Chris'69Mach 23 Report post Posted September 29, 2014 Here re the things I have checked/done. *Note* I had over-heating issues already before I did the following. Replaced head gaskets, head bolts, intake gaskets, intake bolts, exhaust gaskets and bolts. I did all of this because I believed I had head gasket issues. And I did .... the head bolts were stretched as were the intake bolts. Good thing I had already ordered the new bolt sets. Took off the original distributer and put on a HEI distributer (looks ginormous but it cleaned up the engine bay a little by taking out the coil). Put a 3000cfm electric puller fan on. Put the "correct" thermostat in, a 180* one. Yes, it has the little hat and the restrictor plate is present in the block. Set the timing to 13* at the harmonic balancer. Burped the cooling system 3 times (just to make sure I got all the air out). Shot the radiator with a tempurature gun, 206* - 210* on outlet (top of radiator) and 168* - 170* on intake (bottom of radiator). The fan and radiator seem to be doing their job well enough. But I am over-heating no matter where I drive, either on the hi-way or country road. The engine sounds and runs fine imho. What about spark plugs? Could they be "too hot" to cause the over-heating? If so, what spark plugs should I run? Any other ideas? This is my daily driver by the way. Quote Share this post Link to post Share on other sites
69 red fastback 20 Report post Posted September 29, 2014 Just wandering if you checked the engine with a temp gun, just maybe your gauge isn't reading correct, just a thought!! Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted September 30, 2014 (edited) hello; ok, bummer, but good description how far is your engine bored? is the rad chinese? how many rows is it? exactly what fan is it? does it just run hot in traffic or on the freeway or both? your rad and/or fan are not big enough, we just need to determine what it is. a 30 degree drop from in to out is good at least. your thermostat is also open, might need a 192. it will also tun cooler if you install a water by pass block off plate. cougars sells them. then use a non cleveland thermostat. this would be the cheapest thing to try first. your plugs should be a 5 heat range on the NGK scale. . Edited September 30, 2014 by barnett468 Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted September 30, 2014 hello; ok, bummer, but good description how far is your engine bored? is the rad chinese? how many rows is it? exactly what fan is it? does it just run hot in traffic or on the freeway or both? your rad and/or fan are not big enough, we just need to determine what it is. a 30 degree drop from in to out is good at least. your thermostat is also open, might need a 192. it will also tun cooler if you install a water by pass block off plate. cougars sells them. then use a non cleveland thermostat. this would be the cheapest thing to try first. your plugs should be a 5 heat range on the NGK scale. . From what I can tell, the engine has not been bored out. I looked when I had the heads off. The radiator is original to the car. It is a 20", 2 row I believe. This is the fan I installed http://www.cjponyparts.com/flex-a-lite-electric-fan-kit-black-magic-s-blade-15-inch-3000-cfm-universal/p/FAN23/ The engine runs hot in traffic, city and hi-way driving. What is a "water by pass block off plate? And where is it installed? What does this plate do? *Note* I have had this Mustang for 2 years and have driven it to Indiana, Richmond and Ocean City with no over-heating problems in the last year. Well, except for once. I was sitting in a drive through for nearly 20 mins and it shut off as the temp got over 200*. That was on the way back from Indiana last Thanksgiving. After driving it to test the over-heating issue, when I pull into the garage, the coolant boils over. So, I know my gauge is reading correctly. Your idea of the radiator not being big enough, has merit to me and what I have been thinking. But, could it also be the spark plugs are too hot? Could it be running too lean? Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted September 30, 2014 (edited) hello; the overheating started only after you changed the parts? what about your water pump? is that 13 degrees with the dist vac disconnected? whaT IS THE TOTAL TIMING WITH THE DIST VAC DISCONNECTED? it is not because it is too lean. if it was too lean it would have big flat spots when you hit the gas pedal. it might also ping. you can get your rad water tested to see if the heads are leaking. if everything is mechanically good, you need the bypass below. you need at least a 3 row us made wide radiator or bigger chinese one. US Radiator sells them the us made ones. if it still tuns hot in traffic you need a bigger fan. there is no way that fan puts put 3000 cfm. i am extremely familiar with electric fans. a lincoln mark VIII is one of the best fans and can be had for only 150.00 the dual ford contour is also good. if you run 50% anti freeze, it will run cooler with 10% but should be increased in the winter. . .r Edited September 30, 2014 by barnett468 Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted September 30, 2014 Water pump has been taken off and cleaned up. It is still working properly. Yes, it is 13* with the vacuum advance disconnected. The total timing is at 34*. I have tested the coolant and there are no exhaust gases present. This is one of the reasons I have replaced the head gaskets and bolts. Where is this "bypass" to be located? And if I were to get a 24" 3 core aluminum radiator, would I still need to use a bypass plate Ideally, what should the radiator outlet temperature be on a 351C 4V? Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted September 30, 2014 (edited) can you drive all day on the freeway without it boikinh over? , the bypass drops in under the t stat housing .m they work but you need more than just that . 30 degree temp drop is very good . your timing is good . your prob is strange . . how wide is your rad? . . . .m Edited September 30, 2014 by barnett468 Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted September 30, 2014 can you drive all day on the freeway without it boikinh over? , the bypass drops in under the t stat housing .m they work but you need more than just that . 30 degree temp drop is very good . your timing is good . your prob is strange . . how wide is your rad? . . . .m No, I cannot drive it without it over-heating. It does not matter if it is city driving or hi-way driving, it still over-heats. I have a 20" radiator. According to the Marti report, it came with a 302 and C4 transmission. I got it with a 1970 351 Cleveland 4v. I was told it was a Mach 1 when I bought it and found out it is just a sportsroof. Quote Share this post Link to post Share on other sites
larryc94 38 Report post Posted September 30, 2014 (edited) I have a 70 351C with a 20" 3 row and 192* stat, but don't have my temp gun its at work. Been out on disability for over year. I would be looking for more than a 30* drop. Your sending 170* coolant into the motor and and adding 40* to that which about right, the 180 stat don't stand a chance. The outlet temp should be around stats rating I would be suspect of a 45 year old rad. Inspect the condition of the fins for being corroded, loose or missing. Simple test to use a small awl or pocket screw driver and lightly run across the edges of some fins, they should fold over if they flake rad ng. Drop the coolant below the top tank and inspect the tubes and inspect for corrosion, if present replace the rad. Last check and often overlooked is the first thing we do is to remove the radiator cap and put it on the bench. Could be the problem and the only way to check is with a pressure tester to confirm the true pressure it will hold. I've seen too many new ones ng out of the box. I always test a new to confirm it's good. One last thing make sure the fan is placed correctly in relationship to the shroud, about mid point of the edge of the shroud Edited September 30, 2014 by larryc94 Quote Share this post Link to post Share on other sites
barnett468 418 Report post Posted October 1, 2014 ok well your car should run a least a little hot with that rad if its over 75 degreees outside . look thru the fill hole at the top of the tubes as suggested . . if there is rust sticking out of any it is plugged. . either way its too smal . i would get a 3 row 24 inch high effeciency rad and the bypass . . if it still runs a little warm get a lincoln fan and fan controller . and the 192 t stat i mentioned but a 180 should work and i prefer those. . . fr Quote Share this post Link to post Share on other sites
LoneWolf2U 136 Report post Posted October 1, 2014 No' date=' I cannot drive it without it over-heating. It does not matter if it is city driving or hi-way driving, it still over-heats. I have a 20" radiator. According to the Marti report, it came with a 302 and C4 transmission. I got it with a 1970 351 Cleveland 4v. I was told it was a Mach 1 when I bought it and found out it is just a sportsroof.[/quote'] The rad is too small for the 351C, use a 24 inch 3 row. Temp reading should be approx. 187-189 with a 180 stat in full open position. Also have a fan shroud with fan blades positioned half I and half out for best air flow conditions. Quote Share this post Link to post Share on other sites
prayers1 153 Report post Posted October 2, 2014 (edited) I agree with M1R, get a bigger radiator, YOU HAVE NO OTHER CHOICE! I too have the 351C 4V and went from a 20 to a 24" 3 row big block radiator, make sure you get one with the bottom outlet on the driverside and upper inlet on the passenger. You also need the big block shroud. I use a metal flex fan and a bottle of Hy-Per Lube - Radiator Coolant that I bought both at O'Reillys Auto. Also a 180 thermostat from NAPA. I'm running about 180 at idle and cruising and around 193 at stop and go traffic. Also forgot- You'll need the the Big Block Radiator support mount on top of the radiator and the bottom support as well. Check my past threads, there is one addressing the radiator change and one regarding the lower supports with pictures. Edited October 2, 2014 by prayers1 Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted October 3, 2014 I agree with M1R, get a bigger radiator, YOU HAVE NO OTHER CHOICE! I too have the 351C 4V and went from a 20 to a 24" 3 row big block radiator, make sure you get one with the bottom outlet on the driverside and upper inlet on the passenger. You also need the big block shroud. I use a metal flex fan and a bottle of Hy-Per Lube - Radiator Coolant that I bought both at O'Reillys Auto. Also a 180 thermostat from NAPA. I'm running about 180 at idle and cruising and around 193 at stop and go traffic. Also forgot- You'll need the the Big Block Radiator support mount on top of the radiator and the bottom support as well. Check my past threads, there is one addressing the radiator change and one regarding the lower supports with pictures. Prayers, you have 1300+ posts. Could you possibly put a link up for your thread? I was about to ask what do I need to do the conversion from a 20" to a 24" radiator. Quote Share this post Link to post Share on other sites
'70MACH1 10 Report post Posted October 4, 2014 I too had that same radiator in mine and went to 24 4 core. Don't waste your time with a three core. It's pretty easy to fab new brackets. Quote Share this post Link to post Share on other sites
prayers1 153 Report post Posted October 4, 2014 Heres one: Need pictures of lower saddle Radiator bracket Quote Share this post Link to post Share on other sites
