Originally Posted by Stu @ M Developments
Its normally a plate made from a low conductive material used to isolate the inlet from heat. Many BMW's use this method as std.
I reckon on it being a manifold insulator too! We used to make loads and loads of these for lots of different cars (there were even a number of race teams which bought them)
Only ever made a few YB (all 3/4" IIRC) ones though which look like:
Most of the spacers were 1/4" thick (6.4mm): In comparison to a normal gasket at about 0.6mm thick the 6.4mm spacers would conduct between two hundred and a thousand times less heat.
