Don't be fooled by aftermarket cooling systems

[BBishere2]

What is the factory spacing?

That I can't tell you as I did not measure it with the stock radiator in it.

I did find out today that with the .75" inch spacing from the radiator fins, the 17" 7 blade fan touches the top tank of the radiator. I have a 1" spacer coming to replace it which should set the front of the fan blades about 1.25" from the radiator and clear the top tank - I'll post dimensions when that is on.

 

[CanadianRR]

sorta a mute point due to the year of your posting but 205 for new vehicles? no depending on configuration of said vehicle and cooling system 180 or 190 are available. bad information there.

 

[HT413]

sorta a mute point due to the year of your posting but 205 for new vehicles? no depending on configuration of said vehicle and cooling system 180 or 190 are available. bad information there.

5 posts in 2.5 years and this is what you do with it. My Yukon runs 210 by design, but you've missed the point of the post by about a mile.

 

[CanadianRR]

congratulations buttercup for looking at my profile and being able to count, did not know this forum requires people to post daily. and a quick search shows all but two models run 195 units far cry from the 205.

did not miss the point, just do not give bad info, as a mechanic the worst thing i hear in the shop is "well the forum said this".

 

[HT413]

How'd you know my middle name?

 

[Steve P.]

There are hundreds of variables, but,,,, one that is pretty constant and makes sense to me is that if you are running a fan without a shroud, you may as well run a radiator the same size as your fan. Yes, a larger rad. will be better at speed as the wind you are creating will cool the car, but most of these cars are drivers or track cars. Either way we are sitting in lanes and at lights. This is where MOST of us have overheating issues due to cooling systems. NOT ALL, but most..

It's been years since I put this into practice on my own since wrecking my back, but I have always seen that moving the coolant too fast hurts overall cooling and those without shrouds and insulation/blocking at the radiator air inlets and at shrouds have more overheating issues than any others.

Basic rule of thumb I think is as you increase HP you need to increase volume of cooling efficiency. More power means more heat and that means having to be able to remove that heat efficiently. Then keep in mind you will also up your under hood temps and that will bring more issues. Heat soaked started and fuel system, etc.

 

[superfragl]

Cannot agree to all things in original post..
Coolant flow speed is important and should be calculated properly. Higher flow pump will create turbulence in the radiator tubes which will increase efficiency. Too much flow can create cavitation in the pump. My personal experience was very positive from increasing the flow speed and installing a high flow thermostat. It fixed overheating problems for me.
Too much timing can cause detonation, however, late timing will increase engine heat output. At least that`s my experience..
I think this is a very decent article here
http://www.hotrod.com/articles/ccrp-0707-high-performance-cooling-system/

 

[Demonic]

I'll add my experience w my Charger...
My car always ran hot on the highway w/ the A/C on, couldn't keep it on. Stock 10:1 383 4bbl motor. I found a 1967 factory 180* thermostat in an old intake. It was the large cup style. I tested it on the stove w/ a thermometer and installed it in my 383. The opening is 1/2" larger than any of the standard aftermarket 'stats. It cured my overheating problems at highway speed (3:55's).

So, are all the over the counter replacement thermostats too small of an opening for the last 40 years?

 

[Sweet5ltr]

That’s why it’s normally recommended to drill a 1/8” hole for additional flow on newer thermostats. Fan clutches must be adjusted as well, most modern clutches are set to start engaging at 190* (or higher). Meaning, you’re going to have minimal lockup prior to that temperature (causing overheating issues).

 

[mopar 3 B]

Fans are worthless on the hyway. Only reason to have one is low speed travel. That 1/8" hole lets the trapped air out of the block. Remember the water cooled block. Not air cooled.
Don't understand this continual heating problem and the need for all this after market stuff. Especially when our mopars were not designed to run hot. In fact the only ones I have ever had run hot was do to coolant loss. Once that problem was solved the heat problem went away.

 

[Sweet5ltr]

Factory cars were optimized for just that, factory conditions and low-traffic scenarios. Can't even purchase a fan-clutch OEM anymore, believing it is adjusted correctly (or as it left the factory in '1970'). This is a great overview explaining how to adjust this style of fan clutch.



For example, Mancini Racing Thermal Fan Clutch: Adjustable. How many actually adjust prior to installing?

 

[beanhead]

Factory cars were optimized for just that, factory conditions and low-traffic scenarios. Can't even purchase a fan-clutch OEM anymore, believing it is adjusted correctly (or as it left the factory in '1970'). This is a great overview explaining how to adjust this style of fan clutch.



For example, Mancini Racing Thermal Fan Clutch: Adjustable. How many actually adjust prior to installing?
View attachment 651934

Thanks for bringing this up. Most of ours don't have the little adjustment plate like the one in the video, but there's usually another notch to locate the spring which accomplishes the same thing, or sometimes another notch can be filed in the tang if there is only one...many people aren't aware of it. It helps!

 

[BBishere2]

That I can't tell you as I did not measure it with the stock radiator in it.

I did find out today that with the .75" inch spacing from the radiator fins, the 17" 7 blade fan touches the top tank of the radiator. I have a 1" spacer coming to replace it which should set the front of the fan blades about 1.25" from the radiator and clear the top tank - I'll post dimensions when that is on.

The actual .75” space works fine. It’s funny that simple arithimetic didn’t work with the fan spacers, i.e. a 2.5” space between front of fan and the rear face of the radiator doesn’t necessarily come down to 1” with a 1-1/2” spacer.

Anyway, it runs cool all the time except in extended stop and go crawling traffic so I reinstalled the electric pusher fan for those occasions.
That meant the stock 37 amp alternator needed upgrading so now there’s a 98 amp powermaster alternator with a newer style transistorized voltage regulator under the hood.

 

[mopar 3 B]

Would have to look but don't think mine are tem fans. There use to be options and temp fans were only used with AC.

 

[khryslerkid]

https://www.summitracing.com/parts/DER-17317

http://www.speedcooling.com/22-Mopar-BIG-BLOCK-HD-Aluminum-Radiator.html

https://www.summitracing.com/parts/SNN-45478

 

[Car Nut]

https://www.summitracing.com/parts/DER-17317

http://www.speedcooling.com/22-Mopar-BIG-BLOCK-HD-Aluminum-Radiator.html

https://www.summitracing.com/parts/SNN-45478

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View attachment 652141 View attachment 652142 View attachment 652143
View attachment 652144

Where did you get the fan shroud? I don't see it in the links.

 

[Sweet5ltr]

Thanks for bringing this up. Most of ours don't have the little adjustment plate like the one in the video, but there's usually another notch to locate the spring which accomplishes the same thing, or sometimes another notch can be filed in the tang if there is only one...many people aren't aware of it. It helps!

Another great article, for those that may have a 'flat plate & plunger' style of clutch fan;
http://midamericachevelles.com/tech/fan_clutch_adjust.pdf

It's a pretty overwhelming article, in the case of GM cars, the factory reproductions from GM (with a plate, no external adjustment) were being set for maximum lockup around 210* F. Would make many people believe there is a cooling problem for sure, when really, the fan clutch was improperly adjusted.

 

[beanhead]

Another great article, for those that may have a 'flat plate & plunger' style of clutch fan;
http://midamericachevelles.com/tech/fan_clutch_adjust.pdf

It's a pretty overwhelming article, in the case of GM cars, the factory reproductions from GM (with a plate, no external adjustment) were being set for maximum lockup around 210* F. Would make many people believe there is a cooling problem for sure, when really, the fan clutch was improperly adjusted.

I came across that article on one of the Corvette forums a while back, that was the first I'd learned about it...good stuff

 

[747mopar]

You guys rock and are correct within your applications and I love old school methods.
Please allow me to add that I have had very good performance from Griffin 2x1.5 core aluminum radiators combined with aftermarket hi-flow water pump and hi-flow 160 degree stat on 500+ cid engines for the street
I never saw an electric fan that cooled are well as a good old mechanical fan with a factory shroud

Because most don't size them adequately! Although I agree with most of the OP's post I 100% and totally disagree that an electric fan isn't better... hogwash!You can buy an electric fan in all sorts of cfm's... higher, lower or equivalent to the factor but an electric fan delivers it at any rpm or whenever you tell it to including at idle when it's most needed.

What I see over and over again is people buying what easily fits, is cheaper or they just don't use a shroud. I drove my car for for a few years with a mechanical fan with a tight shroud, it worked fine but would creep up to 200 degrees in stopped traffic.. no biggie. While adding a serpentine belt I upgraded to twin 10" Spal fans, haven't seen 200 degrees since. By the way I'm also running an aluminum BeCool radiator and hold a steady 180 degrees with my 456. Like I said before most problems come from a poor execution, shortcuts, skimping$$, etc.

 

[747mopar]

Wow... just realized I responded to a 6 year old post .