New to site, new to Mopar overheating issues

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Yeah and it has an overdriven pump because of the pulley difference because of packaging conciderations. The FSM stated also it's got a 6 blade pump. That ain't overdriven if it's got less blades on the pump than a non A/C pump. Its flowing the same amount of coolant by virtue of 2 less fins than a non A/C pump. If you want your 73 truly overdriven, you add a non A/C 8 bladed pump to your A/C pulley setup that has the smaller water pump pulley
 
Wyrmrider said:
fans (and headlights) should be put on relays and not have power going through dash and ammeter, key or headlight switch
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Thanks, I'm going to remove the electric fan and check into all the other things. I hope I didn't screw something up when I ran the fan on the F side of the alternator regulator because now I can't get any power through that side.
 
moparmat2000 said:
Yeah and it has an overdriven pump because of the pulley difference because of packaging conciderations. The FSM stated also it's got a 6 blade pump. That ain't overdriven if it's got less blades on the pump than a non A/C pump. Its flowing the same amount of coolant by virtue of 2 less fins than a non A/C pump. If you want your 73 truly overdriven, you add a non A/C 8 bladed pump to your A/C pulley setup that has the smaller water pump pulley
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Look again. The 318 AC and the 340 have the same number of blades.

It’s in the book and yet, you STILL argue.
 
Look again in your 1973 FSM 318-340 have same number of blades only on the air conditioning ones. 6 It's in your FSM. I just looked. 318 non A/C shows 8 bladed pump. 318 with A/C shows 6. 340 shows 6 bladed for both non A/C and A/C. Your the one talking about more coolant flow. If that's the case then why doesnt your FSM list an 8 bladed pump on the 340 with that faster pulley ratio? Probably because it's not needed.

Again he is using 67-69 non A/C pulleys. Ratio is different than 70 up 340. The 67-69 318-340 more than likely used the same diameter pulleys. It does not matter he has a 70 up water pump and radiator on his 340. He has either the wrong pump or a partially clogged or undersized radiator.
 
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moparmat2000 said:
Look again 318-340 have same number of blades only on the air conditioning ones. 6 It's in your FSM. I just looked. 318 non A/C shows 8 bladed pump. 318 with A/C shows 6. 340 shows 6 bladed for both non A/C and A/C. Your the one talking about more coolant flow. If that's the case then why doesnt your FSM list an 8 bladed pump on the 340 with that faster pulley ratio? Probably because it's not needed.

Again he is using 67-69 non A/C pulleys. Ratio is different than 70 up 340. The 67-69 318-340 more than likely used the same diameter pulleys. It does not matter he has a 70 up water pump and radiator on his 340.
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Ok. You are just TOO STUPID to deal with. It’s whatever you say.

Listen moron, when the FACTORY wanted maximum cooling THEY overdrive the water pump.

The reason they underdrive some of them is because it does take more power. Not much, but some. So on the underpowered stuff like the /6 they slowed the WP down.

I’m confident you’d argue with a stop sign.

EDIT: they even used OD pulleys on the 225, both AC and non AC. Maybe you should get on the phone with someone like Stewart Components, who manufacture high flow water pumps and other cooling products and ask them about pump speed, coolant flow and impeller size and blade count.

No, don’t do that. You may learn something.
 
I'll join the fray. My advice to the OP is approach this systematically. Regardless it needs a good clutch fan and shroud. Verify that it is actually getting hot, if it is I'd drain and flush the cooling system. If the radiator is gunked up have it boiled and rodded. If the cap is suspect replace it and as other have mentioned a good high flow thermostat. Verify it has the correct 8 vane water pump on it.

IMHO if the pulley ratio makes or breaks the cooling system your system isn't sufficient and this is why I say that. My 434" small block is cooled with a FlowKooler water pump, a generic two core aluminum radiator from a local roundy round speed shop and a Stant Superstat 160° high flow thermostat. A MP viscous fan kit with a factory shroud that I cut down to fit. For the pulleys, the crank pulley is only 5" driving a 7.25" pulley on the water pump.

Last Friday I drove it to my front end guy to have it aligned, it was in the mid 90's and the hottest it got was 175°. I run some heads up street car stuff and at one track they hot lap us and you cant shut the car off or you are disqualified. After three or four rounds it'll be 180°.

Tell me again why I need to overdrive my water pump.
 
D's Nuts and Bolts said:
Hello,

First post on the site, however I've already been using all the great information. I bought a 68 Barracuda convertible a couple of weeks ago and it needs some attention. One issue is that the car is overheating, when it's 90+ here in Kansas. Based on the vin the car was an original 6 cylinder car, but along the way someone put the 340 in it. The guy I bought it from owned the car for 2 months (small time deal in everything guy) and knew nothing about the car and any work done, just "drove it cause it was cool."
So here is the cooling set up:
- Fan with a broken shroud
- Electric Fan, on the grill side, that's wired wrong, drawing power from the alternator resistor with no regulator or temp sensor. It wasn't working, I had it running but now there's no power coming from the resistor FLN side now (separate issue) where it was wired into.
- First noticed the issue when I drove it home after buy it, was running about 3/4 of the way up the temp gauge then got one mark from the H so I pulled over. I tried running the heater but that doesn't seem to help.

I was going to get the stuff to fix the electric fan, but am wondering if I just get the shroud and original setup running right it might be best. Any help would be great, thank you.

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Ah the great Mopar cooling debate rages on everybody has to get their licks in.
Yr and Moparmat you are both correct with your over/under drive comments.
I will throw this in to the mix.
Not to long ago I spoke with a Engineer at Griffin about this very subject and he stated that" there is no way you can create too much flow through a radiator with an automotive water pump it would have to be very extreme"
Take it for what it is worth.
 
I've run 6 blade and 8 blade pumps on my 340 , made no difference , both ran at the same temps . should not make a dif as long as your rad and thermostat are in good working order , cap as well
 
Maybe start with the simple things first.

To the original poster - Yes, hard to find real high flow 'stats locally. I have read multiple post on the 'new about the Mr Gasket brand high flow ones failing in the closed position. Not good. The Robertshaw brand ( a name from commercial HVAC devices, controls and pneumatic systems, way back ) has merged with EMP/Stewart. You get what you pay for.....


EMP Stewart High Performance Thermostats 305
 
First off, where in Kansas are you??

I had issues with my /6 last year. It ended up being the thermostat. (because I didn't have one) Test it on your stove before putting in the car - this has been my year of buying brand new thermostats that didn't work! It's funny - for those failsafe ones to work, first they must open LOL

If you want to test the radiator, there is a radiator shop in Park City (near Wichita) that can test it and repair it for a very reasonable price. Also, make sure your system is pressurizing. if not, then it will boil all your coolant out and cause air traps.
 
I dunno yellow rose you must not be able to understand your own FSM. I mean your the one that entered it into the fray, so I'm playing by your rules on this. According to YOUR FSM All 1973 A/C equipped 318s and 340s regardless of heavy duty cooling equipped or not ALL had a 1.30:1 pulley ratio and a 6 bladed pump. All 340s without A/C regardless of heavy duty cooling equipped or not ALL had a 1.20:1 pulley ratio and the same 6 bladed pump It's all in black and white. The only oddball as far as pulley ratio is the 318 non A/C with a .95:1 pulley ratio and an 8 bladed pump.

So let's go back to your HD cooling 340 on this very page your showing off. According to your 1973 FSM. It didnt matter if your 340 had heavy duty cooling or not, the pulley ratio and number of pump blades was still the same 6 blade pump for non A/C at 1.20:1, and the same 6 blade pump at 1.30:1 for A/C. And the way this reads is that this part of the engine is unchanged weather it had heavy duty cooling or not. What was likely the only different things in a heavy duty cooling package was the size of the radiator, possibly the fan diameter and number of blades.

This was likely to keep it simple on the assembly line. Engines were built in one place, car in another they built 1 type of 340 with A/C one type without. Both had pulleys and water pumps specced for if they had an A/C compressor or not. When they were put in the car, a bigger radiator was added, maybe different thermostat, bigger multibladed fan, etc. Again I am going by your FSM page. 340 standard and 340 HD cooling used the same pump, same pulleys. So if that's the case how is it a heavy duty cooling package then? Aaaah the answer lies in The optional factory installed bigger radiator. This is done this way because it's a cheap way to add heavy duty cooling on the assembly line.

So looking at all that, you could take your stock 73 340 pulley setup and increase your flow with a 318 non A/C 8 bladed pump, and yes he probably could use some 73 340 non A/C pulleys and increase the ratio. That's if he can find them, or know for sure the diameters, part numbers, what they look like etc. However we dont know yet what's wrong with this thing. Obvious **** first, radiator. Is is sized right, is it partially plugged? After that does it have the right pump for the pulley ratio. With whats currently on there it should have an 8 bladed pump.

Since he does NOT have 1973 pulleys on the engine. His are 67-69 318-340 therefore you need to size the pump to go with the ratio that's on there. 8 blade non A/C pump. Being that both HD and standard cooling for 1973 340 in your FSM show same pump, and same pulley ratio for HD and standard cooling, then like they say in Texas "that dog dont hunt". And your theory doesnt hold water either unless your suggesting an 8 bladed pump and running the larger HD radiator on your A/C equipped 73 340 ya got.

I have not been rude to YOU up to this point however, as far as arguing with a stop sign goes, you sir are obviously the stop sign I have been arguing with. Maybe you should get on the line with Stewart Components yourself and they can show you how to read your FSM. Make sure they know your talking about stock stuff. Oh yeah that's right, nevermind, maybe you might learn something.

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My understanding of heavy duty cooling vs standard cooling is that heavy duty cooling added a shroud, a more bladed fan, and a larger capacity radiator, which could be a physically larger (wider) core, and/or an extra row (or two) of tubes. The pumps stayed the same if the pulleys stayed the same. You can add a fan clutch to a non-A/C car if you want. To me it reduces air flow at low speeds and just adds one more thing to fail eventually. I prefer to use a rigid fan for max air flow at low speeds. I'll accept the slight HP loss. At higher speeds, a fan of any type isn't even needed. Ram air does the cooling. If you have A/C, eliminating the fan clutch can cause a belt squeal problem in many models. (been there, done that). It's all about the ratio, fan drag, and belt tension. I also prefer 180 degree thermostats for many reasons. 194's increase the underhood temps too high for my liking. I would rather not BBQ all my wiring and hoses. Doesn't hurt the engine however. 160 is just too cold to get the heater to work correctly and sometimes the engine just doesn't get up to it's proper running temp. That used to cause engine sludge (not so important today with our better oils), but, it can still allow moisture and other contaminants to build up in the oil. 180 just seems to be a happy medium. You can argue all you want about "no such thing as too much flow", but, as Loggato just mentioned, and what I've discovered over the years, you can have too much flow. If you just look at what they do in race cars. No thermostat is used, BUT, you have to put in a restrictor washer in it's place to REDUCE flow. Coolant needs time in the radiator to transfer heat. It's that simple.
 
moparmat2000 said:
I dunno yellow rose you must not be able to understand your own FSM. I mean your the one that entered it into the fray, so I'm playing by your rules on this. According to YOUR FSM All 1973 A/C equipped 318s and 340s regardless of heavy duty cooling equipped or not ALL had a 1.30:1 pulley ratio and a 6 bladed pump. All 340s without A/C regardless of heavy duty cooling equipped or not ALL had a 1.20:1 pulley ratio and the same 6 bladed pump It's all in black and white. The only oddball as far as pulley ratio is the 318 non A/C with a .95:1 pulley ratio and an 8 bladed pump.

So let's go back to your HD cooling 340 on this very page your showing off. According to your 1973 FSM. It didnt matter if your 340 had heavy duty cooling or not, the pulley ratio and number of pump blades was still the same 6 blade pump for non A/C at 1.20:1, and the same 6 blade pump at 1.30:1 for A/C. And the way this reads is that this part of the engine is unchanged weather it had heavy duty cooling or not. What was likely the only different things in a heavy duty cooling package was the size of the radiator, possibly the fan diameter and number of blades.

This was likely to keep it simple on the assembly line. Engines were built in one place, car in another they built 1 type of 340 with A/C one type without. Both had pulleys and water pumps specced for if they had an A/C compressor or not. When they were put in the car, a bigger radiator was added, maybe different thermostat, bigger multibladed fan, etc. Again I am going by your FSM page. 340 standard and 340 HD cooling used the same pump, same pulleys. So if that's the case how is it a heavy duty cooling package then? Aaaah the answer lies in The optional factory installed bigger radiator. This is done this way because it's a cheap way to add heavy duty cooling on the assembly line.

So looking at all that, you could take your stock 73 340 pulley setup and increase your flow with a 318 non A/C 8 bladed pump, and yes he probably could use some 73 340 non A/C pulleys and increase the ratio. That's if he can find them, or know for sure the diameters, part numbers, what they look like etc. However we dont know yet what's wrong with this thing. Obvious **** first, radiator. Is is sized right, is it partially plugged? After that does it have the right pump for the pulley ratio. With whats currently on there it should have an 8 bladed pump.

Since he does NOT have 1973 pulleys on the engine. His are 67-69 318-340 therefore you need to size the pump to go with the ratio that's on there. 8 blade non A/C pump. Being that both HD and standard cooling for 1973 340 in your FSM show same pump, and same pulley ratio for HD and standard cooling, then like they say in Texas "that dog dont hunt". And your theory doesnt hold water either unless your suggesting an 8 bladed pump and running the larger HD radiator on your A/C equipped 73 340 ya got.

I have not been rude to YOU up to this point however, as far as arguing with a stop sign goes, you sir are obviously the stop sign I have been arguing with. Maybe you should get on the line with Stewart Components yourself and they can show you how to read your FSM. Make sure they know your talking about stock stuff. Oh yeah that's right, nevermind, maybe you might learn something.

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Dude, we get it, you are beat'n a dead horse.
I am confident that the OP has a grasp on which way to go.
What a way to break in a new member, we'll be lucky if he/she every posts again.
 
cudamark said:
My understanding of heavy duty cooling vs standard cooling is that heavy duty cooling added a shroud, a more bladed fan, and a larger capacity radiator, which could be a physically larger (wider) core, and/or an extra row (or two) of tubes. The pumps stayed the same if the pulleys stayed the same. You can add a fan clutch to a non-A/C car if you want. To me it reduces air flow at low speeds and just adds one more thing to fail eventually. I prefer to use a rigid fan for max air flow at low speeds. I'll accept the slight HP loss. At higher speeds, a fan of any type isn't even needed. Ram air does the cooling. If you have A/C, eliminating the fan clutch can cause a belt squeal problem in many models. (been there, done that). It's all about the ratio, fan drag, and belt tension. I also prefer 180 degree thermostats for many reasons. 194's increase the underhood temps too high for my liking. I would rather not BBQ all my wiring and hoses. Doesn't hurt the engine however. 160 is just too cold to get the heater to work correctly and sometimes the engine just doesn't get up to it's proper running temp. That used to cause engine sludge (not so important today with our better oils), but, it can still allow moisture and other contaminants to build up in the oil. 180 just seems to be a happy medium. You can argue all you want about "no such thing as too much flow", but, as Loggato just mentioned, and what I've discovered over the years, you can have too much flow. If you just look at what they do in race cars. No thermostat is used, BUT, you have to put in a restrictor washer in it's place to REDUCE flow. Coolant needs time in the radiator to transfer heat. It's that simple.
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No stat - that is in a racing application, it makes sense.
We are talking a street application
 
But, the potential problem and solution are the same principal. The flow has to be in the proper window. Too little or too much and the cooling system won't work correctly. Add air flow variables and it's a wonder they cool properly at all! :lol:
 
cudamark said:
But, the potential problem and solution are the same principal. The flow has to be in the proper window. Too little or too much and the cooling system won't work correctly. Add air flow variables and it's a wonder they cool properly at all! :lol:
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Thank the Lord for pressure.
 
Loggato said:
First off, where in Kansas are you??

I had issues with my /6 last year. It ended up being the thermostat. (because I didn't have one) Test it on your stove before putting in the car - this has been my year of buying brand new thermostats that didn't work! It's funny - for those failsafe ones to work, first they must open LOL

If you want to test the radiator, there is a radiator shop in Park City (near Wichita) that can test it and repair it for a very reasonable price. Also, make sure your system is pressurizing. if not, then it will boil all your coolant out and cause air traps.
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I'm in Manhattan. What thermostat did you wind up going with?
 
I'm going to check all of these things starting with cleaning rad, checking the thermo, getting the right fan and possibly shroud and clutch. I might just go ahead and pull off the pump as well to see what blade it is. My guess is that the previous owners were having cooling issues, wired on an electric fan and thought.... done. Always amazes me how someone can do things to these beauties without doing their research.
 
D's Nuts and Bolts said:
I'm going to check all of these things starting with cleaning rad, checking the thermo, getting the right fan and possibly shroud and clutch. I might just go ahead and pull off the pump as well to see what blade it is. My guess is that the previous owners were having cooling issues, wired on an electric fan and thought.... done. Always amazes me how someone can do things to these beauties without doing their research.
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I must ask, do you know for sure how warm it is getting? Replace the cap if you can't have it tested.
 
D's Nuts n Bolts theres a fabo member that I know who lives in Manhattan Ks. He is restoring a 69 383S car.
 
toolmanmike said:
I must ask, do you know for sure how warm it is getting? Replace the cap if you can't have it tested.
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I don't and I must have gotten rid of my temp gun because I can't locate it.

So the two times it got really hot on the dash gauge is when I was driving it back after I got it, mostly interstate, and when the wife and I took it into town. Typical stop light stuff, but open road as well, even though we were doing 60 the temp keep going up. It will run between half up the gauge to 3/4, then start to climb to the H. The dash and everything still has the stock look and looks really nice, so I hate to hang aftermarket gauges. The suspect part to me was it stayed steady mostly then continued to rise.
I'll see if I can borrow a gun possibly.
 
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