[RodgerD]

I've got two 1.8 turbo with HG problems and still to decide which gasket to use. I'm going down the route of sourcing 1.4 blocks as they shouldn't have been stressed like a 1.8T engine. I'm going to make sure liner protrusion is 0.005" and siding with the elastomer gasket, possibly with blue Hylomar. Going to look at torque settings, going to test an old oil rail to decide what torque the ladder threads will take and make a judgement.

I'm also looking at keeping the coolant as close to the thermostat temperature as possible and not rise to 100+ degrees before the fan kicks in. By the time the fan cuts in head temperatures will be well above 100 degrees C. Higher coolant temperatures compared with ambient temperatures means the coolant system is less efficient at dissipating the heat around the head, so every degree nearer thermostat opening temperatures means the cooling system is more efficient. Given the low level of coolant in the system, a close control of coolant temperature at around thermostat temperature should help with the head softening.

I'm also looking at under bonnet temperatures, as this will play a part as some of the heat dissipation is from the head external surface with the under bonnet enclosure creates a heat trap. One possible way of reducing under bonnet temperatures is to remove the centre section of the double bulkhead and allowing a heat flow route out through the driver's side scuttle vent, or modifying the centre section with extra vents. It might even be worth looking at installing fans where the bulkhead panel is now to give positive under bonnet ventilation.

If the k series HG issue is going to be solved, it requires looking at not just the engine with the problem of expansion of dissimilar metals, but its installation as well.