Silicone Hoses

Silicone hose is used for the air and coolant connections on performance engines: turbo and intercooler pipework, intake couplers and coolant hoses. It copes with under-bonnet heat and boost pressure, stays flexible, and comes in enough shapes and sizes to build your own pipework.

The listings give the inside diameter, which must match the outside diameter of the pipe or spigot, and the shape:

• straight lengths;
• couplers for joining two pipes of the same size;
• reducers and reducer bends for joining different sizes;
• bends at 45, 90, 135 and 180 degrees, and hump hoses;
• T-pieces, flexible hose and small-bore vacuum hose.

Colours are mainly black and blue, with red and clear in some sizes, and aluminium pipes and bends are available for the straight runs in between.

Choose the clamp for the joint. T-bolt clamps give an even grip on boost and intercooler joints; worm-drive clamps suit coolant and vacuum lines. A pipe end with a raised bead holds the hose far better under boost than a plain one.

Standard silicone hose is not made for fuel or oil, which break it down over time, so use hose rated for those fluids. Support long runs so they cannot rub on sharp edges, keep them clear of the exhaust, and check the clamps again after a few heat cycles, as silicone settles slightly.