Duncans Metal Pages
Seal Major - manifold
Last updated: 13 Nov 2018


The manifold is a single casting for inlet and exhaust.  Depending on how the manifold is machined and mounted, it is possible to have the carburettor on the top or bottom of the manifold, and the exhaust exit from the front or rear of the engine.

Skim 12-Feb-2007: A quick skim on the mounting face to start off.  The casting will stand on this face for all subsequent operations.
Top skim Top skim being taken after all drilling and tapping operations.  One of these castings had been ruined by drilling the ports - the drill had wandered depending on the casting shape above.  This replacement casting had the port holes slot drilled to prevent a repeat of the problem.
Ports 23-Feb-2007: Setup for facing/drilling/tapping the exhaust hole.  It seemed a bit easier doing it this way instead of trying to stand the casting up vertically in the mini mill.

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Warning: These pages consist of images and descriptions of equipment which can reach high temperatures creating hazardous and potentially dangerous situations.  These pages should not be taken as a step by step guide on how to construct any items or carry out any particular procedure, nor should any references to safety contained herein be taken to guarantee safety in all situations.