The Ford Barn

40cpe · 11-20-2016, 08:14 PM

What is the diameter of the neck where the air filter sits on a Rochester 2G/2GC? Is it the same 2 5/8" as a 94, or something else? I need to buy an air cleaner for my 2100 but will probably change to a Rochester in the near future. At $150 I don't want to have to do it again.

Doug · 11-20-2016, 09:52 PM

Measured a 2GV that I have; 2 5/8"

tubman · 11-20-2016, 10:04 PM

They are 2 5/8" as the previous poster said; the problem is that they are secured by a center bolt so they don't have the area on the top to clamp an 8BA air cleaner to. I made an adapter out of 2 5/8" exhaust tube the bolted to the carb with the center bolt that provided enough area to allow the use of a "clamp-on" style air cleaner.

40cpe · 11-20-2016, 10:17 PM

Great info. Thanks to both of you
Gene

Ol' Ron · 11-21-2016, 01:42 PM

For those running the small 2GC, the throttle bores don't align very well with the intake and can cause some idle and low speed problems. This can be solved by bell mouthing the intake manifold. However, the added benefit of having a larger carb is lost. I bore the intake to match the 2GC. Now all the benefits of the carb are available.

40cpe · 11-21-2016, 02:17 PM

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Ron, I have the Mercury manifold on the car. I drilled an extra hole to mount the 2100 carb on it. If I have the manifold bored for the 2G, are the bores just enlarged or is there an off-set required to match the 2G bores? Also, I understand that the 2100 has more flow than a 94, where does it fit in the gap between the 94 and a Rochester 2G?

tubman · 11-21-2016, 07:08 PM

I bought a "Rotabroach" 1 7/16" cutter to bore out my manifold. Mine was an aluminum Canadian manifold, and it was a "piece of cake". I believe that it would cut a cast iron manifold with no problems. The broach cutter and the mandrel were about $150, but it was worth it. I've bought a bunch of these cutters over the past few years, and they are absolutely superior for doing things like this. Anyone who would like to do this to a Merc manifold, please PM me. For alignment purposes, I have an extra 2GC base that I bolted on to the Merc manifold so there was no problem with the centerline offset.

Ol' Ron · 11-21-2016, 07:17 PM

I'm not sure of the differance between the 2110 and the 2GC throttle bores. I place the throttle shaft base on the intake and mark it. I then level the intake on my mill and bore the holes. I don't tilt the head I just shim up the intake untill the level reads "O" Have an old $5 tool I've been using in the mill for years. I don't think you can bore a Ford intake out that far.

tubman · 11-21-2016, 07:20 PM

Quote:

Originally Posted by Ol' Ron

I don't think you can bore a Ford intake out that far.

You're probably right, but it worked with my Merc manifold.

40cpe · 11-21-2016, 07:29 PM

Thanks for the information. I have a retired machinist close to me that I'll get to do it.

Ol' Ron · 11-22-2016, 10:02 AM

I have no idea what the difference between the 2110 and the 2GC is. Probably not much. Some day I;ll run across the BIG 94, but they're hard to come by. The 2GC is much easier. I use the 2GC on the stock car engine on an early (33/34) intake by filling the Vac Brake port with JB weld and drilling the m necessary third mounting hole. The rules called for any carb that bolted to the intake. I bored the intake to increase flow and ran into the exhaust heater. I then installed sleeves amd plugged the exhaust ports. This ran very good. I then got another one and Hollowed out the intake and that ran much better. I still have that one.

11-20-2016, 08:14 PM	#1
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	neck size of a small base Rochester 2G carb? What is the diameter of the neck where the air filter sits on a Rochester 2G/2GC? Is it the same 2 5/8" as a 94, or something else? I need to buy an air cleaner for my 2100 but will probably change to a Rochester in the near future. At $150 I don't want to have to do it again.

11-20-2016, 09:52 PM	#2
Doug Senior Member Join Date: May 2010 Location: Central Texas Posts: 151	Re: neck size of a small base Rochester 2G carb? Measured a 2GV that I have; 2 5/8"

11-20-2016, 10:04 PM	#3
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,312	Re: neck size of a small base Rochester 2G carb? They are 2 5/8" as the previous poster said; the problem is that they are secured by a center bolt so they don't have the area on the top to clamp an 8BA air cleaner to. I made an adapter out of 2 5/8" exhaust tube the bolted to the carb with the center bolt that provided enough area to allow the use of a "clamp-on" style air cleaner.

11-20-2016, 10:17 PM	#4
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	Re: neck size of a small base Rochester 2G carb? Great info. Thanks to both of you Gene

11-21-2016, 01:42 PM	#5
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,859	Re: neck size of a small base Rochester 2G carb? For those running the small 2GC, the throttle bores don't align very well with the intake and can cause some idle and low speed problems. This can be solved by bell mouthing the intake manifold. However, the added benefit of having a larger carb is lost. I bore the intake to match the 2GC. Now all the benefits of the carb are available.

11-21-2016, 02:17 PM	#6
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	Re: neck size of a small base Rochester 2G carb? Sponsored Links (Register now to hide all advertisements) Ron, I have the Mercury manifold on the car. I drilled an extra hole to mount the 2100 carb on it. If I have the manifold bored for the 2G, are the bores just enlarged or is there an off-set required to match the 2G bores? Also, I understand that the 2100 has more flow than a 94, where does it fit in the gap between the 94 and a Rochester 2G?

11-21-2016, 07:08 PM	#7
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,312	Re: neck size of a small base Rochester 2G carb? I bought a "Rotabroach" 1 7/16" cutter to bore out my manifold. Mine was an aluminum Canadian manifold, and it was a "piece of cake". I believe that it would cut a cast iron manifold with no problems. The broach cutter and the mandrel were about $150, but it was worth it. I've bought a bunch of these cutters over the past few years, and they are absolutely superior for doing things like this. Anyone who would like to do this to a Merc manifold, please PM me. For alignment purposes, I have an extra 2GC base that I bolted on to the Merc manifold so there was no problem with the centerline offset. Last edited by tubman; 11-21-2016 at 08:07 PM.

11-21-2016, 07:17 PM	#8
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,859	Re: neck size of a small base Rochester 2G carb? I'm not sure of the differance between the 2110 and the 2GC throttle bores. I place the throttle shaft base on the intake and mark it. I then level the intake on my mill and bore the holes. I don't tilt the head I just shim up the intake untill the level reads "O" Have an old $5 tool I've been using in the mill for years. I don't think you can bore a Ford intake out that far.

11-21-2016, 07:29 PM	#10
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	Re: neck size of a small base Rochester 2G carb? Thanks for the information. I have a retired machinist close to me that I'll get to do it.

11-22-2016, 10:02 AM	#11
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,859	Re: neck size of a small base Rochester 2G carb? I have no idea what the difference between the 2110 and the 2GC is. Probably not much. Some day I;ll run across the BIG 94, but they're hard to come by. The 2GC is much easier. I use the 2GC on the stock car engine on an early (33/34) intake by filling the Vac Brake port with JB weld and drilling the m necessary third mounting hole. The rules called for any carb that bolted to the intake. I bored the intake to increase flow and ran into the exhaust heater. I then installed sleeves amd plugged the exhaust ports. This ran very good. I then got another one and Hollowed out the intake and that ran much better. I still have that one.