|The MGA With An Attitude
Carburetor HEAT SHIELD (1) -- CB-203
This little project comes from Patrick Mulholland in Australia. After installing an MGB exhaust manifold (on his right hand drive MGA), he wanted better heat shielding for the carburetors.
The MGB exhaust manifold required a bit more space, so the heat shield was re-formed to fit as desired (slightly crowned in the center). The original (deteriorated) insulation was removed, and new insulation material, about 2 inches larger than original, was pop riveted to the front of the plate and covers the entire plate, plus some extension at the bottom. (Click for larger picture). This took about 30 minutes from start to finish to make and attach. The kicker is, this is a very special heat shield material.
The material is a metal and ceramic sandwich. The outer surfaces are thin aluminized steel 0.006 inch (0.15mm) thick. The inner layer is corrugated ceramic paper 1/8 inch (3.2mm) thick. It is easily formed and cut, but otherwise quite rigid. I haven't see the actual thermal resistance numbers, but I might guess it's about the same as corrugated cardboard (which is pretty good insulation for being thin). The difference of course is that this ceramic material is heat resistant to 850dC-900dC (1500dF-1650dF). This stuff might survive even if it came into direct contact with the exhaust manifold, so the finished heat shield may look better if the insulation was attached to the back side of the plate.
Patrick claims that his vapor lock problem in hot weather has been completely banished. I will reserve judgement until I may have a chance to try it. This may work well in concert with the Intake-Exhaust Heat Shield from the prior page.
This ceramic insulation is made in Australia with distributors currently in Australia, New Zealand, and United Kingdom. For more information on the insulation, see ACL Race Series Performance Products