Fixed Orifice Tubes vs. VOV
Thread Starter
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Fixed Orifice Tubes vs. VOV
The parts book shows only one orifice tube for all years of C4s, 3033879, AC Delco 15-5151. I have heard that orifice tubes with smaller holes will work better at idle. Some research showed this:
Ford fixed orifice tubes:
Blue .067"
Red .062"
Orange .057"
Green .052"
Brown .047"
GM fixed orifice tubes:
White .072"
Black/White .072"
I also found this information on VOV (Variable Orifice Valves):
http://www.acsource.com/onsalesmartv...atormount.aspx
I have seen several recommendations to change to the Ford blue orifice tube to get better AC performance at idle. The VOV seems like the ideal fix. Does anybody have any experience with the VOV?
Ford fixed orifice tubes:
Blue .067"
Red .062"
Orange .057"
Green .052"
Brown .047"
GM fixed orifice tubes:
White .072"
Black/White .072"
I also found this information on VOV (Variable Orifice Valves):
http://www.acsource.com/onsalesmartv...atormount.aspx
I have seen several recommendations to change to the Ford blue orifice tube to get better AC performance at idle. The VOV seems like the ideal fix. Does anybody have any experience with the VOV?
Last edited by Cliff Harris; Aug 26, 2014 at 09:38 PM. Reason: Corrected spelling error.
Instructor
Joined: Jun 2014
Posts: 178
Likes: 3
From: Pensacola FL
The parts book shows only one orifice tube for all years of C4s, 3033879, AC Delco 15-5151. I have heard that orifice tubes with smaller holes will work better at idle. Some research showed this:
Ford fixed orifice tubes:
Blue .067"
Red .062"
Orange .057"
Green .052"
Brown .047"
GM fixed orifice tubes:
White .072"
Black/White .072"
I also found this information of VOV (Variable Orifice Valves):
http://www.acsource.com/onsalesmartv...atormount.aspx
I have seen several recommendations to change to the Ford blue orifice tube to get better AC performance at idle. The VOV seems like the ideal fix. Does anybody have any experience with the VOV?
Ford fixed orifice tubes:
Blue .067"
Red .062"
Orange .057"
Green .052"
Brown .047"
GM fixed orifice tubes:
White .072"
Black/White .072"
I also found this information of VOV (Variable Orifice Valves):
http://www.acsource.com/onsalesmartv...atormount.aspx
I have seen several recommendations to change to the Ford blue orifice tube to get better AC performance at idle. The VOV seems like the ideal fix. Does anybody have any experience with the VOV?
