Injector line routing

[DeWitt Harrison]

At 03:23 PM 12/4/00 -0500, Matthew Beaubien wrote:
 > What about the o-rings?  What is the purpose of the black ones?  Do they 
just pilot the injector further down in the head?

Oh, yeah. Forgot. They do help locate the injector tip but,
I believe, they also provide an air seal for the air "shrouding"
pressure. Higher pressure air from before the throttle body
is routed into an air passage in the head which feeds each
injector position. I don't have one in front of me to verify this,
but there must then be small air openings in the injector body
between the two o-rings to allow this air to be forced through
the injector. The purpose of the shrouding air jet is to further
atomize the spray of fuel as it exits the injector tip.

This is still metered air so the a/f mixture control has no problem
with this small amount of air that bypasses the throttle plate.

Cheers,

DeWitt