I'm wrapping some headers to try and hold the heat down in a mid-engine Corvair conversion. The instructions are confusing. One statement says to wrap the pipes only to the collector, which I'm assuming means to wrap them till the 4 pipes merge into one big pipe. Another statment says to wrap them all the way to the three bolt collector flange. Anybody have experience with this? How far do you wrap the headers? I've also heard the stories about how wrapping headers shortens the life of the header. Any comments on that? Experience?

67shovel,

We wrapped ours to the three bolts, but that was because we were trying to keep the heat down as much as possible. If you are just trying to keep the heat down in the engine area, wrap them to the collector. Wrapping them does shorten the life, as the headers will rust under the wrapping. As least when we took the wrapping off this past summer, the headers had a coating of rust in several areas. That's all the experience that I have on wrapping headers.

Fred.

Not only do you get corrosion, but the hot strength of the steel in the headers will become a consideration. If the headers have a lot of exhaust stuff hanging on them to weigh them down, you can expect cracks. The Corvair will probably have a pretty short and light system, so a full wrap would be OK. Dang, we got some Corvair topics this week. It's OK with me as I have owned 5 of them. And liked them.