rochester vacume port

Joined
Feb 9, 2002
Messages
1,186
Location
Utah
Visit site
ok ok, now i'm still going to try to get this rochester to work before i decide to back to the aisen.

i need to know where the vacume port is on my 2bbl rochester (i think the nipple has been pulled out and maybe a screw replace... but where?). if any of you have a manual and can look it up and scan a pic for me it would be great. i know there is a haynes manual on rochesters, but i'm sure there are other manuals too.

my carb ref# is 7012452

any help would be great. thanks alot
 

Gumby

Supamod
s-Moderator
Joined
Dec 13, 2002
Messages
12,310
Location
Knee deep in hookers and gin
Visit site
manifold vacuum is between the valves and the throttle valve of the carb. It reads high when the throttle is closed and low when the throttle is open. Ported vacuum is between the throttle plate and the top of the carb. It is high when the throttle is open and low at closed throttle.

I want to say there was two types of distributors. One used just ported and one used both.
 
Joined
Apr 26, 2003
Messages
279
Location
Mountains of WV
Visit site
Ive got a rochester on mine that has no vacuum ports either. I dont know if they ever did. These kits were originally sold by Man-a-fre, and they reccomended you install a non vacuum advance distributor by delco (I recently removed mine becuase it did not deliver proper advance). I put on a non-USA landcruiser distributor with a vacuum advance and ran the vacuum line to the manifold. Hey Gumby, what effect is there on the timing when the distributor line is connected to a manifold port verses one off the carb?
 

Gumby

Supamod
s-Moderator
Joined
Dec 13, 2002
Messages
12,310
Location
Knee deep in hookers and gin
Visit site
Most pull the advancing mechanism more advanced with the presance of vacuum. That would be the ported type. A manifold vac source to one of these would pull the advance full on at idle and let it retard as the throttle was opened.
The manifold source on some was to retard the timing under load to prevent spark knock, I beleive. I could be wrong on that one.
 
Joined
Feb 9, 2002
Messages
1,186
Location
Utah
Visit site
i don't see any port on my carb. there is however a screw that does absolutly nothing on the front left side (when standing in front of the bumper). i think i'm going to find me a nipple i can thread into this and see what happens.
 

Users who are viewing this thread

Top Bottom