Overheating question

[MikeStang 247]

I know 200 is not overheating, but around 200-210 the car starts to run bad, and wont hardly idle..

at around 210 most older cars seem to have a hard time of it.

I have lived in texas and louisiana all my life and have never had overheating at idle problems with my older cars, usually problems with overheating while moving.....and i dont plan on having my cars run over 200.

But if you can explain to me how to get the car to idle and run correctly at 200 plus im all ears....it seems to have no problems with running right below 200.....

And i dont plan on putting heat sinks, spacer under the carburetor, or even a heat block plate under the carb....As it didnt have all that shit when it was new so why should it need it now :-)

But once again if you can tell me how to make it RUN Correctly when its 200 plus please clue me in, because if the 4 core radiator dont fix it then im going to need other avenues of approach, but i dont see that as being the case but i like to always be prepared.

Mike

[sleek98 12]

Does the car have a factory carb? I spent most of friday going to des moines at 210-215 (it was about 100 outside). I didnt have any issues with the car idleing, it did take about 10-15 seconds longer to start. When the temps dropped back into the low 90s and below the car would sit on 200 no matter if im crusing at 75 or sitting in a parking lot. Also is there any exhaust leaks in the manifolds?

[MikeStang 247]

Nope, no exhaust leaks, carb is original 2 barrel that I rebuilt, and in my opinion it's a bit on the rich side, but have set it rich and lean and it makes no diff at idle.....cruising she stays 180.....idle she climbs on up....don't wanna see how high tho, but like I said once temps climb, the car won't hardly start.....

[sleek98 12]

Ok I have the same carb setup and I have to crank it over for like 30-40 secs after it has warmed up but it usually fires up if i dont give it any gas. Its better than my dads 67 gta with the 390 4 barrel setup. I wonder if it is boiling the gas out of the carb and upper fuel line causing it to not want to start.

 

Did switching it over to the 24" 4 core radiator make any difference?

[Max Power 74]

Ok I have the same carb setup and I have to crank it over for like 30-40 secs after it has warmed up but it usually fires up if i dont give it any gas. Its better than my dads 67 gta with the 390 4 barrel setup. I wonder if it is boiling the gas out of the carb and upper fuel line causing it to not want to start.

 

Did switching it over to the 24" 4 core radiator make any difference?

 

 

Usually that the fuel pump not bleeding pressure back and forcing the remaining pressure past the needle and seat once the car is shot off, causing flooding. A really common problem.

[LSG 15]

MikeS, what engine is in the car ? Where does the engine get its intake air from ? It sounds like you're boiling the gasoline in the carb's float bowl while you're idling. You may well need to block off the heat crossover under the intake, if you have that, and insulate the fuel line, and put a spacer under the carb, a heat block plate or a turkey pan would be even better. Why might you need all this extra crap when the car did just fine when new and it didn't need so much help ? Largely because the hydrocarbon stew we call gasoline is very different now than when our cars were manufactured. Because we have concerns about evaporative loss and most things are fuel injected now, the chemical mix is far less than ideal for an older car with a carb. You can try different brands of gasoline and see if any of them do better than what you have now......but keep in mind that 'gasoline' is a different blend every month, and what you purchase in Louisiana is different than what I get in Michigan. The idea is that the blend will be what you need for your weather and location. But because all of the new stuff has F.I. , and the fuel injection returns whats not needed to the fuel tank, our deadhead carb systems just aren't as happy as they used to be, but we are few enough in number that fuel distillers are not willing to make special blends just for us. Since they don't really care about us, we have to adapt. Our choice seeems to be to adapt or quit driving old cars. I'll adapt. LSG

[sleek98 12]

Usually that the fuel pump not bleeding pressure back and forcing the remaining pressure past the needle and seat once the car is shot off, causing flooding. A really common problem.

 

sorry for thread jacking but what would be the fix to this problem? I put on a new fuel pump about 2000 miles ago, granted that was also 2 years ago. Thanks

[Max Power 74]

sorry for thread jacking but what would be the fix to this problem? I put on a new fuel pump about 2000 miles ago, granted that was also 2 years ago. Thanks

 

 

Replacement is the only fix, but I have had bad fuel pumps from the start on rare occasion. If you put a new one on it's probably boil or leaking carb shafts or somethings else. It might not be a bad idea to see if it even flooding while off in the first place.

 

Look down the carb after shut off and sitting a while to see it it is dripping. Pull a spark plug. Usually a flooded car starts faster when you press the accelerator to the floor and hold it there. Etc.

[miketyler 15]

Mike - I see you treating the symptoms of overheating but not addressing possible causes. Did this thing ever run cool for you? If so, what exactly changed?

 

Did you run a vacuum test and/or check for vacuum leaks? A leaking vacuum advance or power steering booster or even carb base gasket maybe? The timing is correct? All cylinders are firing strong and have good compression? Does the radiator build pressure when it gets hot?

 

My 340 Cuda behaves very much like yours and I think I could write a book about overheating issues and the things I tried to get it down to 200*. Although it's a different engine, the principles are the same. I found:

 

1. Copper brass radiators cool about the same as high tech light weight aluminum units.

2. The best air flow was from a 5-7 blade belt driven fan

3. Better with a shroud than without, ideal position places blades half way inside the shroud

4. Water wetter products reduce surface stresses in coolant and supposedly aid in better heat transfer. I have never seen these make a notceable difference.

5. Thermostats arent rated for engine operating temps; they are rated at the temp point at which they open. I interpret the temp rating then to be the minimum operating engine temp.

 

To this day I still deal with the same issues as you. I live in Texas and AC is a must. I retained my belt driven fan but the best results I got was to add a thermostatically controlled large SPAL electric pusher fan to the front of the radiator. I run this today and although I still see temps around 210*, when the fan kicks on it stabilizes and doesn't move much higher than that. I have high hopes for this 70 Mach I am restoring that it will run at a tame 190*-200* but if it doesnt, I will apply these experiences to it same as my other car.

Edited July 5, 2011 by miketyler

[MikeStang 247]

Timing is correct, found a few val leaks tha i fixed....Tried varying the timing, have not run a compression check yet, but motor runs well, and all plugs look better than i have seen in a while LOL,....BUT they are nice and tan, but i knotice that generally when you have the right heat range plug the ground strap will change color to about half way up the ground....Well this color change is in the first 10% of the bottom of hte strap....Wondering if the plug is too cold....But dont think this would contribute to the overheating.

My 4 core didnt check out, several holes in it, and beyond repair...the rad guy said keep it because some one may want it for a factory correct radiator, but he wanted 400 bucks to replace the core in it...hell for that price i can damn near buy the best aluminum on the market LOL.

5 Blade fan is half way into the shroud and pulls a good amount of air....Its gotta be the small surface area of this 2 core rad.....i have never seen a stock motor run hot like this when everything is right on it.

[stangs-R-me 120]

Last week I brought in my orig. 24" that I had re-cored with a 3-row core back in the 80's and thankfully it checked out ok.

 

Small crack in the top shell that he fixed but the core was solid ... total cost for flush, test, & repair was around $46.00.

 

He said a new core (if it was needed) would have been around $300 ... complete new radiator would have been around $200. He said re-cores used to always be cheaper, but not with the cost of copper where it's at now.

 

Doug