Flapper Boxes

It was pointed out to me by fellow 356 Registry list member Timothy Berardelli that the higher than normal oil temps may be linked to the lack of flapper boxes. He made the comment that they are very important to directing the cooling air and I'm thinking now that they may help in scavenging the exiting hot air out of the general vicinity of the engine. He also mentioned that the factory added the pieces to help balance the cooling betwen cylinders. Makes perfect sense to me. I am going to fabricate some aluminum plates to simulate the flapper boxes, as the stock ones don't fit with Skirmants race header.