289 overheating

Hi my name is brad i have a 65 mustang with a somewhat built 289. My dad and i put a four core rad in the car with a 16 inch electric fan. The car works grate driving down the road but as soon as i get into town the heat guage climes up past 210 and dosent stop till i shut the car off and let it cool down. If someone had any ideas on how to solve the problem that would be grate.
Thanks
Brad  

I had exactly the same problem with my built 302 in a '66 with a 4 core brass/copper radiator and 16" electric fan which was later replaced with a
17" 7 blade HD mechamical fan from Summit. Neither fan style seemed to make a big difference when idling at traffic lights. If it was a hot day and my car A/C was on the overheating problem was even worse. I went through the entire cooling system from hoses, to water pump, to radiator cap, etc. Nothing helped short of getting an expensive oversize custom aluminum cross flow radiator and cutting up my radiator support. Wasn't going there.

I decided I might have a flow restriction. I put in a 160 degree Robert Shaw Hi Po thermostat in place of the stock 180 and that helped since I was getting more flow sooner and the heat wouldn't build up as much or as fast. I then went one step further and cut the center out of my old 180 thermo so there was just a brass "donut" with the center valve missing. It was essentially an open restrictor plate that allowed max flow but didn't allow the coolant to run through the radiator so fast that it didn't have time to cool. I then put in a can of Justice Bros. radiator treatment (similar to water wetter but better) and I have been able to drive in traffic with the A/C on during hot days with the motor never getting over 200 degrees. Even cooler with the A/C off. One note about this Justice Bros. product is that it turns your coolant light blue in color. I kinda like it since I installed a clear Gano filter in the upper radiator hose to trap crud from plugging the tubes in the radiator. At car shows everyone likes the Ford blue coolant you can see in the Gano filter.

The Thermostat mod and the Coolant additive made a huge difference. Just for added insurance I went one jet size richer in my carb primary jets to be sure I didn't get lean heating. So far so good. Its a cheap fix and worth a try.
Let me kow if that helped you out too. Good luck Brad.  

nice post jbirch. just wondering how much did you find the 160 degree Robert Shaw Hi Po thermostat for? did you get it over the internet?  

No. I got it from old stock at a local Carquest Auto Parts store for about $18.
I think Mr. Gasket bought out Robert Shaw a while back so you might find a high performance unit now under that name instead. They flow better than stock style replacement thermostats.  

Hey thanks for the ideas im going to try something like that tonight so i hope it works because its a lot of cash doing old cars up and its not much fun when you cant drive them.  

Hey, I know what you mean. tell us know how things go for you. I hope you have as much luck with that overheating issue as I did.  

Well she still gets hot so i think im going to get a flow kooler water pump on it. I put in just water and the royal purple additive with a 160 t stat and it still got up to 200. So the water pump that is on it is the stock on that came on the car when we bought it. So i hop that will fix it. As far as the timeing goes what should it be on that car about 8 digrees? Something elts i just found out the electric fan i have only moves 1500 cfm and i can get a zirgo electric fan the will move 3000 cfm. so that might make a differnce.  

Hi, my name is Mike and I'm watching the progress in your overheating problem.  I've got a 1969 Mach 1 with 351W.  I run cool while driving but if I sit in traffic for more then 5 minuets it heats up to 207 degrees.  This puts  my guage in the hot range which is scary seeing the guage in the hot range.  I have stock guages that have been recalibrated.  I've done everthing from putting in a 3 core rad, 160 thermostat (not a high performance), tried 3 different fan blades (no electric, trying to keep the car as stock as possible), royal purple with no change in temp.  I haven't tried a high perfermance waterpump, it has the stock pump on it.  The prior owner says "the engine was rebuilt with a mild cam" no documentation.  The engine runs strong with the FMX trans.  It just heats up while idling.  

Try an experiment and run with no thermostat or a modified one like I mentioned above to see if the low rpm flow improves and helps your problem. At least you will know its flow related. A 1500 CFM electric fan isn't enough for a V-8 motor according to some electric fan manufacuters. I ran a 2360 CFM on my 4 core brass/coper desert radiator with shroud and it still wasn't quite enough to cool my warmed over 302 at idle. 3000 CFM would have been good. I had a buddy with a 347 stroker motor who ran a 2 core aluminum rad and a 3000 CFM with a shroud and the temp stayed at spec. The 2360 didn't cut it so he gave it to me to try on my 302. No go. Not enough. Those are some real world cases to base your decision on.
I'd go either with a 3000 CFM electric/shroud or with a big 17" factory A/C fixed blade (6 blades-no flex) mechanical paddle fan on a thermostat clutch.

Timing for a stock 289 is 6 degress BTDC. Make sure the outer ring of your balancer hasn't shifted position over the years as they sometimes will do on older units. Make sure you find TDC on your no. 1 cylinder. The balancer hopefully will read the same. If not, put a new mark on your blancer where true TDC is and go 6 degrees before that to be accurate.

Let us know how things work out. Overheating is always a challenge in vintage Mustangs. Good feedback from users is always welcomed.  

hey i am having similar issues with my 68 289. 3 row alum new pump and stat. no shroud and when i get on it it pushes fluid out the cap.??????? then it heats up. last time it did it i reved it up and looked at the lower hose and i saw it move like it was collapsing but it is a new and stiff hose. is their that much suction that it will collaps a stiff hose? this issue has been going on since its been on the road. another question i have is, is the flow going from the bottom hose to the top? and if so then the spring side of the stat goes torwards the radiator? because i have the kind that has a by pass and if it was pointed the other way it will be closed due to the water pressure. any healp would be great guys....thx  

The original factory early Mustang bottom hoses had a spring in the lower hose to prevent it from collapsing.
Coolant flows into the engine via the bottom hose and out into the radiator via the top hose. If the bottom hose starts collapsing then you won't have much flow at all.
The point of the thermostat faces the radiator. The blunt capsule faces the motor and the engine water to sense coolant temp.If the other way around it won't work right. I just hack sawed the capsule and point off so all I had left was a brass donut or restrictor plate left. My problems started to end after that since I was getting more flow sooner and heat would  not build up. Worked for me. Might for you.
Worth a try.