After running replacement porcelain manifolds for the past 20,000 miles during which time all the coating gradually flaked away, I had my original manifolds coated in ceramic black at Prairie Auto Porcelain. The temperature seems to be much lower than the replacement manifolds although the old ones being down to mostly bare metal probably did not help. What temperatures do porcelain manifolds tend to run after a spirited drive? After installing the ceramic coated manifolds yesterday mine were around 490F after a rather moderate run of about 25 minutes.
I came up with about the same temps on my Jet Hot ceramic manifolds vs the bare, flaked off porcelain much like you probably had.
from my notes, same manifolds, same ambient temps, same time driving, and no other changes, I saw about a 50 degree drop across all the cylinders. all in the 475-500 temp range reading right about the top curve.
Hi Drew, complications can occur interpreting temperature measurements. For example, if an infrared sensor and a temperature is indicated on a digital readout, the complication is knowing how to correct the indicated temperature for emissivity coefficient of the material measured. Infrared thermometers can be useful looking to temperature increases or decreases on the same materials. When different materials, or surface finishes, are compared with an infrared thermometer then indicated temperatures may well need corrections before comparison.
Well on my old race car a set of steel headers would get hot enough that they were burning the paint off the frame rail beside them. With Jet Coat that stopped, so it does work. On a dyno they would glow a very dull red, nowhere as bright as without the coating.