Carl Davey, specialist Subaru Impreza parts supply

Manifold Insulation Spacers (10mm)
Subaru Impreza

These 10mm spacers are manufactured from Tufnol Carp, a material that has a very low heat transfer coefficient. Fitting these spacers between the cylinder heads and inlet manifold of your Impreza is a great way of reducing heat transfer from the heads to the manifold. This helps reduce charge temperatures which increases the density of the air improving engine performance.

The spacers are CNC machined and incorporate locating dowel ports to ensure correct alignment between the cylinder head and inlet manifold where dowels are fitted. Longer stainless steel bolts are also included along with washers.

The spacers fit all Subaru Imprezas manufactured between 1992 and 2010 but please detail your specific model year when ordering to ensure the correct style of spacer and length of bolts are sent. I highly recommend fitting these in conjunction with a pair of Head Tank Insulators.

Note: these are not gaskets, hence an OEM gasket must be used on both sides of each spacer (see picture 4). The Subaru part number is S14035AA281 for MY92-98 cars and S14035AA421 for MY99-10 models.