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Hi All, My 72 has Just arrived in the UK from US and looking around the engine bay it seems there is no connection to the Vac advance unit on the distributor. There is a hose (marked E in photos) that attaches to the carb but the other end is hanging loose and appears it would not connect to the Vac advance as its a bit of an odd looking hose. Research I have done seems to indicate that port "D" should run to the vac advance but is currently capped off. Hose "C" runs to the valve cover breather. The engine and carb seem are not original and seem to date from different years but car has AC (now removed) auto transmittion and power brakes.
The link below shows the set up on a 1974.
Port A connects to transmission controlled spark solenoid which you dont have..
Test port A on a running engine to insure you have vacuum at idle and above idle. If you do connect it to the distributor.
C should run to the PCV not a breather.
D runs to a thermostatic valve which you dont need.
B is a little puzzling it seems to head towards the drivers side firewall but may not be needed in your case, it may have been used for cowl induction.
E may be for the vacuum modulator on the automatic transmission. Not sure why it has those additional pieces. https://www.corvetteforum.com/forums...am-please.html
The link below shows the set up on a 1974.
Port A connects to transmission controlled spark solenoid which you dont have..
Test port A on a running engine to insure you have vacuum at idle and above idle. If you do connect it to the distributor.
C should run to the PCV not a breather.
D runs to a thermostatic valve which you dont need.
B is a little puzzling it seems to head towards the drivers side firewall but may not be needed in your case, it may have been used for cowl induction.
E may be for the vacuum modulator on the automatic transmission. Not sure why it has those additional pieces. https://www.corvetteforum.com/forums...am-please.html
Thanks, very informative so much great info on here for me.. Not sure what you mean about port B though as it's capped off?
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
on my 68 I use E for vacuum advance on the dizzy. The hose E was disconnected and plugged by our friend Bubba. That looks like a ball point pen stuffed in there as a plug. Pull it out and see if it still writes, then hang it on the wall.
on my 68 I use E for vacuum advance on the dizzy. The hose E was disconnected and plugged by our friend Bubba. That looks like a ball point pen stuffed in there as a plug. Pull it out and see if it still writes, then hang it on the wall.
Well Rescue Rogers, who would have thought it, you are absolutely correct. It is indeed a ball point pen shoved in there. And there’s me thinking it was some kind of specialist cable with multiple cores.
Unfortunately the pen will need a full frame off restoration prior to being put back into service!
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Lol. Be careful while your rehabbing that pen, you might put more money into it than you can recoup
I'm currently a custodian at a middle school and I see a lot of different pen manufacturers. That I believe is a type 3a version of Pental manufacture popular in the 2015 to 2017 production years. It would have had black ink as denoted by the grip color ( I'm saying that in my Cliff Clavin voice from Cheers) lol
Hose E has to be one of the greatest Bubba inventions I have seen ever!
I think there is a post on here that has a Hall of Fame of Bubba Inventions and this picture should be added to it!
Quadrajet Vacuum connections
