Inliners International
Posted By: Chevelle292Wagon Carburetor base size chart - 11/04/17 08:53 AM
Hi,
Anyone know of a online chart of carburetor base dimensions?
Something like the engine swap charts.

At this point looking for the baseplate size of a Holley 5200 two barrel.

Thanks
Posted By: stock49 Re: Carburetor base size chart - 11/05/17 11:38 PM
Hi Chevelle292Wagon . . .

I find the articles over at The Carburetor Shop instructive. They have a nice write up on the differences in four barrel mounting flanges.

As for the Holley 5200 - I believe those were native on Fords. The flange bolt pattern is both wider and longer then a Rochester dual jet:

Holley makes an Adapter Plate image above.

No experience here beyond way to much time researching on the web . . .
Posted By: mdonohue05 Re: Carburetor base size chart - 11/06/17 01:14 PM
yes, holly 5200's were found on Ford Pinto's among others (also vega and a few others). They are a weber carb that weber licensed to holley during those years. They are a 32/36 mm progressive two bbl. They work pretty well on an inline motor, even with an adapter (2 to 1), better without adapters or the above adapter. Not sure of the dimensions, but not the same as any rodchester, or holley 2300 series 2 bbl. I like the 1974 model, threaded fuel inlet as opposed to the earlier pressed in brass nipple inlet. If you use them, make sure you install the carbs so that the main jets are pointed forward. The are installed in a corner of the fuel bowl and will uncover on hard acceleration leading to a big giant bog (ask me how I know, lol)

If you have a really modified motor, then its the DGEV 38 mm two bbl. larger then the 32/36, a little more expensive, and not a progressive carb. Not really adapter friendly because of their size. but runs like heck.
Posted By: 70Nova Re: Carburetor base size chart - 11/06/17 01:37 PM
>If you have a really modified motor, then its the DGEV 38 mm two
>bbl. larger then the 32/36, a little more expensive, and not a
>progressive carb. Not really adapter friendly because of their
>size. but runs like heck.

thats what I'm doing now, see my other thread from yesterday. Found a Weber 38/38 clone cheap, "Rally" something or another.

I feel it a little pointless to put a much bigger carb on a stock intake, choking it down to original size after the carb. Might help a little, don't know.

Its not easy to make the stock intake noticeably bigger, you quickly punch a hole into the exhaust chamber around it. Knowing this, I got a spare intake to learn more, and found a way to make it 46% bigger.... by using a steel sleeve once I made the hole a LOT bigger. Not for someone who is not comfortable doing metal work or paying a machine shop a lot of money, easily more than a new clifford or offy intake would cost.

Commercially available adapters are super cheap, but cast in a way that makes it impossible to make them noticeably bigger. They are tall too, which may cause hood clearance issues. The pattern mine has (Only one I know to be available everywhere) is NOT the same pattern as the Weber 38/38. It matches with the Rochester 2bbl and a few other domestic 2bbl carbs. Those might still work reasonably well, in a mild engine, even if smaller than the 38/38. I didnt care to find out.

Edit: isn't the 292 original intake bigger than the 230/250 intake?
Posted By: panic Re: Carburetor base size chart - 11/06/17 09:50 PM
AFAIK the Rochester Model B throttle bore for the 292 is 1-3/4", larger than the 230 although it uses the same #3 SAE flange.
Posted By: Chevelle292Wagon Re: Carburetor base size chart - 11/07/17 11:27 AM
More like I had in mind:
http://www.carburetion.com/adaptors.asp
Posted By: Chevelle292Wagon Re: Carburetor base size chart - 11/09/17 10:42 AM
Originally Posted By: 70Nova
Edit: isn't the 292 original intake bigger than the 230/250 intake?


I believe the throttle bore is the same on 194-292 manifolds.
The ones I have measure 1 13/16.

The 194 intake, however, has noticeably smaller runners.
see pic:
[img:center]https://imgur.com/bcmqYP9[/img]
Posted By: 70Nova Re: Carburetor base size chart - 11/09/17 03:29 PM
thanks, I have to compare mine
Posted By: 70Nova Re: Carburetor base size chart - 11/09/17 10:32 PM
Figures, I did all that work on the smaller intake laugh Should help velocity and low end though... haha.
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