2 replies to this topic

[Sidepipes V/C]

What is the small canister in the upper right of the photo with hoses coming out of either side?



Curious as to its function and how crucial it is.
Thanks

[Roger]

My scanner is on the fritz right now or I would post the picture from the parts book,,, but I'm 90% sure its called an "air bypass valve assembly". Or just air bypass valve. I can't tell ya what it does though. Just that its (obviously) part of the emissions stuff. Here's a link to a mustang site that has some info on each of the emissions parts in a similar setup.
http://mustangpartst.../Emissions.html

The only number I see listed for the van part is one for 1969. That number is C8TZ-9B289-A and says "before serial number 68,001". For 74, the first 4 digits (and maybe the last letter) of the part number might be slightly different.

[EmilBarnabas]

There is an air pump, which looks like an extra alternator, that feeds air into the part you mentioned via the top hose. From there the air goes through the bottom hose and into the horizontal metal pipe that sends the fresh air into the exhaust system to burn up any gas that did not get burned in the composition chamber. This method of combating pollution started showing up in 1968.

Back in 1968, only some of the engines had this system attached. The ones that did not had a plug screwed into the engine where your horizontal metal pipe attaches on both sides. I wonder if the pipe threads are in your block? If so. the plug looks something like this and can be found in the plumbing section of a hardware store.