OVER HEATING AT IDLE

Technical Discussion on Pre-1973 Mustangs

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123abc
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OVER HEATING AT IDLE

Post by 123abc »

I have a 351c that has no other heating issues to speak of except 1 when it idles a lights after about 4 or 5 sets it will start to climb on the needle even when the thermos kick in . but it will come down when you start to move could the cam I have in it be doing this as its being run advanced on the timing chain

HYDRAULIC - Fair idle with lope broad power band
in street engine with minimal modifications. Low
valve lift suitable for single stock type springs.
BASIC RPM 2100-5000
Street
Strip CD219-52A part number 972803 C35-16
99280-16
218
228
290
300 114 .000
.000
.509
I am also running a I think a 180 thermostat its not running lean
I thought maybe the exhaust side of things may not be clearing adding to engine heat
I did have a blue racer part num 972836 before this any thoughts
Last edited by 123abc on Tue Nov 14, 2017 5:50 am, edited 1 time in total.
Husky65
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Re: OVER HEATING AT IDLE

Post by Husky65 »

What fans are they? A lot of the thermos out there are crap.
When you say it comes down after moving, are you talking moving as in 20-50kph or 60-80+kph?
If it's the latter, it points to a fan. If it cools down driving at low speeds, could be a crappy water pump that isn't flowing enough at idle.
Last edited by Husky65 on Tue Nov 14, 2017 5:57 am, edited 2 times in total.
hybrid
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Re: OVER HEATING AT IDLE

Post by hybrid »

Yep, I'd be suggesting the fan setup, or water pump. Idle is the time your water circulates the slowest, and obviously you're getting no assistance from airflow from the car moving.
I've got a high flow thermostat sitting on the shelf I am going to put in mine at some stage.

Not that mine overheats.
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

it never used to heat up worked fine with the twin fans I have on it seemed to start with the new cam the pump is a cast iron one come to think of it it did heat up a little which is why I put the fans on in the first place do yeah maybe pump but looks to be moving a fair bit of water at idle though
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

wonder if a couple of vains blocked in rad
lukep6470
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Re: OVER HEATING AT IDLE

Post by lukep6470 »

Can you post a photo of your fan setup? Are they sitting flush on the radiator or is there a gap?

I'm using 1 big electric fan on my 67 and it copes with 35+ days quite happily. It's the biggest fan I could fine to fit and I had to trim the shroud to make it sit flush on the radiator. I got stuck in hellish traffic at Redcliff last summer, it was a brutal 37 degree day and sat for 15-20 mins in stop start traffic after coming off the motorway no problem.

What sort of coolant are you using? I would've though if you had a blocked rad you would be overheating at speed as well.
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

I have 2x 12inch fans side by side against the radiator no gap it is the orig pump I think being cast iron and doent need much movement to keep cool just not sitting usig concentrate coolant same ive always used
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

I might just replace the pump and fans good place to start
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

any advice on a pump brand and a fan brand that's good
hybrid
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Re: OVER HEATING AT IDLE

Post by hybrid »

What size is your radiator?
I've put a huge single BF fan on mine, which includes the shroud and it works great.

Image
Shaunp
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Re: OVER HEATING AT IDLE

Post by Shaunp »

Flow cooler pump high volume
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

24 inch 3 or 4 core
Dwayne
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Re: OVER HEATING AT IDLE

Post by Dwayne »

It may sound silly, but have you checked the fans are pulling air through the correct way?
123abc
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Re: OVER HEATING AT IDLE

Post by 123abc »

yes

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Dwayne
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Re: OVER HEATING AT IDLE

Post by Dwayne »

Had to ask because my mates car had them mounted like that, but the wires were reversed and it was pushing the hot air forward. He only worked out the problem when a bit of paper dropped behind the fans and sucked it up against them.

A shrouded BF fan like Hybrid's would fit nicely and draw cool air through the whole radiator (instead of just where the fans are).
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