AFAccord
Well-Known Member
Just picked up an H23 water pipe and H23 thermo-housing. 

Outlaw Engineering said:ThermoBlok spacers are made from a laminated phenolic composite with a thermal conductivity of 0.29 W/m*K. Aluminum on the other hand has a thermal conductivity of 150 W/m*K, more than 500 times higher. You must also remember that there is a gasket, commonly steel (20 W/m*K thermal conductivity), placed between the manifold and head. Replacing the 0.025" thick steel gasket with a .250" ThermoBlok thick spacer will conduct an amazing 688 times less heat (yes, that's nearly 70,000% reduction!).
The ThermoBlok spacer material also exhibits high stiffness and compressive strength, can withstand temperatures up to nearly 300°F, and has a thermal expansion coefficient very similar to aluminum to increase sealing capabilities.