Under Bonnet/Hood Heat Insulation

[eschaider]

Originally Posted by gcarm

I fitted a 180 deg F thermostat (Mr Gasket MRG-6368) and a high flow water pump (+30% flow). They have helped - maybe reduced the temperature by 5 deg F.

Next step is to put a shroud around the radiator. I had to tilt the radiator to get it to fit (seems to be quite common with Cobras). So I'm concerned the airflow is not properly penetrating the rad but going over the top.

With regard to insulation, I came across a product called 'Lava Shield', made from crushed volcanic rock. Testing shows it can reduce bonnet/hood temperature by around 20% (one test showed a reduction from 121 deg F to 101 deg F). Anyone had experience with this product?

Cheers,
Greg

Heat energy is an interesting phenomenon.

If I have a glass and pour 200˚F water into the glass, the glass and water temp will measure 200˚F, perhaps a whisker less.

If I stop, empty the glass, and then pour in 180˚F water, the glass and water temp will read 180˚F again, perhaps a whisker less. If I continue to pour 180˚F water into the glass, the temperature will not rise. The phenomenon is not additive.

When you replace your higher temperature T-stat with a 180˚F T-stat your coolant temp will fall to 180˚F. If it does not, you have another problem somewhere else in your cooling system, and that is very likely closely associated with your higher than desired operating temperatures.

If your engine runs at 105˚C as you indicate, which is 221˚F for us Imperial units guys, and you put a 40˚F cooler (earlier opening) T-Stat in but the coolant temp only drops 5˚F Your problems are not t-Stat related they are something much more serious.