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-   -   edelbrock dual quads (https://www.corvetteforum.com/forums/c1-and-c2-corvettes/1805569-edelbrock-dual-quads.html)

63two 09-06-2007 06:51 AM

edelbrock dual quads
 
Looking for some advice this morning .I'm planing to relive my child hood and run a dual quad set -up on my 63. I know that that the motor will not run any better with the quads but I want the look. I have a vintage edelbrock c-26 and two new school 1406 afb's. My question what do I need for carb jets, where do i start, do I need to go a step or two rich or lean . the motor is a stock 300 hp with a 350 hp cam Thanks Steve

71zman 09-06-2007 11:26 AM

63two
I have the Edelbrock dual quad set-up on my 1960 and love it - when the second carb comes on - it feels like a nitrous kick:thumbs:

I have a 350 CI - ZZ4 crate motor in my car and bought the whole carb set-up from Summit. I went with two 1403 - 500 cfm - manual choke carbs leaving the stock jet set-up on them (Primary .086, Sec .095, Rods .065 X .052, orange step up spring). The car runs great with this set-up - no issues

I recommend the Edelbrock progressive linkage - a fine piece of engineering.

The only problems I have had was with the chokes. I went with the manual carbs as suggested by the tech support line at Edelbrock (because with two carbs - both idle circuits are on equalling a single carb with a choke.) I forgot to wire the chokes closed and had trouble idling - once I figured this out and wired them shut - no more problems.

The best news is that I can get 18mpg on the freeway running on the back carb :thumbs: - gas mileage and tire spin is a bit worse on the streets...... but sure is more fun:rofl: :rofl:

Plasticman 09-06-2007 11:57 AM

I also have a dual carb setup on my NOM 350 with an old Offenhauser manifold and two 500 cfm Carter AFBs. These carbs are the competition model, and do not have chokes. Frankly, the engine runs so well (even when I was back in Chicago in cold weather), that I never needed chokes. May stumble a tad for the first block, but then all is great.

Performance is great, and milage is "OK" at around 14, but that is more a function of cam, heads, driving style, etc. I averaged 14 with a 4.11 rear gear / Muncie, 14 with a 3.55 rear / Muncie, and now 14 with the 3.55 and OD trans. Just stuck @ 14 mpg no matter what! But is a lot nicer cruising (quieter) with the OD trans.

I also am running idle mixture off both front and rear carbs (front secondary carb throttle idle speed just closed, rear primary carb sets idle speed - both adjust idle mixture). This has been very stable once set (not like some Holleys I knew). Use a vac. gauge to set the idle mix (trying for maximum stable idle vacumm at the proper idle speed).

Note that I did have to put 5/16" thick insulator carb. to intake manifold gaskets (Edelbrock), plus blocked off the intake manifold crossover passage (also added a lifter valley shield - Moroso), and am running a 160 F thermostat. All due to carb. fuel boil over. Carter/Edelbrock AFBs have small fuel bowls that heat up rather easily to cause fuel boil over (come to a stop, and the engine will die or stumble a lot).

As for jets/rods, best to try them, and then adjust as required.

71ZMAN,

Hope you meant to say you wired the chokes "open"!

Plasticman

Black_Magic 09-06-2007 12:04 PM

I've got same setup as 71zman sitting on my workbench waiting to go in with new engine this fall/winter :) :)


http://www.stl-vettes.com/65vette/re...2/dsc06420.jpg

glenn64vette 09-06-2007 12:08 PM


Originally Posted by Plasticman (Post 1561805638)
I also have a dual carb setup on my NOM 350 with an old Offenhauser manifold and two 500 cfm Carter AFBs. These carbs are the competition model, and do not have chokes. Frankly, the engine runs so well (even when I was back in Chicago in cold weather), that I never needed chokes. May stumble a tad for the first block, but then all is great.

Performance is great, and milage is "OK" at around 14, but that is more a function of cam, heads, driving style, etc. I averaged 14 with a 4.11 rear gear / Muncie, 14 with a 3.55 rear / Muncie, and now 14 with the 3.55 and OD trans. Just stuck @ 14 mpg no matter what! But is a lot nicer cruising (quieter) with the OD trans.

I also am running idle mixture off both front and rear carbs (front secondary carb throttle idle speed just closed, rear primary carb sets idle speed - both adjust idle mixture). This has been very stable once set (not like some Holleys I knew). Use a vac. gauge to set the idle mix (trying for maximum stable idle vacumm at the proper idle speed).

Note that I did have to put 5/16" thick insulator carb. to intake manifold gaskets (Edelbrock), plus blocked off the intake manifold crossover passage (also added a lifter valley shield - Moroso), and am running a 160 F thermostat. All due to carb. fuel boil over. Carter/Edelbrock AFBs have small fuel bowls that heat up rather easily to cause fuel boil over (come to a stop, and the engine will die or stumble a lot).

As for jets/rods, best to try them, and then adjust as required.

71ZMAN,

Hope you meant to say you wired the chokes "open"!

Plasticman

Very simular to my early set up. Last year I went to the OFFY Hi-rise dual quad (new 500 performers). BIG improvement. :cheers:

dmentzer 09-06-2007 03:49 PM


Originally Posted by 63two (Post 1561802634)
Looking for some advice this morning .I'm planing to relive my child hood and run a dual quad set -up on my 63. I know that that the motor will not run any better with the quads but I want the look. I have a vintage edelbrock c-26 and two new school 1406 afb's. My question what do I need for carb jets, where do i start, do I need to go a step or two rich or lean . the motor is a stock 300 hp with a 350 hp cam Thanks Steve


I was thinking of using the Edelbrock dual quad setup on my 66 327/350. I contacted Edelbrock concerning the hood clearance with a small block hood. They cautioned me that it probably won't fit. Let us know if you do it and how much hood clearance you have. I still wouldn't mind trying it.

mjmsc5 09-06-2007 04:30 PM

The Edelbrock setup fits under the small block hood of my 65.
http://temp.corvetteforum.net/c5/mjmsc5//img_0736.jpg

dmentzer 09-06-2007 05:57 PM

Thanks mjmsc5. Looks like it has to be pretty close.

71zman 09-06-2007 06:51 PM


Originally Posted by Plasticman (Post 1561805638)
I also have a dual carb setup on my NOM 350 with an old Offenhauser manifold and two 500 cfm Carter AFBs. These carbs are the competition model, and do not have chokes. Frankly, the engine runs so well (even when I was back in Chicago in cold weather), that I never needed chokes. May stumble a tad for the first block, but then all is great.

Performance is great, and milage is "OK" at around 14, but that is more a function of cam, heads, driving style, etc. I averaged 14 with a 4.11 rear gear / Muncie, 14 with a 3.55 rear / Muncie, and now 14 with the 3.55 and OD trans. Just stuck @ 14 mpg no matter what! But is a lot nicer cruising (quieter) with the OD trans.

I also am running idle mixture off both front and rear carbs (front secondary carb throttle idle speed just closed, rear primary carb sets idle speed - both adjust idle mixture). This has been very stable once set (not like some Holleys I knew). Use a vac. gauge to set the idle mix (trying for maximum stable idle vacumm at the proper idle speed).

Note that I did have to put 5/16" thick insulator carb. to intake manifold gaskets (Edelbrock), plus blocked off the intake manifold crossover passage (also added a lifter valley shield - Moroso), and am running a 160 F thermostat. All due to carb. fuel boil over. Carter/Edelbrock AFBs have small fuel bowls that heat up rather easily to cause fuel boil over (come to a stop, and the engine will die or stumble a lot).

As for jets/rods, best to try them, and then adjust as required.

71ZMAN,

Hope you meant to say you wired the chokes "open"!

Plasticman

Yep - it seems to run better with the the chokes wired "open" - (in the space biz we would say that my processor experienced a SEU e. g. brain fart):crazy:


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