Team Synergy Coatings: Automotive Coatings for Exhaust Manifolds

Team Synergy Coatings Automotive Coatings Exhaust manifolds can either be a cast iron, factory-type manifold or a tube steel header typically used in performance applications, though they are becoming very common in OEM applications. Whether for performance or show, the corrosion protection offered by coating a manifold will extend its life as well as look nicer.

The coating is a thermal barrier, thus keeping heat within the manifold or header. There are a number of benefits for this. First, a performance benefit. By keeping heat within the manifold, the exhaust gas velocity will accelareate which reduces back pressure and reduces fuel contamination due to reversion. Second, the surface temperature of the manifold is reduced. If there is a component close to it (alternator or starter for example), it will not see as much heat as it would with an uncoated manifold. In addition, not as much heat will be radiated under the hood or into the engine compartment and thereby reduce under hood temperatures. It also reduces the amount of heat that can be drawn in through the carburetor, which is a secondary performance benefit.

There are a variety of coatings that can be used on exhaust manifolds or headers, the most popular being TCB-107. This gives a near-chrome finish, tremendous corrosion protection and is an excellent thermal barrier. On the stock side, TCB-104 looks like cast iron and is extremely popular with restorers since it imparts an original dark cast iron appearance rather than the lighter appearance that is more typical of a bead-blasted finish. If a lighter appearance is preferred use SP-310 Cast Iron Icy Grey, or mix SP-306 and TCB-104 to arrive at the proper shade. All of these coatings have good thermal stability and are good thermal barriers. Due to the porosity of cast iron it is recommended that a base coat of TCB-107 be applied first followed by a top coat of the desired finish. For tube steel headers use TCB-107 applied in a single coat 9to both inside and outside surfaces) when exhaust temperatures will not exceed 1,000oF (538oC). For temperatures above this, use TCB-106 base coat (insde and outside) with a TCB-107 overcoat or TCB-105 base coat and TCB-109 overcoat.

Where higher temperature exhaust (such as in high compression engines) where the chrome-like finish of TCB-107 is desired the exhaust should be first coated with TCB-105, baked, lightly blasted and then a layer of TCB-107 applied over it followed by a final baking and polishing. This layered coating will allow exhaust temperatures up to 2,000oF (1,000oC). To reduce the amount of heat that is transferred into the metal of the header itself coat the inside with TCB-106, an extremely effective thermal barrier. Chromed headers can be coated on their insides with TCB-108 to reduce the chance for bluing of the chrome due to heat.

The end result of a coated manifold or header is better performance, better appearance, reduced corrosion and reduced component and under hood temperatures.

Thermographic Comparison of Thermal Barrier Coatings, Insulating Heat Wraps and Bare Exhaust Systems
The accompanying article written by Joe DeMonte, a Senior Thermography Course Instructor and weekend drag racer, is an excellent example of a thirdparty verification extolling the benefits obtained through the use of metallic ceramic coatings.

Team Synergy Coatings can increase the life and durability of these automotive and engine parts: