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cooling at high rpm ?

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matty 401 View Drop Down
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    Posted: Jul/04/2021 at 9:26am
so i went to Good Guys  in Des Moines Saturday   on the way home  car ran 190-200 at 2600-3000 rpm when i would speed up for a bit it ran cooler  but crept back up when i slowed down  i have a 3 core aluminum rad and stock fan  should i go electric as a add on ?  or just totally do away with the stock fan set up and go full electric ?  car is a 72 Matador 401 727 trans 355 rear end  thanks  in advance 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ccowx Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 9:45am
Is it water flow or air flow that is causing it to warm up? Is the issue speed related, ie air flow, or water related, ie rpm's? If you are doing a steady cruise at 60 mph but 2500 rpm's, does it heat up? 

Chris 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 9:45am
Are you using a shroud with the stock fan?
190/200 is hot????
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matty 401 View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote matty 401 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 9:50am
190-200 is not hot  and no shroud  even 2500  about the same temp  i did wind it up a bit  maybe 4500 then let out of it and the temp came down to 188 or so  but slowly crept back up to the 200 range  water pump was new in 2017 and the radiator 
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Heavy 488 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 9:57am
Fans are useless with a shroud
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 10:24am
Assuming your fan is pushing a good amount of volocity, engine should be doing well with water pump. My electric fans have integral shroud, that is done like the Contour fans, so if you do an electric fan setup, that would be your best option.

With a 3 row core radiator it should cool well enough. Though, you have less air flow (CFM capabilities through the core). It probably is a concern if thermostat is staying closed until above normal temps. Nobody asked what thermostat your running. Try bumping down a wee bit. I think stock is 160°... you may have a 180° one.

Its a balance thing. Not enough air flow with late opening thermostat will make your hot and normalized temp fluctuate.

After making my reply, I noticed the reply before mine... Wha! No shroud?
You need a shroud... the 3 row core needs some pull for air to flow. A 2 row core, can run without fan shroud on a maintained driving speed around 40 on up, with an oem grill.

Also an air pocket can do the same. I think someone had put their upper radiator hose on backwards, and had an air pocket issue. It will fit, but it keeps a high point, that bends down, to trap air, midway from engine.

Edited by 304-dude - Jul/04/2021 at 10:34am
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Post Options Post Options   Thanks (2) Thanks(2)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 10:33am
Since when is a 160 thermostat stock? Try 195.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote gtoman_us Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 10:35am
Hey, I was there at GG Des Moines as well.  Total AMC count was 21.

Now at  22 since I did not see your Matador.

200 is well within operational range on a 90* day at highway speed.  No concerns.

And shrouds do work.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Buzzman72 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 10:44am
With a 50/50 coolant/water mix and a 15-pound radiator cap, the boiling point is 268 degrees F. [Not allowing for the 15-pound cap, the boiling point of a 50/50 mix is 223 degrees F.]

So what was your initial question, again?

Remember, a 160-degree stat doesn't mean your engine will run at 160 degrees. It only means that the stat BEGINS TO OPEN at 160 degrees. And what is the AMBIENT temperature? Delta T [differences in temperature] determine how easily the heat is extracted from the engine via the radiator. Higher ambient temp means that it's more difficult to shed the heat.

It's all about Flo[w]... coolant flow, air flow. [Flo does more then sell insurance in stupid commercials, y'know.]
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2021 at 11:08am
Your temperature is not unreasonable. Fan shroud for sure would be a minimum.
Fan shroud, high flow thermostat, 3/32" hole drilled in the flange area of the thermostat to relieve any possible air trappings would be the list if your concerned.

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