Uprated High tensile Mains Bolts for Z20 Engine

This full set of high tensile steel bolts will ensure that your high power Z20's crank stays where it should be.

Come complete with instructions for fitment.

We use these in most of our Z20 builds, upto about 400hp

Colder than the standard "glow plugs" fitted by Vauxhall, ideal for fast road / track use.

Gap to around .7mm. If your ignition system can't handle this then try a new coil pack, or stop running it so rich!

Fresh pack of four.

Z20 - Cool running Thermostat - Including housing and seal

This thermostat opens at a lower temperature than standard.

The standard thermostat regulates the coolant temperature to around 90°C, with the occasional jaunt above 100°C! This is good for emissions, but not much else.

This thermostat regulates the coolant temperature to around 80-85°C, which increases detonation resistance due to decreased charge and combustion chamber temperature.

Ideally we like to re-program the fan switching temperatures too, to take in to account the lowered running temperature. This is not strictly necessary though, the fans will just work as standard.