Great Site!

I have an ECG 9424D dual quad intake manifold (57 Ford model) and would like to put 2 Edelbrock 500 cfm Performer series carbs on it. Specifically the model 1403.

I am going to install the Vintage Speed adapter plates #Fl-CA-8.

Has anyone successfully installed and ran these carbs? If so, what rods/jets, secondary springs & linkage was used?

Current car specs:

1956 Ford Victoria 2 door hardtop

312 bored .030 over with G heads

MSD Distributor

Isky E-4 Cam:

E-4 SOLID Low/Mid-Range performance cam

.425 EXT Valve Lift

.425 INT Valve Lift

Duration 260

Rockers - 1.54

Trans = Ford 4 speed toploader - close ratio

Rear End- 3.78

Any lessons learned would be appreciated.

Bruce



1956 Ford Victoria Hardtop



Fort Worth, TX

Bruce.  Unless someone inputs some specific experience with these carbs on your combination in regards to jetting, then leave the jetting stock for a baseline.  I didn’t think the 500 cfm Edelbrocks had secondary springs but instead have weighed air valves above the secondary venturies.  If they are weighted, then some mass will need to be removed from the air valve counterweights to compensate for the air flow to each carb being cut in half.  Depending upon which linkage setup you go with, the power valve springs will also need to be reduced in tension for the same air flow reduction reasons.  If the spring rates are not adjusted, you’ll likely have a lean condition in the mid rpm range.  You’ll obviously need two power valve spring kits to insure you’re putting the same springs in both carbs.  FYI.  There are two power valve springs in each carb.

 

In regards to linkage, there are two schools of thought.  First school says to run off of one carb for normal driving with that carb being the one whose primaries are closest to the center of the engine.  And to complicate this scenario even further is whether both carbs are responsible for idle adjustment or if just the primary carb has the majority of idle opening while the secondary carb has its idle blades closed off or just barely cracked open.  In this particular instance my own preference is to have the primary carb responsible for most of the idle with all idle adjustments being made off of this carb while the secondary carb has its idle open just enough to insure some idle mixture flow.  This will allow the secondary carb to have fresh fuel in it even if not being used regularly.  If the carbs are positioned backwards, you’ll be using the front carb as the primary carb and likewise, if the carbs are facing forward, then you’ll be using the rear carb as primary.  Rearward facing carbs would require a crossover bellcrank to get the linkage to the passenger side of the engine.  Regardless of how the carbs are positioned, the linkage would need a ‘slider’ on the secondary carb so it can stay in the closed or unused position until half to two thirds of the primary carb throttle opening is reached.  That means the pivot point for the secondary carb would have to be closer to the throttle shaft center point to insure that both carbs reach full throttle simultaneously.

 

The other school of thought has both carbs working as a pair and in unison.  You’ll likely have to slightly downsize the accelerator pump shooters in this instance or reposition the pump linkage in the other available holes for less shot volume to keep from being overly rich with the initial throttle opening.  Power valve spring adjustments (less tension) are a must in this scenario.  When initially adjusting the carbs, both carbs would be completely closed and then both carbs adjusted open the same amount on the idle speed screws whenever making any idle adjustments.  You’ll find that the idle mixture adjustment screws will also have to be screwed in significantly more versus that of a single carb setup.  Fuel mixture requirements is basically cut in half with both carbs sharing idle responsibility and will likely dictate ½ to ¾ turn max opening on each screw.

 

You didn’t mention where the camshaft was installed and this will also affect overall tuning.  Four to six degrees of cam advance will make for a stronger carb signal while the camshaft being installed straight up would likely require more idle mixture while also needing a richer overall mixture to overcome a reduced vacuum signal.  Still, the stock jets will provide a good baseline.

 

Hope this all helps.

Lorena, Texas (South of Waco)

Ted,

My engine is apart again. Do you suggest a 4-6 degree cam advance while I'm at it? I'm still running the Mummert cam at 270º 224º .440" 108º, When last installed it dialed in at 108º.

I think you've seen my 312 piston thread. I'm planning a bore to stock 312, deck at 0º. Balance and either G or 113 heads.

Never did figure out the vacuum secondary deal. Also when reading up on blow through carbs it seems there are a lost of baseline modifications to be made. I still don't quite understand why the 650 double pumper cant be made to work. I'd hate to buy a 570 and find the same problems! Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Chuck.  The 108° lobe centers on your cam is still somewhat short for a blower application and my own preference would be a camshaft ground with 112°-114° centers to minimize "blowthrough" during the overlap cycle.  Because your current camshaft is already ground on 108° lobe centers, then installing it straight up in your particular case would be desirable as this will minimize the effect of the intake valve closing too early.  As it is, the intake valve is already closing another 4° earlier with this camshaft as opposed to a camshaft ground on 112° which is increasing the dynamic compression ratio.  Loosening the valve lash can help to minimize the 'blowthru' effect in your particular instance but then compounds the dynamic compression ratio by raising it.

I trust that didn't get too deep.  I get that way early in the morning.  Maybe Hoosier can chime in and give some more input on your camshaft.

Lorena, Texas (South of Waco)

Chuck,

           If you already have the 650, you can probably sell or trade for a vacuum 600 for free. I'd go ahead and use the 650 though. Why won't it work? Re cams, what Ted said. If you contact Mummert and tell him what you want you'll be better off than using this cam. Same deal with the cam, sell it or put it up until you build a dual quad motor for the roadster. Along with what Ted said, and John will chime in here, you will want more lobe on the exhaust side in a Y. The exhaust ports need all the help they can get, especially with a blower.

                                                  Frank

g

Frank/Rebop

Bristol, In ( by Elkhart) 

Actually I have the 650 AND a vacuum 600. I need to solve the vacuum secondary issue to run the 600.

The cam was bought from Mummert for this application. I will contact him about a better one. Do you guys have a specific recommendation? Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Chuck,

      Tell me what the combination is you plan on, then we'll talk to Ted, John (both) and then you can get Engle to grind exactly what you want, or Mummert could get Crower to do it. Either way I think they have new cores and various profiles to choose from. In a blower car, for the street, you don't need a whole lot of duration. My cam is a factory replica, and it pulls HARD to 6500 with a TEAPOT!

 Feistritzer and Ted have forgotten more about cams than I'll ever learn, so you need to involve them, might as well use the resources!

                                                  

Frank/Rebop

Bristol, In ( by Elkhart) 

When I bought the cam from John he told me it was a little hotter than the factory F code cam. I didn't want to modify the heads if avoidable.

My next setup is to be a 292 bored to stock 312, Balanced, zero decked and running either the G or 113 heads. I have the Blue Thunder intake and car run either the 650 double pumper or the 600 vacuum secondary. Current fuel system is a boost referenced Holly HiPo 427 mechanical pump. Provides about 6lbs at Idle and revs to 10lbs. I have an Aeromotive electric pump but it looks like it will have to be trunk mounted due to the car being lowered. I would rather have it outside the car but the room around the rearend is at a premium. Ignition is a Mallory electronic unit with centrifical advance only. 1:54 ratio rockers and I do have heavier valve springs and aluminum keepers. Trans is still a tight FOM with a AOD in the works. Rear ratio is 3:80 posi but I also have a 4:10 unit. I have two sets of pulleys for the McCullouch a 4" that gets about 8-10lbs of boost and a 5" for street use. I'm also thinking of installing a blow off valve but don't really know if I need one?

I want to keep it streetable but fairly hot. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Another detour, When is Blue Thunder coming out with a dual quad manifold??? I haven't bought their single quad "Yet" because I am waiting for their dual.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Thanks for the inputs. I have included information from Edelbrock for those that are interested in using Edelbrock carbs on a Y block dual quad setup.

Concept is to use the back carburetor as the primary and the front as the secondary and operate them in a progressive mode. (note: both carbs facing forward with adapter plates)

Bruce



1956 Ford Victoria Hardtop



Fort Worth, TX