The Stovebolt Site Forums The Shop Area General Truck Talk Thermostatic Spring with a Ceramic Coated Manifold

Hello,

I have a 235 and I want to get the exhaust manifold ceramic coated because my alternator keeps going out and I think it is because of the heat. My alternator is right above the manifold, and I tested it with a thermometer and the alternator got to 160F. My concern is the manifold will not get hot enough to cause the thermostatic spring to close the flange that put exhaust on the bottom side of the carb to warm the gas during the initial starting up phase when the engine is still cold. Does anyone have any suggestions or experience with this problem, thanks?

Mike

160F isn't really hot and certainly well within the range that an alternator can tolerate.

300F is around the temperature that an alternator starts having problems.

Your alternator should be able to run indefinitely at 160F.

You have another problem causing your alternator to fail, in my opinion.

The spring will still work with manifold coatings, none of them insulate so good the spring won't relax.

Mike Bell Check your battery voltage to see if alternator is overcharging.

If this becomes an electrical question you need to move it to The Electrical Bay.

Thanks for all the replies. I am going to go ahead and get it coated, whether that fixes the alternator problem I have been having or not, it looks good and will still reduce under the hood heat.

Don't count on on ceramic coating to reduce underhood heat much at all. If you chose a light color it would reduce the radiation component of the total heat released from the hot manifold. The bulk of the heat is released by convection (probably 95%), so you MIGHT get a 5% reduction in under hood temperature, but I doubt it.

Would exhaust manifold heat shield wrap help?

Help with the alternator problem? No.

Help reduce underhood temps? Probably, at least a little.

An aluminum shield will do a lot more to deflect heat away from the alternator than spending a ridiculous amount of money on ceramic coating. I've seen underhood temps well over 200 degrees on a summer day, so the idea that heat is causing the alternator problems doesn't make good nonsense. Try using a remote BBQ thermometer under the hood and measure the temp while you're driving down the road with plenty of air flowing- - - -it should be a lot lower. The new remote I've started using while smoking pork butts will transmit up to 90 feet, and I'm already thinking up ways to make use of it for diagnosing automotive problems.
Jerry

The better heading coatings available will help cool the manifold, but it needs to be coated inside and out. But wait, now you also need to coat the exhaust pipe because all the heat from the exhaust will now radiate out though the pipe. Header wrap will also keep heat heat in, but you will need a couple of manifolds due to the heat cracking and warping of the extra hot manifold. Headers do the same thing if when street driven. A simple air duct will do more for cooling the alternator then the coatings would.