I have to come back to this thread, to update.....................
Apparently the Morgan racers who use wrapped headers/exhaust manifold are finding that the increased exhaust gas temperature is reducing catalytic converter life, in some cases to a few hundred miles. The increased temperature is melting the innards and partially blocking the exhaust, so reducing power.
Obviously racing is a much harder test of the catalytic converter innards, and there are many different specs of cat for road and track. FIA approved cats are available for circuit use.
But this has made me nervous, so today I removed my exhaust wrap.
I'm not saying a word, but its nothing to do with the exhaust wrap.....
