Holley 1920 Replacement Question

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74desertduster

74desertduster

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Have a 71 Dart with a stock slant 6 and a Holley 1920 Carb on it.

Wondering if there are any carbs that will bolt up and go without any major mods other than the 1920?

Not looking for anything other than stock performance and the 1920 seems a bit difficult to deal with (at least from what I have read).

Mine is old and tired so I am gonna have to do something anyway.

Thanks

Brian
 
If you're not concerned about smog requirements, you can use the earlier Carter 1bbl's but they're not much better....
 
The Carter BBS was used on slant-6s from 1960-1971 in passenger cars, 1961-1974 in trucks. The Holley 1920 was used on slant-6s from 1962-1973 in passenger cars, 1966-1973 in trucks. There were many variations of both carbs across these year ranges; all of them will bolt up to any slant-6 1bbl intake, but the throttle hookups, vacuum ports, and other aspects are not all the same. In most years, there were Holley 1920 and Carter BBS carbs for most slant-6 configurations (displacement, transmission, vehicle application, emissions package, etc.); which carb any given car got was a function of what was in stock at the build plant.

Overall, the Carter BBS is the better design and the Holley 1920 is the cheaper design. There are certain aspects of the BBS that are objectively superior -- the pontoon front-hung brass float, for example, is better than the 1920's side-hung foam float, which can create stall-on-left-turn problems. And the 1920 has a bowl gasket always below the fuel level, a much more leak-prone design than the BBS, which has no such gasket arrangement. The main metering block in the 1920 will eventually get crudded up with corrosion that cannot be remedied or cleaned out. On the other hand, the BBS is subject to casting warp at the mating surfaces of the air horn and main body castings due to overtightening of the screws over the years, and the BBS uses a leather accelerator pump plunger cup that isn't as durable in today's alcohol-contaminated gasolines as the rubber diaphragm in the 1920.

At this late date, considering these design benefits and drawbacks is a luxury available only if one has the choice of a new BBS vs. a new 1920. That is not usually the case, so the best carburetor becomes the one that is in the best, least-abused condition. That may mean a Holley 1945, the carburetor model used from 1974 on up. Most of the 1945s were calibrated with lean jetting to squeak the cars past Federal emissions type approval tests so they could be certified for legal sale; this can be remedied with larger (standard Holley) jets.

"Remanufactured" carburetors are in almost every case a hopeless waste of money, time, and effort.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.
 
Good info, as always, thanks!

I may check out what is available in a 1945 instead of another 1920. Add it to my list....which keeps growing.

"If it was easy everybody would do it"
 
I'm not wild about the 1945 either. I agree with Dan, the best of a sorry lot is the Carter BBS if you can find one that some gorilla hasn't been twisting the screws. 2nd choice is the 1945 if you can get an early one with relatively little in the way of smog features and a distant 3rd would be the Holley 1920. Those things are a fire just waiting to happen.
 
Is there a lot of mods required if I find a 2bbl intake? I mean aside from switching the intake...linkage etc? How are carb choices for the 2bbl intake?
 
74desertduster said:
Is there a lot of mods required if I find a 2bbl intake? I mean aside from switching the intake...linkage etc? How are carb choices for the 2bbl intake?
Click to expand...

Yes, yes there is. Youll need the 2bbl intake, the matching exhaust manifold so you get the correct choke stove, the carb, air cleaner, kickdown linkage, choke and maybe even the throttle cable. Seems like alot of work to get a 2bbl when you can pick up some performance by just getting a 2.25 headpipe and matching exhaust.
 
cudamark said:
I'm not wild about the 1945 either
Click to expand...

It's a fundamentally better design than the 1920 in a fair number of ways. It has some drawbacks that are rather easily corrected; brass floats are available for it, for example.

the 1945 if you can get an early one with relatively little in the way of smog features
Click to expand...

Mmm...I don't quite agree here. The first couple years of 1945 (1974-5) tend to be more problematic than the '76-'77-'78-'79 items. About the only "smog feature" that you would need to even think about would be the idle enrichment valve, which was used to allow a leaner/faster-off choke. This valve can simply be capped off and ignored on a vehicle not equipped to control it.

the Holley 1920. Those things are a fire just waiting to happen.
Click to expand...

I don't know that I'd go quite that far. Yes, the bowl gasket design is dumb, but how many fires have actually been caused by it?
 
slantsixdan said:
It's a fundamentally better design than the 1920 in a fair number of ways. It has some drawbacks that are rather easily corrected; brass floats are available for it, for example.



Mmm...I don't quite agree here. The first couple years of 1945 (1974-5) tend to be more problematic than the '76-'77-'78-'79 items. About the only "smog feature" that you would need to even think about would be the idle enrichment valve, which was used to allow a leaner/faster-off choke. This valve can simply be capped off and ignored on a vehicle not equipped to control it.



I don't know that I'd go quite that far. Yes, the bowl gasket design is dumb, but how many fires have actually been caused by it?
Click to expand...
That's what I mean by early.....pre '80's. I haven't had any more problems with the first two years than the later ones. They all seem to have the "loose base" syndrome which translates into vacuum leaks and irratic idle problems. You have to take the thing off the intake just to tighten the screws. Plan on doing that just about every year.
I've bought about a dozen cars with slant 6 engines and carb related fires through the years. All but one had the Holley. The other was a Carter with the inlet fitting stripped. I've had many others that had a leaky Holley and for some lucky reason, hadn't gone up in flames.
 
Not looking to pick up some performance, just a more stable carb. All inputs appreciated. Don't think I would go the 2bbl setup anyway....more than I want to deal with for this engine.

Will keep the eyes open for a 1945....

Or the 360 and trans I really want
 
Gotcha....new. Is there a step by step for checking and adjusting the valve lash someplace? Wouldn't surprise me if it has never been done on this car. Thanks!

Found it on Slantsix.org.....thanks again...this thing is driving me nuts with vibration at idle, like a miss, but stranger.
 
I just installed a 1945 from a 74 dart on my 68 valiant after rebuilding it. Replaced the pos reman bbs and im very happy with it. smoother idle and doesnt run rich like the bbs did. only problem I had was a small mod to the choke rod.
 
Turned out the seat for the power valve had come un staked and was letting fuel constantly pour into the intake....good for easy starting but super rich. All fixed now and runs really well. Thanks for all the help!

b
 
Hello I'm new here aND im a new owner of a 74 dodge dart custom 4 door 225 slant 6 auto matic. in the morning's the car starts but then dies and when I crank it the second time it takes a second but it will run as long as I keep rpms up. then when I put it in gear to drive the car wants to die unless I'm very very easy on the gas. any sort of acceleration and the car stumbles coughs and dies. in neutral if you Rev it slowly it will Rev out good. I put new gaskets on the carb needle and seat fuel filter fuel line accelerator pump gasket. (Light blue grommet looking thing) the little check ball floats. the power valve needle is bent and hangs up. could the power valve assembly be my problem?
 
Your choke isn't working correctly. Put in a № 1234 Electric choke kit and wind up with a better choke that (unlike the original) is adjustable.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.
 
slantsixdan said:
Your choke isn't working correctly. Put in a № 1234 Electric choke kit and wind up with a better choke that (unlike the original) is adjustable.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.[/QUOTE

Thanks Dan I'll buy the choke. would the bent power valve have anything to do with it. I'm curious because it runs good for awhile then goes to stumbling and will barely pull itself
Click to expand...
 
Justin,

Remove the air cleaner cover and you can see the choke work. BTW, if you drop anything down the throat, don't run the engine until you recover it. The choke should be closed, with some spring force, when cold. The second the engine fires, the "choke pull-off" should get manifold vacuum to slightly pop the choke open (manual gives spec). If not, the engine will die from "too rich". After that, it will slowly open as the exhaust manifold (and electric assist) heat up to operate the coiled thermal spring. To check the pull-off, remove the vacuum hose, push the stem in, block vac port w/ finger and see if the stem stays in. Of course it will extend slightly until vaccum builds, but won't go out fully until you remove your finger. Also, check that the vac hose isn't cracked and goes to a port near the bottom of the carb.

To answer the earlier 2 bbl question, those were Carter BBD. They appear much more available since also used on most small block engines (318). I bought a new one on ebay for $25 a few years back (for my 65 273). The slant ones might differ slightly, though many here run ones for a small block. Also, look for the Holley "Econo-master" of the 1980's. I recall there was a BBD replacement. Some complained "too restricted" for a V-8, but might be perfect for a slant.
 
Another vote for a 1945. Replaced the 1920 on my '73 with a late ('84) 1945 in the summer of 2013 and it hasn't had to be touched since. Just remember they have their own specific choke and air cleaner.
 
The float was set to deep and it was flooding the car out. just thought I'd let you guys know and say thank you for the help. everything g seems to be working correctly now thanks again.
 
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