Originally Posted by
warrenpenalver
Im surprised someone hasnt recast the MIS one in alloy. sure lots of people want an uprated manifold but upto £3k just doesnt seem good value
even if your spending £20k on engine work!
Magnesium has a different shrinkage rate when compared to aluminium, it would cost too much money to alter the pattern, adding to the cost of the MIS manifolds, the cost of either metal is not much different.
The originals were mag to keep the weight to a sensible level, although I understand that there were some cast in aluminium which had trouble with snapping the lower inlet part of the YB head even, with a vibration damper fitted.
The cost of MIS type manifolds is nearer £2k.
Steve