Just bought form a fellow hamber a complet 2x2 to 4 intake set up I was told it was bought form a repetable carb builder. I know who but I won't say The owner said he was selling it because he could not get it to run right. Ok so far. I bought this for my buddy Bob that has a modle A with a weard fire wall and cant run 3x2 as of yet. This thing is complete with air cleaners, linkage, chrome arcorn nuts all very cute. Knowing quit a little abought carbs and that I am jumping in to some ones problems here we go. We bolt it on the guy we bought it from was right runs like crap. Frist thing i find is secondery carb is pulling much air from butterflys we pull the carb apart to adj butterflys they were the stock steel thin ones. I install a shaft and thick aluminum buterflys i had laying around from speed way and adjust them. That problem solved. Now for the part i need some help. Motor is a 350 ci with a mild comp cam used to idle at 750 out of gear and no problem when put in gear. Know it dies when put in gear. I know the primary carb is to lean have checked for vacume leaks with propane no leaks. But when i cup my hand over carb motor speeds up. (lean). does anyone have experance with these adaptors do the carbs get a good vacume signal. Rear carb is the primary and sets toward the back of the intake like in the secondary area. Also the butterflys are uncovering to much o the off idle transfer slot. I know i can drill out the idle jets to richen the mixture. I have done this befor but never on a 2 jet only Q jet. On some hollys i have had to drill a 1/16 hole in the primarys to get the butterflys closed with a big cam. But i don't think that should be the case here. Any one got some xeperance with these 2X2 to 4 barrel adaptors. thanks jim
I would run one carb at a time.. Take one off and put a block off plate on and adjust that carb.. Then take that one off and put the other on and adjust it.. When they both run good as singles, put them both on and then start your final adjustments.. I'm sure there are other ideas........
I ran one on a simillar engine combo-2 2gc's,but they were matched tag carbs. Couldn't just step down and smoke tire,but never poped or wheezed at the get go.Stock jets,and just some rebuild kits were the ticket. Maybe I was lucky?
I think having matching tag carbs is the key. I've never messed with multiple carbs and just put 2 on a 283 with progressive linkage and a vintage speed y adapter. Works awesome, just messing with when the second carb kicks in. got the second carb on ebay and rebuilt them both.
I run 3X2 on my car and have learned much from this. The front carb whitch is the secondary carb with the new shaft and butterflys is not the problem it is leaking zero air. Only problem we are having is at idle as I said lean at idle put your hand over the top and choke it motor runs faster. Bob took carb of and took it apart now i need to put it back together to see how much of off idle transfer slot is expoised. Any one have a lean condition runing this set up. thanks jim
I have one on my 56 olds 324. The back one is vacumed and both are 94 holleys. Custom made linkage. Not to bad to set up.
sounds like the "carb builder" isnt any good at what he's supposed to be good at, not very repetable, woudnt you say? sounds like you have had to do way too much to a "good to go" set up for him to be concitered a reliable source for this type of thing. sucks to have to clean up after someone who is supposed to know WTF they are doing
Well that is pretty much the story of my life. I have learned to do a lot of things over the years because the "professionals" were not very adept at doing what they do. I can't even say it is a sign of the times, it has been common as long as I have been alive. What they say in KC is that if you are too drunk to hold down a job you go into business for yourself.
Or become a public servant...hahahah..not what really sucks is, no one called the "original builder" out, on the shit they sold crap like that needs to fly back thru the window
I've found that it is cheeper and quicker to just do it your self, trying to deal with the carb builder can be good but in most cases not worth the time and efort.
These sell in the 600.00 dollar range. The person I bought it from said there was promlems thats why we got it for 250.00. He was honest I dont have a problem with him or the original builder. Now the guy I bought it from would and should have a just complaint. Just seeing if anyone has experanced idle problems with this set up and how they cured it. Off idle transfer uncovered to much or just need to drill idle jets. KCCOS what intake are you running. thanks jim
I would do what scrap metal 48 suggested and do the process of elimination. Take one carb off, build a simple block off plate and see if the problem goes away, then try the other carb all by itself. I had the same setup from Vintage Speed on my 23 and had an annoying problem. If I got on the car a little hard it would not idle right after that. If I shut it off and restarted it the car would run fine. I finally found out the stop that pushes the front carb closed was not adjusted right and the front carb was hanging open just ever so much and if I pushed it closed it idled fine. After adjusting the stop so it would shove the front carb closed a tad sooner the problem was gone. If you got it for $ 250 you have a lot of room to fix the problem, they are in the $ 600-$700 range new. Don
Just a SWAG but have you measured the vacuum on this setup? Dying when stopping can be either lean or rich I'm thinking. So vacuum is the means by which you figure that out. I was told, and it works, is to take the carb you're working on and hook vacuum to it and take it in your front seat with you while driving or performing whatever function you're trying to figure out. (Put a similar carb on the motor just so you can watch the one you're working on -) All you really have there is a four barrel carb sawed in half. Primary runs the idle and transition and the secondary runs the rest -
Agree, thats what I have done, with the exception of a good source for parts in my locality, but for some guys that isnt an option , so they trust the "carb" guy to have it good when they hand over all that cash To the OP..$250 , you done good..too bad the original buyer couldnt get it to work..it sounds like you have already had to do, what should have been done before it left the shelf
If you have a secondary carburetor working off of a progressive linkage It may not have any idle circuits in them or they may be plugged. When you cup your hand over the secondary carb the main system may be feeding. If this is the case you need to richen the idle on the primary. If you are idleing off of both carbs ignore me.
Secondary has no idle or power valve it is a true dumper. There is no air running threw it at idle. I am sure no vacume with your hand cuped over venteri and dose not pick up when you add propane in side carb. Looks like i may have found problem. I drilled idle jets no help at all. Back apart again. Looks like some one has drilled the idle air bleeds a bumnch. Now back to the drawing board.
I got it new cluster fixed it. Do any of you guys run the accelerator pump rubber on the secondry carbs? I dont but this secondery carb dose any ideas. thanks jim
Mine just operated as were stock. If I remember correctelly- 250cfm? Non progressive,and it was all at one time. But if i'm correct,500 cfm isn't a deal breaker for a sbc. Like posted above^,seperate the carbs. But,if you have one that's just a "dumper",throw a kit at it,square it away to stock,and give it a whirl. Think of it this way- If you had a single 4,what would you run? A 600 cfm is about the smallest carb goin' these days. A kit for a 2GC is like $25,so give it a try. Your messing with the fuel curve,and probably richining the crap out of it at part throttle. Vacuum will be pulled off one carb. Just tryin' to solve some probs here..... I'll keep watching progress.
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