My early 67 restoration project has a later model 1600 block
R-108896, with the air injection stubs capped off, etc. I noticed
a "hose to nowhere" on the top of the intake. Just inboard from each
carb on the top of the manifold is a pipe nipple with a piece of
heater hose connecting the two. I am planning on doing away with
this, as the two sides of the intake are interconnected
internally above the heat pipe. Figure on putting 2 pipe plugs in the
holes, just to clean up the appearance of the engine a little.
I think the PO just hooked them together as an expedient way to
cover the holes. But my question is: (1)What the heck were they
used for originally? A giant vacuum port? Maybe a vacuum
switch for the air injection or a pcv valve?
and (2) Am I right that replacing the nipples and hose with some
pipe plugs will have no effect on performance. These are heater
hose size nipples, so its not just some normal vacuum line, like to
the distributor vacuum advance. Reaching down the intake, each
nipple comes out into the intake just before the intake passage
splits into 2 sections. I was thinking EGR, but that wasnt used
as an air pollution control gizmo until about 1973 as I recall.
Thanks for any advice on this!
Jim
67 pushrod 2liter
SPL 311 09059
Chesapeake Va
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