Mr. Alan,
Ever get a temp reading besides the gauge? Would hate to see you go through all this trouble and expense, like I did, only to find your temp sender ($10) was bad. I figured this out after I bought a new radiator, water pump, hoses, etc..
I don't run a shroud and car maxes out at 195' in city traffic on hot days. Pretty much daily driven too.
If you check the upper radiator hose with a temp gun after car is completely warmed up it should tell you close to your temp. Worth a try before you go "all in" (like I usually do). And you get to keep a useful and neccesary tool.
No, just the reading on the gauge.
Someone above mentioned Harbor Freight has them for $20. I will probably buy one of them, as I would have very little need for it after this project.
But I want to get the shroud and seal anyway because I want to keep the car looking original.

duster340_zpscq4trswl.jpg
 
Can I find these at Home Depot or auto supply store? Are they called J clips?
I remember having a small package of these but am unable to find them, now that I need them!

You could probably find clips that will work fine for the shroud at 1 of those stores....However, If you want correct clips, I think you'll have to buy them from 1 of the aftermarket suppliers. You could also place a Wanted Ad here on FABO.

Or keep looking for yours :)
 
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