CaliforniaSpecial.com -- Message Boards -- 1968 California Special Limited Edition Ford Mustang GT/CS
D I S C U S S I O N . F O R U M
COMMUNITY
1968 GT/CS & HCS
2007+ GT/CS
1966-1967 HCS

Vote!

Old 04/30/2007, 05:49 PM   #1
hcsstang
 

Location: Gettysburg, Pa.
Joined: Aug 02
eBay: hcsstang
Posts: 707

vacuum advance

I was at a local MCA show last Sun. and I was told that I should have the dual instead of a single advance. In the elbow I have a plug. What decides on which one that I should have . Every thing works with the single and I have no other holes for the vacuum lines. My car is a 302, automatic. Some one said that if you had smog devices the dual is used.

302 V4 HCS
hcsstang is offline   Reply With Quote
Old 05/01/2007, 01:32 AM   #2
GTCSMustang
 
GTCSMustang's Avatar
 

Location: Ridgecrest, Ca
Joined: Mar 03
Posts: 703

You were told wrong. It should be single advance for Mustangs with 302, 4-bbl, and automatic transmission.

Scott

68.5 Blck Mustang CJ Cnvrt, 68 Lme Gld GT/CS, 68 Rd HCS (fact 428), 68 Ac Bl Mustang GT Cnvrt, 68 Ylw GT500KR Cnvrt, 68 Hlnd Grn GT500KR Cnvrt, 68 Gld G.T. 500 Cnvrt, 68 Ryl Maroon Mustang Sprint Cpe, 68.5 Hlnd Grn Fstbck, 68.5 Ylw Mustang Fstbck. Visit my website www.scottfullerreproductions.com .
GTCSMustang is offline   Reply With Quote
Old 05/01/2007, 05:05 AM   #3
rvrtrash
 
rvrtrash's Avatar
 
So many cars, so little time!

Location: Post Falls, Id.
Joined: Apr 03
Posts: 3,443

My Garage
The plug in the thermostat housing is for a temp. switch that routes the vac. to your distributor. When water temp. increases, the switch changes the vac. source from your carb to the intake so the engine rpm will increase, driving the fan/water pump faster to help cool it off.

Steve

The wannabe formerly known as an owner.
rvrtrash is offline   Reply With Quote
Old 05/01/2007, 06:48 PM   #4
robert campbell
My Car Details
 

Location: Bremerton Washington
Joined: Apr 07
Posts: 3,654

My Garage
All
To my knowledge a Mustang built for California in 1968 should have the dual diaphragm distributor. This was part of the smog “stuff.” As Steve said it is in conjunction with a temperature activated switch in the thermo housing. The temperature switch worked with the distributor to alter advance curves at idle (vacuum) to curb emissions while at idle, in stop and go traffic as he engine came to op temperature. I like to call the distributor a “push me” “pull m” distributor when it has the dual diaphragm. Cars sold to DSO 72 should have them and cars sold outside of that DSO might not. In DSO 74 Seattle, this was not common. Denver cars were a special tune all of their own due to the altitude. I would doubt that your car should have a dual diaphragm.

Rob
robert campbell is offline   Reply With Quote
Old 05/01/2007, 08:34 PM   #5
GTCSMustang
 
GTCSMustang's Avatar
 

Location: Ridgecrest, Ca
Joined: Mar 03
Posts: 703

The only small-block V-8 Mustang produced in 1968 without a dual-diaphram vacuum advance is a 302 4-bbl with automatic transmission. All other engine configurations had the dual-diaphram vacuum advance. California delivered 302 4-bbl Mustangs with automatic transmissions also had the single-diaphram vacuum advance. There should be one green striped hose coming from the vacuum advance to the center port on the thermal vacuum switch.

68.5 Blck Mustang CJ Cnvrt, 68 Lme Gld GT/CS, 68 Rd HCS (fact 428), 68 Ac Bl Mustang GT Cnvrt, 68 Ylw GT500KR Cnvrt, 68 Hlnd Grn GT500KR Cnvrt, 68 Gld G.T. 500 Cnvrt, 68 Ryl Maroon Mustang Sprint Cpe, 68.5 Hlnd Grn Fstbck, 68.5 Ylw Mustang Fstbck. Visit my website www.scottfullerreproductions.com .
GTCSMustang is offline   Reply With Quote
Reply

  CaliforniaSpecial.com Forums > GT/CS and HCS Forums > GT/CS and HCS Discussions

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tuning issue on the CS 347 miller511 GT/CS and HCS Discussions 20 04/20/2007 04:13 PM
Pertronix and Vacuum Mosesatm GT/CS and HCS Discussions 10 10/14/2006 05:32 AM
Vacuum Issues & Diagram Needed 68Fan GT/CS and HCS Discussions 3 03/09/2006 10:58 PM
A/C Vacuum Can Issues darb GT/CS and HCS Discussions 2 04/26/2004 06:54 PM
A/C Vacuum Schematics darb GT/CS and HCS Discussions 5 06/23/2003 01:28 PM


All times are GMT -7. The time now is 04:23 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2017, vBulletin Solutions Inc.


This site created, owned and maintained by Jon Hanna - Copyright © 1996-2011
All rights reserved. CaliforniaSpecial.com is not affiliated with Ford Motor Company

ShowCase vBulletin Plugins by Drive Thru Online, Inc.