building a pr of WCFB 2x4 clones
10-04-2011, 03:37 AM
#1
Drifting
Thread Starter
building a pr of WCFB 2x4 clones
What do I need to make a pair of 1x4s look like a clone 2x4 set up. Do all of the primary carbs of a 2x4 have the choke up high (like the pre 57 1x4s)? It's for a 1960 Vette. Lots of pictures (from all side) would also be helpful. What else do I need to do to change what was a 1x4 to the secondary carb on a 2x4 set up. I know the secondary carb had no choke butterfly or any other of the choke parts. If someone has made a nice clone pair, it would be good to hear from you.
Ta
Mick
Ta
Mick
10-04-2011, 07:32 AM
#2
Team Owner
What do I need to make a pair of 1x4s look like a clone 2x4 set up. Do all of the primary carbs of a 2x4 have the choke up high (like the pre 57 1x4s)? It's for a 1960 Vette. Lots of pictures (from all side) would also be helpful. What else do I need to do to change what was a 1x4 to the secondary carb on a 2x4 set up. I know the secondary carb had no choke butterfly or any other of the choke parts. If someone has made a nice clone pair, it would be good to hear from you.
Ta
Mick
Ta
Mick
Then depending on whether or not you are cloning 245HP or 270HP carbs you have to select counterweights for the flappers and perhaps the counterweight arms according to the attached article. The internal changes will also depend on where you are going with the setup and the engine application.
FTF
Last edited by Frankie the Fink; 10-04-2011 at 07:36 AM.
10-04-2011, 08:14 AM
#3
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All of the above is good information.
One thing I would add, and this general question has come up before, is the added height of NON-2x4 carbs. The cast iron base plate of the 1x4 carbs is thicker than the base plate of 2x4 carbs. Also, there is a slight variation in the bolt pattern between the base plate/main body of 1x4 and 2x4 carbs. Thus, you CANNOT swap a 1x4 and 2x4 base plate.
MANY years ago, I ran a pair of 1x4 carbs on a Corvette manifold and there was no clearance issues under the hood of the 56---------------------BUT, a low profile air cleaner is a must! When I removed the choke and linkage from the front carb, I simply ran a long 5/16in bolt through the holes. The choke butterfly shaft is 5/16in, so the bolt by itself shouldn't affect flow.
There was once a time when 2x4 setups didn't have much value at all ($40-60), ESPECIALLY 2x4 setups that were pieced together from mismatched carbs. So when I got rid of mine (AFTER acquiring a matching carb setup), I think I sold if for $20. Today, properly rebuilt and recolored 2x4 setups bring premium prices. My matched set has been bagged up and on the shelf for about 30yrs since I replaced it with FI. And yes, I STILL plan to install it someday when I find the right car------------------and a Batwing to go with it! (I almost put them on the 383 that I just built for the 51)
BY THE WAY FRANK,
Those look incredibly great!
Tom Parsons
One thing I would add, and this general question has come up before, is the added height of NON-2x4 carbs. The cast iron base plate of the 1x4 carbs is thicker than the base plate of 2x4 carbs. Also, there is a slight variation in the bolt pattern between the base plate/main body of 1x4 and 2x4 carbs. Thus, you CANNOT swap a 1x4 and 2x4 base plate.
MANY years ago, I ran a pair of 1x4 carbs on a Corvette manifold and there was no clearance issues under the hood of the 56---------------------BUT, a low profile air cleaner is a must! When I removed the choke and linkage from the front carb, I simply ran a long 5/16in bolt through the holes. The choke butterfly shaft is 5/16in, so the bolt by itself shouldn't affect flow.
There was once a time when 2x4 setups didn't have much value at all ($40-60), ESPECIALLY 2x4 setups that were pieced together from mismatched carbs. So when I got rid of mine (AFTER acquiring a matching carb setup), I think I sold if for $20. Today, properly rebuilt and recolored 2x4 setups bring premium prices. My matched set has been bagged up and on the shelf for about 30yrs since I replaced it with FI. And yes, I STILL plan to install it someday when I find the right car------------------and a Batwing to go with it! (I almost put them on the 383 that I just built for the 51)
BY THE WAY FRANK,
Those look incredibly great!
Tom Parsons
Last edited by DZAUTO; 10-04-2011 at 08:17 AM.
10-04-2011, 08:21 AM
#4
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Oh yes, one other thing I failed to point out.
The 1x4 carbs, such as 57-later WCFBs have a greater CFM than the 2x4 WCFBs. So, the TOTAL CFM of matching 2x4 carbs is about 770cfm, while a pair of 1x4 carbs, such as on Franks engine will be over 800cfm total!! That's a plus for larger engines!
If I were going to build up a 2x4 setup from a pair of 1x4 carbs, I'd try to locate identical carbs from something such as a 57-58-59 4bl 283/PG pass car. And personally, I wouldn't change anything internally, and I'd retain the same arm/weight for the auxillary air valve on the secondary side. Those 1x4 carbs worked just fine on the earlier 283s.
Tom Parsons
The 1x4 carbs, such as 57-later WCFBs have a greater CFM than the 2x4 WCFBs. So, the TOTAL CFM of matching 2x4 carbs is about 770cfm, while a pair of 1x4 carbs, such as on Franks engine will be over 800cfm total!! That's a plus for larger engines!
If I were going to build up a 2x4 setup from a pair of 1x4 carbs, I'd try to locate identical carbs from something such as a 57-58-59 4bl 283/PG pass car. And personally, I wouldn't change anything internally, and I'd retain the same arm/weight for the auxillary air valve on the secondary side. Those 1x4 carbs worked just fine on the earlier 283s.
Tom Parsons
Last edited by DZAUTO; 10-04-2011 at 08:27 AM.
10-04-2011, 08:27 AM
#5
Burning Brakes
another difference between 1x4 and 2x4 carbs, single carbs have a 1" venturi , and the 2x4 carbs have 15/16" venturi,,,, i don't know how that affects tuning them, or rejetting,,,but i'm also interested in building a set of clones for my 56....
10-04-2011, 12:36 PM
#6
Team Owner
Thanks Tom - the darn clones on the car run so well I've delayed installing my 'real deal' 270hp dual quads just back from a fresh Bob Kunz restoration...if it ain't broke....
The Chrysler WCFBs also have larger bores; however true CFM is controlled by the rear flappers/counterweights and depend a lot on the characteristics of a particular engine. I don't think the thicker base is a big issue from a clearance standpoint....I put 1/4" spacers under my thin base carbs and the hood still clears just fine so a thicker base should present no problem.
The Chrysler WCFBs also have larger bores; however true CFM is controlled by the rear flappers/counterweights and depend a lot on the characteristics of a particular engine. I don't think the thicker base is a big issue from a clearance standpoint....I put 1/4" spacers under my thin base carbs and the hood still clears just fine so a thicker base should present no problem.
10-04-2011, 12:52 PM
#7
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Yep, you should be just fine.
Tom Parsons
Tom Parsons
10-05-2011, 07:28 AM
#8
Drifting
Thread Starter
Good information guys, its a shame I seem to have a shed load of 1x4s with the choke mechanism down low. I have seen that every now and then a reasonable high choke carbi sells for a reasonable price ............. I bought one of these the other day once I realised the 2x4s all had high chokes. Why did they only change the 1x4 to the new choke location and then leave the 2x4s with the earlier design?
It was also my intention as advised in an earlier thread to purchase a pr of those phenolic spacers and I'll do the plastecine/putty check to ensure there is clearance between the hood and top of the air filter.
FTF, those photos are real good and say a 1000 words with much clarity.
Are there specific carbi numbers I should be looking for such as 2669s (Main 0-1208 + Air 6-1354 + Throttle 1-1386), 26655s (0-1108 + 6-1271 + 1-1386) or 2366s (0-953 + 6-1098 + 1-1386)?
Also, I believe that the top cooling water fitting is different between a 1x4 and a 2x4manifold .......is this correct?
It was also my intention as advised in an earlier thread to purchase a pr of those phenolic spacers and I'll do the plastecine/putty check to ensure there is clearance between the hood and top of the air filter.
FTF, those photos are real good and say a 1000 words with much clarity.
Are there specific carbi numbers I should be looking for such as 2669s (Main 0-1208 + Air 6-1354 + Throttle 1-1386), 26655s (0-1108 + 6-1271 + 1-1386) or 2366s (0-953 + 6-1098 + 1-1386)?
Also, I believe that the top cooling water fitting is different between a 1x4 and a 2x4manifold .......is this correct?
10-05-2011, 07:34 AM
#9
Drifting
Thread Starter
FTF, I just had another careful look at the secondary carbi (without the choke) from the left and can't make out what is going on with the primary butterfly linkage it looks like there is no linkage and from the right side it is obscured by the fuel filter.
It almost looks like the high choke has something to do with clearances and a low choke would have interferred with the secondary carbi.
ALSO, what is the rubber hose that runs beteen the carbs as viewed from the right?
Thanks again
It almost looks like the high choke has something to do with clearances and a low choke would have interferred with the secondary carbi.
ALSO, what is the rubber hose that runs beteen the carbs as viewed from the right?
Thanks again
10-05-2011, 08:14 AM
#10
Team Owner
The rubber hose is my home made version of RPO-242 (an early PCV system for Corvettes). This positive crankcase ventilation method replaces the original "road draft" tube. The rubber hose goes to the PCV valve at the back of the front carb. You probably don't need (or want) to do that.
Look - these old carbs are not rocket science and I have run low and high chokes and even a single carb on a 2X4 manifold using a "block off" plate in front. I wouldn't over-analyze it and nearly any WCFB (regardless of numbers) can be made to work. The "low choke" carb in the picture is off a Buick and I never did anything to it except cobble it onto the manifold and adjust the idle while my 2X4s were being rebuilt.
If I were cloning this carb for permanent use the huge flapper counterweight would have to go though....it is clearly for an engine that pulls more vacuum that my solid lifter, Duntov cam-based car. Looking at the picture I don't see how the low choke would interfere with the front carb but I haven't tried putting a front carb on so can't swear to it.
Look - these old carbs are not rocket science and I have run low and high chokes and even a single carb on a 2X4 manifold using a "block off" plate in front. I wouldn't over-analyze it and nearly any WCFB (regardless of numbers) can be made to work. The "low choke" carb in the picture is off a Buick and I never did anything to it except cobble it onto the manifold and adjust the idle while my 2X4s were being rebuilt.
If I were cloning this carb for permanent use the huge flapper counterweight would have to go though....it is clearly for an engine that pulls more vacuum that my solid lifter, Duntov cam-based car. Looking at the picture I don't see how the low choke would interfere with the front carb but I haven't tried putting a front carb on so can't swear to it.
Last edited by Frankie the Fink; 10-05-2011 at 08:31 AM.
04-11-2012, 03:44 AM
#12
Drifting
Thread Starter
2x4s are ready but one more question, where do you hook up the vacuum advance for the distributor. I hear the original dual point type distributor had no vac advance. There are a number of holes in the side of the base plate of the primary carb ... can these be used to connect a vac advance line?
04-11-2012, 07:32 AM
#13
Team Owner
2x4s are ready but one more question, where do you hook up the vacuum advance for the distributor. I hear the original dual point type distributor had no vac advance. There are a number of holes in the side of the base plate of the primary carb ... can these be used to connect a vac advance line?
FYI - I run a billet Pertronix III distributor from Jegs with an adjustable vacuum advance can -- I think the whole deal cost me about $250 and the dual point (mechanical advance only) dizzy is in storage. Works great and haven't touched it since initial setup two years ago! If you want to reinstall the ignition shielding you may have to 'reclock' your distributor to fit under the shielding cuz of the vacuum advance can. No biggee.
Also FYI - original 1X4 WCFB setups had a hollow carb mounting stud that was used for vacuum advance (right hand, front stud in picture). Some go that route but I think it's ugly as all hell.
Pls post pics of your setup and tell all how it runs when you get time. Not many people have the courage to attempt this. Good on ya' mate...
Last edited by Frankie the Fink; 04-11-2012 at 07:50 AM.
04-12-2012, 06:22 PM
#14
Drifting
Thread Starter
FTF,
Now that I have your email (from carb manual request thread), I'll take some photos and send to you. Unfortunately, I'm a long way off a running vehicle so may be some time before I report back on how it all works/runs. I have just about completed the chassis/suspension/brakes/driveline restoration .... but have not even glanced at the body or interior resto .... apart from a lot of work is required. I'm extremely happy that I have weight on wheels ... even if the body is off.
Ta
Mick
Now that I have your email (from carb manual request thread), I'll take some photos and send to you. Unfortunately, I'm a long way off a running vehicle so may be some time before I report back on how it all works/runs. I have just about completed the chassis/suspension/brakes/driveline restoration .... but have not even glanced at the body or interior resto .... apart from a lot of work is required. I'm extremely happy that I have weight on wheels ... even if the body is off.
Ta
Mick
