Jim asks:
> 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.
Those two ports hooked into the 'burp valve' from the air injector
pump. When you took your foot off the throttle, a vacuum valve (controlled
from the little vacuum-line-sized barb coming off the middle of the intake
manifold) opened and routed the output from the pump into these
ports. Forced the mixture to go lean and reduce backfires from the
otherwise-rich mixture exploding when it went into the exhaust
manifold and got that extra blast of air from the injector nozzles.
A couple of 1/4 inch pipe plugs will clean things up.
-- John
John F Sandhoff sandhoff@csus.edu Sacramento, CA
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