On Sun, Feb 7, 2010 at 08:41, Frank Swygert <farna@xxxxxxx> wrote: Just the opposite -- sounds well within reason. I don't think I'd worry > about the furnace cement though. Since the insert will stay in place by > shape, don't worry about a little exhaust gas or heat rising into that well. > You main concern is flow, right? At anything above idle exhaust gas velocity > will be increased to a point that a small "crack" along the leading edges of > the insert won't matter. > > Actually I was more concerned with heat, eating the relatively thin (3/16") steel roof filler plate. I figured with hot gases on only one side the metal wouldn't cook. Cast iron has poor heat transfer and is much larger mass and has a water jacket under it. My steel roof will be thn and right in the exhaust. I also figured if it warped from heat then it could lift up and get hotter/warped-er... because I'd like this to be a one-shot deal and not do some long term development I prefer gross overkill. But I might just weld the three pieces in-place and be done. Tabs welded to the plug and a ver small milled notch on the head would let the manifold retain it and only reduce the gasket area 1/8" on two small spots. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://list.amc-list.com/pipermail/amc-list-amc-list.com/attachments/20100207/97ceb192/attachment.htm> _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com