289 over heating

Michael J

New Member
Aug 30, 2020
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Boston
I have two mustangs a 65 and 67 both with 289s and both over heat, now I do live in South Central Texas
both rebuilt with aluminum radiators 1 with 2 row 1" tubes the other has 4 rows, both have 6 blade flex fans about a 1/2"
from radiators. Both have aluminum air gap intakes with water jackets front and rear, thermostats open at 160
they have Petronix flame thrower igniters and coils I, II plugs are AC Delco R83TSZ. No wild cams, headers out thru duals
I have not a clue, any guidance would be great.
Mike
 
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Yeah, I missed the flex fan thing :doh: they are about the worst, jmo though.
Carry on, don't mind me, I'm just passing through.
The shroud question was legit though. :nice:

To OP:

Check your timing, both base and overall. How far was the engine bored over? Were the heads milled or block decked? What kind of pistons are you running? Was the block magnafluxed and hot-tanked? Have you tried a 180-degree thermostat? Are the head gaskets installed the correct way? Are you running 87 or 93 octane?
 
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The shroud question was legit though. :nice:

To OP:

Check your timing, both base and overall. How far was the engine bored over? Were the heads milled or block decked? What kind of pistons are you running? Was the block magnafluxed and hot-tanked? Have you tried a 180-degree thermostat? Are the head gaskets installed the correct way? Are you running 87 or 93 octane?
1 engine was not bored at all valve job Normal no big performance other than the ignition stuff. The second engine was bored 40 or 60 I don't remember it got an RV cam and the ignition change. Man it's frustrating.
 
Here's some stuff for chronic overheating, nothing special, just food for thought:
  • Verify the accuracy of your gauge with an IR temp gun aimed at BOTH sides of the thermostat. I recently changed sending units and the new one read MUCH higher on the gauge than the old one. The IR temp gun still read 175 degrees with both.
  • Use the temp gun to measure temp at the front of the heads as well, should be comparable to engine temp.
  • Use temp gun to read individual cylinder temps, at idle expect to see 300 degrees - 500 degrees and variations between cylinders is nothing to get excited about, but you're looking for a dead cylinder.
  • The more timing your engine can stand, the cooler it will run. Connect the vacuum advance and set it about 34 degrees at 2700 rpms. Disconnect the vacuum advance (plug it off as well) and it'll likely be around 10-12 degrees.
  • I know electric fans are the best for airflow, however my '68 has sat in 105 degree traffic and never gotten overheated with a stock steel fan and no shroud. If it has a fan, it's likely a good enough fan.
  • Head gasket orientation: not all Ford head gaskets are marked "Front". If they aren't, always remember the hole goes towards the back, otherwise coolant only goes to the front pair of cylinders and never makes it to the rear of the block.
Hope this helps,
 
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Today Saturday I timed both of my cars 65 and 67 same engine set up in both customized the shrouds to be deeper
moved the fans as close as possible. Started them up at the same time (out door temp today 70 + -) wen in the house
made some coffee and went back out. Both engine temps were above 220 -230 immediately shut them down and the 67 made a lot of noises
then thru up all over the floor. Took the 65 out for a road trip at the slow speed it was hot at 60 + steady 160 perfect.
When I got to a light and stopped the temp started up then started moving again and down to 160.
I'm now told I need a clutch or a electric fan and even some say go back to the one ford made with the car.
HELP
 
When did this start? Was it a slow build up, or was it after changing things?

A stock fan and thermal fan clutch is a lot better than a flex fan. On a flex fan, there is no clutch to wear out, but they are noisy, always sucking power and not as effective.
And a coolant recovery/overflow tank is cheap to add to both if you do not have them.

But this last post sounds like a bigger problem with airflow or water flow. Pics will help like already said.
Looking for cheap answers - do the lower radiator hoses have coils do they do not collapse? How do you know the thermostats open?
I have known about people who accidentally put a reverse rotation or regular rotation water pump on 302’s and 350’s, but I cannot see that happening twice easily.
 
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I'm back in', I tried some timing first and the 67 as it sat for 20 min only went to 200 and I got to watch the coolant flow by in side the cap.
Although after a short drive it stayed below 190 but when I got back to the garage and sat running it did warm up over 200.
With the 65 I did the same timing adjustment and let it sit and run went to 190 and stayed. With this radiator I got to see the coolant flow but It took
more time to reach the flow temp.
The 67 has always been hot w/ ac on sitting stopped in south Texas traffic jamb, just turned the ac off.
I thought I sent out some photos I'll have to look for them.
Thank You for your continued support.
M
 
I know this might sound crazy but hear me out. On my 68, when driving, I was good. In traffic it would climb. I have a 3 core radiator, dual electric fans, everything look good. I live in Miami so its hot but I was wondering why it would overheat.

One day on a short drive from the store, I noticed the steam and smoke...car looks like it wanted to blow. I noticed my cap....It looked ...wrong ?? Cannot describe it. I taped it and boom ! It geisured on me. Stuff everywhere. The water looked really nasty, I was at a lost. Well after it all cooled, I put the cap on and noticed It did not seem to seal. It was sealing but it still seemed off.

After some research I discovered that some caps have different PSI ratings and for the Ford SB's, 68 we need the 13 PSI release caps. I went out and bought a nice cap with the release valve on it, and the correct psi. Fit like a glove. I flushed my system and put in new coolant. Problem solved. I have not even come close to overheating again. I was out in what was 104 temps, in traffic, and she ran as cool as ever.

I would have never thought the cap would be the issue, but it was. Just a thought.
 
plain and simple not enough fan flow while not moving.....get rid of the damn flex fans !
I'm easy out they come and with luck I have a new 3000cfm and a new fitted shroud so I'm doing the 65 tonight and going to order the 12" shroud for the 67 and I have a second 3000 cfm fan on the shelf, but one at a time. I'll keep every one posted. Now if a 3000 is not enough let me know tonight. Also it's a tight fit to the water pump pulley bolt heads any advice there?
M