Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Sign in using an external account
Register Forgot Password?
Register Search Today's Posts Mark Forums Read FAQ Vendor Directory
Search
C3 Tech/Performance
V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette Sponsored by
VBP

Welcome to Corvetteforum.com!
Welcome to Corvetteforum.com.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Corvetteforum.com today!


Corvette Store
 
 
C7 Parts & Accessories
C6 Parts & Accessories
C5 Parts & Accessories
C4 Parts & Accessories
C3 Parts & Accessories
C2 Parts & Accessories
C1 Parts & Accessories
Wheels & Tires
Sponsored Ads
 
 
Vendor Directory
  
Reply
 
 
 
 
Thread Tools Search this Thread
Old 04-04-2006, 05:30 PM   #1
njcardave
CF Senior Member
 
njcardave's Avatar
 
Member Since: Apr 2006
Default Rochchester Quadrajet carb to manifold gasket

I want to know what type of carburetor gasket to use with the divided plenum Edelbrock performer intake manifold. Should I use a gasket that just sits on the outer edge of the carb mounting flange on the intake manifold and has no gasket on the edge that divides the plenum in half or whould it be better to use the factory gasket that has the four holes cut in it for the carb butterflies? The factory gasket would seal the space between the plenum divider and the bottom of the carb.
njcardave is offline   Reply With Quote
Old 04-04-2006, 06:04 PM   #2
SanDiegoPaul
CF Senior Member
Support Corvetteforum!
 
SanDiegoPaul's Avatar
 
Member Since: Sep 2002
Location: San Diego - Deep Within The State of CONFUSION!
Default

Quote:
Originally Posted by njcardave
I want to know what type of carburetor gasket to use with the divided plenum Edelbrock performer intake manifold. Should I use a gasket that just sits on the outer edge of the carb mounting flange on the intake manifold and has no gasket on the edge that divides the plenum in half or whould it be better to use the factory gasket that has the four holes cut in it for the carb butterflies? The factory gasket would seal the space between the plenum divider and the bottom of the carb.
Use the former. Don't worry about the plenum divider.
SanDiegoPaul is offline   Reply With Quote
Old 04-04-2006, 07:25 PM   #3
dgruenke
CF Senior Member
 
dgruenke's Avatar
 
Member Since: Apr 2002
Location: New Baden Illinois
Default



Don't use the one with the four holes in it. Use the one that has the big opening.
dgruenke is offline   Reply With Quote
Old 04-04-2006, 07:27 PM   #4
comp
CF Senior Member
 
comp's Avatar
 
Member Since: Sep 2003
Location: eville in
Default

comp is offline   Reply With Quote
Old 04-04-2006, 08:18 PM   #5
TJ76
CF Senior Member
 
Member Since: Nov 2004
Location: Appleton Wi.
Default

Depending on the carb. you could try both. Mine with a q-jet wouldn't run right without the divided 4-hole q-jet gasket. With the Demon it also wouldn't run right wothout a 4-hole gasket. Even the gasket that the Demon came with, and the instructions say not to use any other, didn't work. Called tech. and they suggested to try a 4-hole, and it took right off. The tech told me that some motors reverberate back and forth between the two sides of the manifold under the carb otherwise. Some like it, some don't. Good luck, good thing it's not very expensive to try both ways.
TJ
TJ76 is offline   Reply With Quote
Old 04-04-2006, 08:19 PM   #6
rrhodes4
CF Senior Member
 
rrhodes4's Avatar
 
Member Since: Sep 2005
Location: Collierville TN
Default

My suggestion is while you have the Q-Jet unbolted, buy a new holley carb.
rrhodes4 is offline   Reply With Quote
Old 04-04-2006, 10:02 PM   #7
Sweet L82
CF Senior Member
 
Sweet L82's Avatar
 
Member Since: Feb 2006
Location: Houston Texas
Default

I just installed an Edelbrock Performer and a JET Stage 1 Q-Jet. My Q-Jet came with a gasket that DID NOT have the 4 holes and it runs good. Now that I think about it the old Q-Jet had a gasket that did not have the 4 holes either. hmmm. Make sure you properly torque the carb to specs - all bolts evenly.
Sweet L82 is offline   Reply With Quote
Old 04-05-2006, 01:16 AM   #8
Sprzout
CF Senior Member
 
Sprzout's Avatar
 
Member Since: Sep 2005
Location: Santee CA
Send a message via Yahoo to Sprzout
Default

Quote:
Originally Posted by rrhodes4
My suggestion is while you have the Q-Jet unbolted, buy a new holley carb.
Don't let Lars hear you say that...

Besides, why should we replace our 750 CFM Rochester Q-Jets with a 600 or 650 CFM Holley? Finding a 750 CFM Holley is going to be twice as much as a good rebuild on our Rochesters.
Sprzout is offline   Reply With Quote
Old 04-05-2006, 10:36 AM   #9
rrhodes4
CF Senior Member
 
rrhodes4's Avatar
 
Member Since: Sep 2005
Location: Collierville TN
Default

Quote:
Originally Posted by Sprzout
Don't let Lars hear you say that...

Besides, why should we replace our 750 CFM Rochester Q-Jets with a 600 or 650 CFM Holley? Finding a 750 CFM Holley is going to be twice as much as a good rebuild on our Rochesters.
I know, I know!!! I do agree that a Q-jet in prime condition I wouldn't change. But there are a ton of horror stories about rebuilds on them. Mine needed to be rebuilt and I found that the best alternative to it was the Holley 0-80555S. $325.00 AND NO WORRIES. A stock or slightley modified 350 engine doesn't handle a 750 cfm very well. Also I never called the Q-jet by its other name. The respect is there.
rrhodes4 is offline   Reply With Quote
Old 04-05-2006, 11:40 AM   #10
sweethence
CF Senior Member
 
sweethence's Avatar
 
Member Since: Jan 2006
Location: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
Send a message via MSN to sweethence Send a message via Yahoo to sweethence Send a message via Skype™ to sweethence
Default

Quote:
Originally Posted by njcardave
I want to know what type of carburetor gasket to use with the divided plenum Edelbrock performer intake manifold. Should I use a gasket that just sits on the outer edge of the carb mounting flange on the intake manifold and has no gasket on the edge that divides the plenum in half or whould it be better to use the factory gasket that has the four holes cut in it for the carb butterflies? The factory gasket would seal the space between the plenum divider and the bottom of the carb.

you will need the 4 hole gasket if you intend to use the original heat sheild, which i reccomend , but may not be required

.02


tim
sweethence is offline   Reply With Quote
Old 04-05-2006, 02:16 PM   #11
Duke94
CF Senior Member
 
Duke94's Avatar
 
Member Since: Mar 2001
Location: Ann Arbor Michigan
Default

While we're talking about carb gaskets, Is there suppose to be more than just the 1/4" thick gasket between the carb and manifold?
Duke94 is offline   Reply With Quote
Old 04-05-2006, 02:23 PM   #12
sweethence
CF Senior Member
 
sweethence's Avatar
 
Member Since: Jan 2006
Location: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
Send a message via MSN to sweethence Send a message via Yahoo to sweethence Send a message via Skype™ to sweethence
Default

Quote:
Originally Posted by Duke94
While we're talking about carb gaskets, Is there suppose to be more than just the 1/4" thick gasket between the carb and manifold?
Yes depending on the year there is a metal plate withthe same shape as the 4 hole gasket, called the Q-jet heat sheild originally used for all 1968-69 Corvettes with Rochester Q-Jet. The shield is supposed to be installed between the carburetor base and the gasket (i.e. on TOP of the gasket).

The shield is EXTREMELY important if the car remains equipped with an un-plugged heat groove on the forward part of the manifold carb flange. If you look at the carb flange on the manifold you will note this groove. At each end of the groove will be holes that connect the groove with the manifold's heat cross-over passage. Check the holes to see if they have been previously plugged with pipe plugs or cup-type plugs. If they have not been plugged, I strongly recommend that you do so. The easiest way to do this is to obtain some 3/8" cup-type plugs (mini "freeze plugs") that you can purchase at auto supply stores. Simply drive the plugs into the holes with the cup side up. This eliminates the heat groove functionality and will preservce the life of your carburetor without causing any detrimental effect. The heat groove causes the transfer of so much heat to the carburetor, even with the stainless steel heat shield installed, that carb throttle bodies and float bowls are often warped. GM eliminated this feature after 1969.

tim
sweethence is offline   Reply With Quote
Old 04-05-2006, 02:23 PM
 
Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Reload this Page Rochchester Quadrajet carb to manifold gasket
 
 
 
Reply

Tags
carb, carburetor, corvette, gasket, groove, heat, intake, manifold, manifolkd, metal, offy, performer, pictures, quadrajet, rochester, shield, stainless, steel


Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
carb to intake manifold specs mattu C3 Tech/Performance 6 10-02-2011 08:41 PM
carb to manifold torque specs mattu C3 General 1 09-29-2011 11:31 AM
66 327/300 carb gaskets Technite73 C1 & C2 Corvettes 1 10-24-2010 09:39 PM
64 SHP Intake Question EPL C1 & C2 Corvettes 13 04-09-2004 03:06 PM
Questions: TB Bypass, Plenum porting and air temp sensor brock71 C4 Tech/Performance 9 02-10-2004 09:30 PM


All times are GMT -4. The time now is 03:13 PM.


Emails & Password Backup