Best 2100 size to use

StarDiero75

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Howdy guys,

With recent problems with my weber 32/36, I'm highly considering putting in an autolite 2100 since I plan to use that when i put my modified 1980 head on it.

My question is, they come in a wide variety, which is thr best to use on these engines?

A 1.01 comes off a 221 V8, so size is very similar

A 1.08 comes off most small block V8s, and this is the one I've heard is the best to use.

A 1.14 comes off 351s

Then the 1.21+ are big blocks

Would it be best to ise a 1.01 or 1.08? I'm looking for roughly same economy and slightly more power. But least work on jetting.

Thanks
Ryan
 

wsa111

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Ryan, till you install the 80 head, your A/F tester will be a valuable tuning tool.
The Autolite carbs can also use a Holley power valve.
If too rich at WOT you may need smaller PVRC under the power valve.
 

CZLN6

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Howdy Star:

Here are a couple more FYIs for you-
1.01 & 1.02 Were both used on 260 V8s
*1.14 were used on 1964 - '67, 289s and 302s
1.08 were used on 1968 -'73, 302s
*1.23 were used on 1967 to '70, 351s
1.21 were used on 1971 - '73, 351s
The stars(*) denote the earlier version and have different internals (K cluster)causing the later versions to run slightly leaner and cleaner.

All have annular discharge boosters. All are incredibly easy to rebuild. Jets are unique to Autolite except for the very earliest, from 1960 and earlier. They were Holley. Ironically, the Holley power valves are interchangeable with 2100 and are much more accurate and come in a wider variety. Stock power valves come with a rebuild kit. Most 2100s- 1.08 and earlier can be used with no changes (with the exception of cleaning and rebuilding) when adapted to a 200 engine. Slight variations to the accelerator pump arms may be necessary. 1.08s were used on a variety of vehicles with a 302 engine- from Falcons and Mustangs to F100s and Galaxies so internal adaptation was made by changing the internal K-cluster. So, for your use look for 1.01 or 1.02 from a Falcon for best internals for your situation.

Hope that helps you understand a few more details. Good luck.

Adios, David
 

bmbm40

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Very interesting information regarding the model numbers and the K cluster lean/rich operation. Good to know, thanks.
 

chad

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keep it goin, guys.
Close to another sticky?
Nice tech info for our carbs § ?
or 'sm block engine §" ?
 

StarDiero75

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wsa111":36fpth2v said:
Ryan, till you install the 80 head, your A/F tester will be a valuable tuning tool.
The Autolite carbs can also use a Holley power valve.
If too rich at WOT you may need smaller PVRC under the power valve.
Its a wonderful tool. It's just gonna drive me crazy till i get the carb all tuned haha

So in your honest opinion, should i ditch the weber 32/36 and go to the 1.01 Autolite? I want something more user friendly.
 

StarDiero75

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CZLN6":2641azfh said:
Howdy Star:

Here are a couple more FYIs for you-
1.01 & 1.20 Were both used on 260 V8s
*1.14 were used on 1964 - '67, 289s and 302s
1.08 were used on 1968 -'73, 302s
*1.23 were used on 1967 to '70, 351s
1.21 were used on 1971 - '73, 351s
The stars denote the earlier version and have different internals (K cluster)causing the later versions to run slightly leaner and cleaner.

All have annular discharge boosters. All are incredibly easy to rebuild. Jets are unique to Autolite except for the very earliest, from 1960 and earlier. They were Holley. Ironically, the Holley power valves are interchangeable with 2100 and are much more accurate and come in a wider variety. Stock power valves come with a rebuild kit. Most 2100s- 1.08 and earlier can be used with no changes (with the exception of cleaning and rebuilding) when adapted to a 200 engine. Slight variations to the accelerator pump arms may be necessary. 1.08s were used on a variety of vehicles with a 302 engine- from Falcons and Mustangs to F100s and Galaxies so internal adaptation was made by changing the internal K-cluster. So, for your use look for 1.01 or 1.02 from a Falcon for best internals for your situation.

Hope that helps you understand a few more details. Good luck.

Adios, David
That is pefect man, thats good info. It helps, I'm already on the lookout for the carb
 

cr_bobcat

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I would go with the 1.08. I loved the 1.14 I had on mine, right up until I cracked one of the feet off. Don't over tighten those old carb bodies....
 

Econoline

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I had a 1.08 from a 72 302 I was going to use on my 250 until I decided to go tbi.
 

CZLN6

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Howdy back Star and All:

FYI- The K cluster is responsible for rich/lean of the idle curcuit, transition circuit, and accelerator pump volume. That leaves the low speed idle air screw and the accelerator pump linkage externally to tune. K clusters are marked with a coded stamp to a specific vehicle/engine application. A 1.08 destined for an F100 to Iowa would have a K cluster very similar in appearence to a 1.08 for a Mustang going to Arizona, but internally would be very different. We have found no key to the FoMoCo stamped code on the bottom of the K cluster. So, swapping the K cluster, for refining the tune is a shot in the dark, at best.
For all of the 2100s simplicity and beauty of function, fine tuning, to a certain extent, is limited.

Ironically, we have swapped on a bunch of different 2100s, 1.08s and 1.14s to my 250 and to Dennis' 200 and they all worked fairly well- dirt and all, no rebuild. Other than not being able to find main jets to play with the Autolite 2100s are great. And they weigh less than Holley 2300 and have no gasket line below the fuel bowl.

PS- Autolite jets are not numbered the same way Holley jets are. Another mystery.

Adios, David
 

StarDiero75

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CZLN6":hfynl56w said:
Howdy back Star and All:

FYI- The K cluster is responsible for rich/lean of the idle curcuit, transition circuit, and accelerator pump volume. That leaves the low speed idle air screw and the accelerator pump linkage externally to tune. K clusters are marked with a coded stamp to a specific vehicle/engine application. A 1.08 destined for an F100 to Iowa would have a K cluster very similar in appearence to a 1.08 for a Mustang going to Arizona, but internally would be very different. We have found no key to the FoMoCo stamped code on the bottom of the K cluster. So, swapping the K cluster, for refining the tune is a shot in the dark, at best.
For all of the 2100s simplicity and beauty of function, fine tuning, to a certain extent, is limited.

Ironically, we have swapped on a bunch of different 2100s, 1.08s and 1.14s to my 250 and to Dennis' 200 and they all worked fairly well- dirt and all, no rebuild. Other than not being able to find main jets to play with the Autolite 2100s are great. And they weigh less than Holley 2300 and have no gasket line below the fuel bowl.

PS- Autolite jets are not numbered the same way Holley jets are. Another mystery.

Adios, David
Very strange, so its more or less luck with testing K clusters?

I'm looking for simplicity so this sounds like the carb for me. The weber is a nightmare.

I do have a 1.23 i got off a 360, and i love how simple it is. Simplicity is a beautiful thing.
 

StarDiero75

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Just bought a 68 2100 1.08 off a 302 from eBay. Hopefully its good. I'll look into getting the holley/autolite adapter from VI now. I gotta also swap to a cable pedal as i dont think the mechanical pedal will work anymore
 

xctasy

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I enjoy Real People who do Real Stuff and get there hands dirty! Ryan, great work.

The typical Theoretical Engineer who got his hands dirty is the ex Limey David Vizard. He found that 1.19 vs 1.38 (350 cfm 2bbl vs 500 cfm 2bbl), the kick in was at just 125 hp net at the flywheel. Result? Another 10 hp net. The 1979 2.8 Mustang got given a 1.14 2150 Motorcraft over the 32/36 based Autolite or Motorcraft part numbered 5200. Some where, another 4 hp , depending on what figures you garner.
The average venturi size of a 5200 is exactly 1.01. The reason it gives strange air fuel ratios is the primary and secondary circuits augument air fuel supply. The carb on the 2.8 was well sorted.

My vote is for the old 1.23 with s two stage power valve and you play with the PVCR's with either Bills E string, fuse wire or Sean Murphy style hex plug and fine drill holes.
 

chad

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Good ol Mike's.
Not sure if U wanna look here but there's several threads on 'goni cable' w/o the Lokar.
(how 2 bend the pedle's arm, attach to fire wall, link it up on the carb...
 

wsa111

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xctasy":21glf6r8 said:
vote is for the old 1.23 with s two stage power valve and you play with the PVCR's with either Bills E string, fuse wire or Sean Murphy style hex plug and fine drill holes.
The orifices under the power valve can be drilled all the way & tapped close to the length of the 6-32 brass hex set screw.

They can be purchased at McMaster Carr. They come blank & you have to drill the desired orifice size yourself.
 
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