Warped Exhaust Manifold

[fluegel]

I've got the manifolds off on my 260z to check for exhaust leaks as discussed in a previous topic  'clacking noise'. The problem appears to be caused by a warped exhaust manifold. I had the face linished years ago and it is still flat but I found that the front and rear exhaust ports are hardly covering the gasket at the bottom where there appears to be a leak. Checking with a straight edge the ports are not in a straight line and also the gasket does not fit exactly ie the front and rear ports are too high by about 3mm each. Obviously the manifold is warped so that the ends are higher the  the middle. Are there still straight ones out there or do I have to fit custom extractors, I would rather keep things original, a spare I have is also warped in the same way.

 

Richard

Edited April 16, 2016 by fluegel

[PeterH]

Hi Richard

 

I can't help you with a manifold but I had a look a spare one I have here....it is in the same way....does any one know if " warping " like that is a common problem or is it, at least in part, just poor matching from the factory?

 

Pete 

[dat2kman]

What brands are these?

And,

How thick s the flat flange?

[PeterH]

I'm talking about a standard cast iron manifold..