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Modifying holley 1920 1bbl?
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Author:  featherduster76 [ Sun Aug 05, 2007 6:00 pm ]
Post subject:  Modifying holley 1920 1bbl?
Anybody know any good mods to do to the holley 1920 1bbl carb? Like what jetting to mess with and having the throat polished??? or any other mods?
Or does anybody know anybody (trustworthy) to rebuild and or modify my carb?
Author:  BigBlockBanjo [ Sun Aug 05, 2007 9:36 pm ]
Post subject: 
Yes, they can be improved. :)
First you need to make sure you have a good "core".
I completely disassembled my carb, smoothed the venturi,(I think you can make it slightly larger, but I didn't)
The biggest thing I did was modify the fuel bar. Take a look:
http://www.mopar225.blogspot.com
I spent about 4 hours on the bar.
I left the stock jet in it, and the plugs are a light tan color. I may still put a couple sizes bigger in...just to be on the safe side.

I rebuilt the motor at the same time, so I can't say 100% how well it works. But I know it idles very good, starter turns twice to crank it, and it smokes the tires.
I'm happy with it, and I wouldn't expect any more from a 1-bbl engine.
Good luck!
BBBanjo
Author:  Charrlie_S [ Mon Aug 06, 2007 5:00 am ]
Post subject: 
Yes it can be done, but why would you want to? I did it to my "stock eliminator" carb, because I had to run that carb, per the rules. It was about 3 tenths of a second quicker in the 1/4 mile then a factory stock carb. I think it would be time beter spent, just installing a larger carb.
Author:  Aggressive Ted [ Mon Aug 06, 2007 9:24 am ]
Post subject: 
My 1920 has a round wagon wheel type spray bar/fuel bar.

As far as mods go, punch the gasket out a little bigger for the accelerator pump shot. Sometimes the gasket will partially block the hole and give you a week squirt.

My carb has a dual plunger set up. I bought new plunger lever arm. My old one was deformed and wasn't actuating the economiser circuit properly.

The third thing was to shim the power valve so it actually touched the lever arm. This can be done by JB Welding a washer on the end of the power valve or by using a thinner gasket on the top or a combination of both.

The last thing was to take the slop out of the accelerator pump linkage. It is in the stock location, but bent to take the sloop out.

Now the carb puts out a healthy pump shot for a real hard take offs and the accelerator pump is immediate.
For a one barrel, it acts more like a highly tuned two barrel or a so-so 4 barrel.
For having a 2.76 Posi and 235/60 14's in the rear , I can break the rear end loose pretty easy.
My carb was pretty much a slug, and a low performer. I am pretty happy with the way it responds and the good gas mileage.
My biggest problem is restraining my driving habits. It is a alot of fun to drive and is very spunky.
So don't give up on the Holley 1920.
Author:  SlantSixDan [ Mon Aug 06, 2007 10:08 am ]
Post subject: 
Quote:
My 1920 has a round wagon wheel type spray bar/fuel bar.
That's an Economaster carburetor, with annular-discharge venturi. These work well for fuel atomisation, though they do tend to limit airflow capacity through the venturi.
Author:  Aggressive Ted [ Mon Aug 06, 2007 10:29 am ]
Post subject: 
Quote:
That's an Economaster carburetor, with annular-discharge venturi. These work well for fuel atomisation, though they do tend to limit airflow capacity through the venturi.
SlantSixDan,

Do you know what years these Holley 1920 carbs were used on SL6's?

Do you know what CFM this style carb is rated at?

What is the CFM of the Carter BBD two barrel?

Is it true that the 2 barrel will provide 10 more HP?

Thanks,
Author:  featherduster76 [ Mon Aug 06, 2007 12:00 pm ]
Post subject: 
[quote="Charrlie_S"]Yes it can be done, but why would you want to? I did it to my "stock eliminator" carb, because I had to run that carb, per the rules. It was about 3 tenths of a second quicker in the 1/4 mile then a factory stock carb. I think it would be time beter spent, just installing a larger carb.[/quote]

Why? Because I can and #2 to weird people out :shock: Reason #3 is because the 1bbl intake is already there which means no expense to me, I just dont have lots of $$ even though Id have to agree that my time would be better spent upgrading. But Im scratching my head on this one going why not??
Author:  SlantSixDan [ Mon Aug 06, 2007 12:07 pm ]
Post subject: 
Quote:
Do you know what years these Holley 1920 carbs were used on SL6's?
The Economasters were never original equipment, they were aftermarket only, offered in the late '70s/early '80s as fuel economy replacement carbs.
Quote:
Do you know what CFM this style carb is rated at?
No.
Quote:
What is the CFM of the Carter BBD two barrel?
Don't have hard info on that.
Quote:
Is it true that the 2 barrel will provide 10 more HP?
Somewhere in that neighbourhood, yes.
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