Early Exhaust Manifolds

[type26owner]

Whatda know the conical appearing male/female flange turns out to be a spherical ball and socket joint afterall. The spherical radius is 1-3/16". The flange on the downpipe can be swivel around by up to ten degrees I'm guessing and the sealing surface contact will remain gas tight. There also is an orientation on the two piece cast iron clamp I just found. On the rim of one are tiny cast in letters spelling out 'top'. Made the female flange 1/8" wall thickness so it will not bend so easily out of shape this time. Had to enlarge the vee groove in the clamps by grinding away material at each end so contact was made all the way around. Used .010" wire as a feeler gauge to make sure there was not any gap on both side of the clamps when the joint was cinched up tight. Having the clamps not fit just right the last time allowed the thinner female flange tubing to bend out of shape and chuff I suspect. This is the third major effort trying to permanently fix the leaking and hopefully the last.

Used the female flange with some blueing to rub onto the manifold's male flange highlighting the high spots. With a stone I was able to remove the casting imperfections in about twenty minutes of work. That manifold is tool steel hard. A mill smooth file won't cut it at all. Finally have an interface about 3/8" wide where any fire gum applied won't be blown away instantly. Betting fire gum is not even required now the fit is that good. A coating of soot will seal the gap.

[type26owner]

Bingo! Has never been this muffled before. I'll have to get used to the new subdued toned down exhaust note. The bung for the vacuum check valve was a real pain to position into a place so the downpipe could be removed without any fuss or bother and still have room for the rubber hose to clear the oilpan. It's a just fit situation. Typical Lotus engineering. <_<