Carb Insulator Needed?
Thread Starter
Burning Brakes
Joined: May 2002
Posts: 751
Likes: 8
From: Escondido CA
Carb Insulator Needed?
Hello, folks,
I am running an Edelbrock Performer 2101 manifold and a brand new Edelbrock 1406 carburetor on my otherwise stock 327-300. No spacers, just a single thin gasket between carb and manifold.
Cold startups are perfect and instantaneous, but I have a bit of difficulty starting up a warm engine (after sitting 5-10 minutes, has to crank over a few times before it will catch), thus I suspect a possible heat soak/percolation problem.
I know that this manifold & carb combination is fairly popular - has anyone else encountered this issue?
If so, can someone recommend an insulator/spacer setup that will clear the hood? I am using a 3" drop-down paper element air cleaner.
Thanks to all for your assistance!
I am running an Edelbrock Performer 2101 manifold and a brand new Edelbrock 1406 carburetor on my otherwise stock 327-300. No spacers, just a single thin gasket between carb and manifold.
Cold startups are perfect and instantaneous, but I have a bit of difficulty starting up a warm engine (after sitting 5-10 minutes, has to crank over a few times before it will catch), thus I suspect a possible heat soak/percolation problem.
I know that this manifold & carb combination is fairly popular - has anyone else encountered this issue?
If so, can someone recommend an insulator/spacer setup that will clear the hood? I am using a 3" drop-down paper element air cleaner.
Thanks to all for your assistance!
Safety Car
Joined: May 2005
Posts: 3,921
Likes: 46
From: So Cal
Strange-I'm having the same perc problem your having and my gas cap acts just like yours. I've put up with the perc problem for about a year and after my initial concern about pressure in the gas tank I disregarded the cap as defective. I've thought of putting on a parabolic or wood spacer- I have 1" of clearance- but now I think the whole issue is the gas cap. Any thoughts?
Pro
Joined: Sep 2008
Posts: 682
Likes: 0
From: Manteo NC
Have you tried insulating the fuel line better or switching to rubber gas line from pump to carb/lines? I use USCG approved marine fuel line and it's TOUGH.!! If it's a metal fuel line to the carb it may be "vapor locking". I had that issue on another car years ago. Same conclusion just different approach.
Your manifold is a spread bore correct? I had that at first and then switched to a Torquer 2 just recently when I rebuilt my 350 and went with a Holley 750 DP. I had to run a flat plate with the spread bore as I only had about 1/8-1/4 lip to seal carb to manifold with the square Holley.
Your manifold is a spread bore correct? I had that at first and then switched to a Torquer 2 just recently when I rebuilt my 350 and went with a Holley 750 DP. I had to run a flat plate with the spread bore as I only had about 1/8-1/4 lip to seal carb to manifold with the square Holley.
Last edited by obx2323; Jan 20, 2009 at 06:43 AM.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
I think you meant 'phenolic'. I put a 1/4" self-made phenolic spacer under my dual Carter WCFBs and it solved my heat soak problem (along with blocking off the heat riser passage in the intake manifold and wiring open the exhaust heat riser valve). My carb base runs at about 147 degrees now when measured with an I/R temp gun....way below perc levels.
Last edited by Frankie the Fink; Jan 20, 2009 at 06:46 AM.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
i like using the mr. gasket spacers that are a series of aluminum plates with gaskets sandwiched in between. you can adjust with as many as you want within reason. have to watch clearance for holleys on the pass. side for WOT..a simple filing does the trick jmho
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
Yeah really. I put some "dum dum" on top of my air cleaner studs and lightly closed the hood after adding the carb spacers and determined I have about 1/4" of clearance. Not much...but enough...
Drifting
Joined: Apr 2001
Posts: 1,401
Likes: 9
From: Holly Springs, Nort Cackalacky / Jupiter, Florida
I think you meant 'phenolic'. I put a 1/4" self-made phenolic spacer under my dual Carter WCFBs and it solved my heat soak problem (along with blocking off the heat riser passage in the intake manifold and wiring open the exhaust heat riser valve). My carb base runs at about 147 degrees now when measured with an I/R temp gun....way below perc levels.
RK
Instructor
Joined: Nov 2005
Posts: 160
Likes: 0
From: Hamden CT
The Edelbrock 1406 is a square-flange carburetor. GM used to make an insulator part #3969835, which I believe is discontinued. An equivalent thin insulator is available that will shield the carb from manifold heat, and provide an additional heat sink/gasket sandwich that is thin enough that it shouldn't affect your hood clearance.
Here are a couple of links for the shield:
National Parts Depot, section E, part #C-3726-100A. If the link shows as too small, click on the E section to enlarge it.
http://npd.dirxion.com/Main.asp
Doc Rebuild also has part #3726142 - scroll down toward the bottom of the page and click on the part # for item V.
http://www.docrebuild.com/dr-r-web/CARB-GASKET.HTML
Need to give credit here where credit is also due, as this thread came up in my search for the GM part # :
http://forums.corvetteforum.com/c3-g...carb-heat.html
Here are a couple of links for the shield:
National Parts Depot, section E, part #C-3726-100A. If the link shows as too small, click on the E section to enlarge it.
http://npd.dirxion.com/Main.asp
Doc Rebuild also has part #3726142 - scroll down toward the bottom of the page and click on the part # for item V.
http://www.docrebuild.com/dr-r-web/CARB-GASKET.HTML
Need to give credit here where credit is also due, as this thread came up in my search for the GM part # :
http://forums.corvetteforum.com/c3-g...carb-heat.html
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Team Owner
Joined: Aug 2007
Posts: 58,061
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Army
From McMaster: www.mcmaster.com
Here is the actual item number:
85315K164 Grade XX Garolite Sheet Black, 1/4" Thick, 24" X 24"
I bought a big piece so I could prototype a few designs (about $37)... I would think you could pretty much buy a Carter AFB, Holley or Edelbrock spacer at many places - non exist for the Carter WCFB carbs.
Here is the actual item number:
85315K164 Grade XX Garolite Sheet Black, 1/4" Thick, 24" X 24"
I bought a big piece so I could prototype a few designs (about $37)... I would think you could pretty much buy a Carter AFB, Holley or Edelbrock spacer at many places - non exist for the Carter WCFB carbs.
