Dual Carb setup?

Has anyone ever used a dual four intake with a good carb and a blocked
off trash carb of the same kind so only one four is feeding the motor? The
other carb is for looks only! Dumb I know, but I have to ask with gas going
up all over the place.

KJ

 

I'd say try it,... It won't harm anything, and I'd guess it's been done.

4TTRUK

 

Thanks, 40FordGuy!
I have a like new dual carb intake for the engine that I hate to see go to waste!
KJ

 

Depends a whole lot on the manifold, some really won't feed but 4 cylinders well. And really if you tune it right and keep your foot out of it there won't be a whole lot of difference between 1 or 2 carbs.

 

Some of the old dual quad factory setups used the primaries of the second carb for idling/low speed driving with the front carb coming in with a progressive linkage followed by the secondaries of both carbs. With that I could see using the primary side of the secondary carb by itself if maximum milage was the goal. Essentially you'd have a 2 bbl carb for all of your driving.

Frank

 

If you study dual quad factory setups, you can see that the front barrels of the primary carb (the one with the choke) is located closest to the center of the engine. It was usually the rear carb that the ran the engine at low speeds except for the FE Fords where the Holleys were turned around backwards.

 

The type of intake is an important part of the equation here. Some 2x4s don's share a common plenum, that being the case one carb cannot be blocked off and progressive linkage will not work either.

If it is an intake that shares a common plenum I would not completely block off the secondary carb, I would just disable the secondary bbls of the secondary carb if I blocked anything at all off. Unless we are talking about a tunnel ram with a large open plenum. Then I may just run on the back carb as long as it was big enough to keep the plenum full of air.

So what kind of nice intake are we talking about here?

 

I really like big*****s.
I can't afford a***** job.
Can I just put toilet paper in the bra so it looks like big*****s.

Ooops wrong forum. But its the same*****.

Keep your foot out of it, set it up progressive and do this***** right.

 

X2, that's inline with what I was thinking

Exactly

 

It may wind up looking cool to do it, but I would think that you'd have worse performance running a 2 carb manifold compared to just running a dual plane or whatever type single carb manifold.

I'm sure everyone on here understands you wanting your ride to look cool, but, it just seems like a waste to sacrifice performance just to pose.

 

funny stuff right there

 

Another concern would be the engine, what size? I had a bbc with dual quads and ran the linkage 1:1. If not, the front cylinders ran hot. When my buddy saw my set-up, he asked why? He reset his linkage to run 1:1, on his 427 and his temp dropped 15 degrees. Small blocks don't seem to have that problem.

 

What type intake and cam? what was the vac?. Weak vacuum signal will do that also.

 

Johnny
I have an older offy here. I can see where G.G is comming from, the plenum is fine @ the carbs but the cross over between the carbs is real small, even with the manifold full of mix the fronts will want to starve.

That is one for the reasons for leaving the idle circuit intact, on both carbs. If you are running on your rear carb alone with my particular setup your fronts would want to run lean until you start pulling some fuel from the front carb.

 

Yes, all valid point's PB. That's why I aked what intake. Like any engine set up, what work's with one combo won't work in other's. Then it becomes like picking fly***** out of the pepper .

 

Is the dual carb setup going on yer daily driver....or work car?
If not....run 'em both...there's more to hotrodding than MPG.....

Did I hear*****ies??? hehe

 

How about 2 2barrels on adapter plates?

 

I tried to pic************* out of cottage cheese once. Then I decided the hell with it I don't eat cottage cheese anyway.


What we have here is your standard almost enough information. Glad to see that I have a little help carryibng this torch; that******* is getting heavy.

Ruty,
I actually set up a 2x4 intake [late edelbrock] with a pair of holley 500s once. Had one turned around backward. At a glance it looked like an oddball 4 bbl. Problem is that unless you have gone balls to the walls with your 4bbl a single holley 500 gets worse mileage than a standard 4 bbl in normal driving.

But it did make some folks scratch their heads and on an engine with a killer top end it would be a pretty slick setup.

 

The intake was the Edelbrock dual quad with 600 Edelbrock carbs. Heads were Merlin Oval Ports, the cam was an XE274H. My buddy's 427 ran the same intake set-up with GM rectangular ports heads and an L88 cam.

 

Just 2 add me 2-cents..........Ran factory two-four Set-Up in the 1960's.........270 h.p. (283) Chebie, Whlist a'courtin' Pretty Little Richie Rich Girl in Atlanter Ga............Oh, got off (tha' Subject ! )............
It ran off one carb, til you stuck your foot init,
Got 21 mpg Highway...........Was 325 mile trip one way.......an I was Running 4.11 gear in 3300 lb. '57 Chevy........Yeah'as, Duntov 097, naturally, with Headers..........
You'ens HAVE A GREAT WEEKEND !

 

My t-bucket doesn't weigh much but with one to one linkage on Offy low rise, two 600 Carters on a 355,th350 and 4.11 gears got 15.2 mpg. It was very lean on the front 4 when trying to run progressive linkage with the rear carb the main.
A vacuum secondary carb is a little more forgiving as it only gives you enough to compensate for the vacuum signal.

 

There's no reason you can't get decent mileage with 2x4 setup, if it's driven rationally and set up right. Of course the right cam and heads will help or hinder mileage, but high teens for mpg is very doable.
My .040" over 327 with tunnelram and twin 450 Holleys gets nearly 16 mpg with 3.73 gears, and it's not a mild cam. I could downsize to an RV cam and probably gain 2-3 mpg. No reason to block off or disconnect one carb.

 

Thanks everybody for the responce! I have reveived both pros and cons on the setup and I talked to my son who is in Afghanistan as it's his car and i'm working on it while he's there trying to get some work done on it before he gets back in May!

I think were going to go with a single 4 on it with a 600 carb, God, I wish they made a 3 duece setup for a 90 305 but they don't, belive me I have looked.

Thanks again for the info!
KJ

 

Are you refering to Vortec style intake with bolt going straight down or the fact that the runners on the 3 duece intake not being large enough in length to cover the intake port correctly?

 

Bingo! Running a dual quad with only one working carb is Mickey Mouse.

 

Hey, Johnny Gee!
It's an FI engine, I have been told by every dealer there is not one made for this motor! KJ

 

That's because after 86' the center bolts on the intake to head are Canted or go in straight in an up and down direction. Other than that, that's it. #5419 from Edelbrock does say 55-86 as you say. But if you modify the center bolt holes you can make that intake work along with wedge shaped washers for those center bolts. Dealer's and Manufacture's won't tell you that it can be modified.

 

Thanks, JD!

How would you modify the holes is there someone on here thats done it that
has pictures?
KJ

 

this is a good*****ogy, i like where this is going. i'm following this thread. because i don't care HOW they got big, just THAT their got big. good work. good work.

 

All you need is a die grinder or barrow one. You just need to oval the hole. There are intakes out there that are done this way already from the manufacturer. Edlebrock being one of them on differant style intakes. They even come with the special tapered washer included in the box. Maybe locate a speed shop that has them to look at, or swapmeet to see what I'm talking about. Good Luck