Vintage Mustang Forums banner

heat soak 66 coupe 200 ci

5K views 22 replies 16 participants last post by  coupster 
#1 ·
having problems with heat soak, drilled holes in hood (hated to do it) it has helped with shut down heat soak but did not stop it. also have had heat boil the fuel when at freeway speeds, then traffic jam and dead stop, boils the fuel (damn ethanol) thinking of running cooler air from in front of grill to see if that helps. stock motor, Daytona carb, larger exhaust manifold (ceramic coated). engine does not overheat. any suggestions??
 
#4 ·
If you are having Heat soak on a 6 banger... You have bigger issues than you think... If you've added Headers, Dual carb and other mods, I'd look there first.. Hook up a temp guage so you can get "Real Time" readings of what's going on. Also buy on of those Digital laser Temp readers from Ebay for $10 to help you locate the main cause a bit easier.

Tony K.
 
#5 ·
1 inch phenolic spacer on top of factory spacer. Also don’t run water fro heater hose through factory spacer.
 
#18 ·
I put two 1/4" phenolic spacers, one between the intake manifold and adapter, and one between the adapter and carb. Is this overkill??? If I had to keep one, which one would I keep? with these two spacers, I'm having serious hood clearance issues, but I *really* want to make sure I minimize any risk of vapor lock. worst case, i'm looking at shelby hoods for more clearance
 
#6 ·
Are you running the metal fuel line from the pump to the carb?

I seem to recall some threads around here suggesting that the metal line retains less heat than if you were running a rubber line and might be better at preventing this sort of thing.

Just wondering here, but if you're running an aftermarket electric pump is it putting out the right pressure? How's that wired in?

And have you tried non-ethanol gas to see if there's a difference? I'm outside Tampa and I think every Wawa around here has non-ethanol available. My 200 doesn't seem to care, but if you're having problems it might be worth trying a tank full and seeing what happens.
 
#9 ·
I used to have that problem.

The easy way is to use a fuel filter with a return. Just plumb it in with a "T" back to the feed line. No need to go back to the tank. This worked for me for many years.

Also insulate any under hood fuel lines.
 

Attachments

#13 ·
+1

Also, aluminum carb spacers can transfer an incredible amount of heat to the carburetor after shutdown. I live in a mild climate compared to yours (most of the time), and my wife's 66 boils fuel from the carb after a hot shutdown. I am stuck with her car in that it has an aluminum Weber carb adapter, and I have yet to find/make a phenolic one to better isolate it from the heat.
 
#12 ·
Excessive rubber fuel line won't help as it won't let the fuel inside shed heat. Also, removing the heater hose from the carburetor spacer doesn't help either as it removes any heat exceeding your water temp (so if your manifold is 250* the coolant circulation LOWERS the temp to the carb) and warms it for better fuel atomization and prevent carburetor icing when ambient air temp is below 60*F. Lastly, the fuel filter with return tee is a stock MOPAR/AMC unit from the sixties through the eighties. Looking for one for a Fifth Avenue with a 318 will probably net you the right one. The bad part? THREE rubber line and hose clamp connections..
 
#14 ·
I had bad heat soak problems with my 289 and now am having similar issues with my 347. I have a 1 inch spacer on there now too. Ethanol free gas completely cured it in the 289 and I haven't tried it yet in my 347. I had a fast idle solenoid hooked up to a switch and would activate it when the problem occurred which helped me get in and out of parking spots-it pulled the idle up just enough to keep in running. I might put that back on the new engine.
 
#15 ·
My stock six cylinder setup runs fine in 110 degree heat. I have the water running thru a 195 degree thermostat and the stock spacer. I also use the stock phenolic spacer and stock mechanical fuel pump. Nothing jerry rigged here. I do have a three row radiator which in cool weather made it harder to warm up the car. Normal pump gas which is always 10 percent ethanol.
 
#16 ·
I would also check your timing, and definitely make sure your radiator is up to snuff. A clogged radiator will make it run hot. These 6's usually do not have an issue with heat. I am in south Texas, so we see ambient temps of 102-105*regularly. I'm running a 20 inch, 2 row, copper n brass V8 radiator. I disagree on the keeping factory spacer and the heater hoses connected, mostly due to my location. I have actually removed the hose from the carb spacer and put in a valve to close off the heated water from entering the heater core. We don't need any extra heat in the cabin. As for winter...we don't really even run the choke on most of the cars. We have a Daytona universal carb with a manual choke on the 6 cylinder car. Generally it is set to wide open. We have cold temps here for a few months, but I generally don't drive the stangs much in the winter due to it being mostly rain during the winters here.
 
#19 ·
We had an Autolite 1100 with the 1 inch spacer. We used factory air cleaner. No issues with hood clearance. Also had factory spacer in place. Do u have aftermarket air cleaner? This was on a 68.
 
#20 ·
Fran G3499 if I recall . It was actually used on Dodge vehicles
 
#21 ·
Ive looked at this issue myself and think I have come up with a pretty simple solution.

The Mopar fuel filter with a vapor return is a good idea.

Install that filter as close to the carb as possible, run the vapor return line back to the area near the fuel pump. You can use a rubber line or a prebent hard line that runs right next to the prebent supply hardline.

Insert a tee fitting in the rubber fuel line that runs between the pump and the installed hard line from the tank.

Install a small cooler between the vapor return line and the newly installed tee fitting.

Vaporized fuel will exit the fuel filter via the .060 orifice, travel down the return line to the cooler, where it will return to a liquid state, reenter the supply line at the tee fitting and mix with fresh fuel from the tank.

A cooler runs $20 on ebay, $10 for the filter, I have an extra prebent fuel line, so I think I will give this a go. The rubber line between the hardline and pump is due to be replaced anyway.
 
#23 ·
Is the log head converted for Weber or is it using adapter? I would use as much phenolic as you can get away with. I don’t have a Weber conversion on any of my cars so can’t advise there.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top