'08 Twin - H - dual 2bbl's

Ol racer

FYI

Just a thought for anyone with basic hand tools to consider modifying a Twin -H intake for dual 2bbl Carb's. Its hard to beat the Hudson Engineering Twin- H design with nearly equal runners & centered carburator placement dividing 3 cyl's for each carb. (Only drawback intake is cast Iron, not Aluminum)



I cut off both single bases then die ground out the holes bolting down homemade 1/4" adaptor plates drilled for two large Pontiac V8 Rochester 2GC Carbs. These carb's are one of the largest 2bbl's ever made with 1 11/16"butterflys, and can be drilled for Holley Jets. However, one could always utilize smaller carbs if their motor is not modified accordingly). The carbs mount sideways so stock Twin- H linkage can be utilized with slight bend.



At first I retained the center Heat section, but discarded to lighten for my application making a blockoff plate. The balance Tube needs retained. I have made 4bbl Intakes, but feel with the length of the block dual 2bbl's distribution flow may result in superior performance.



Just thought I would share the easy conversion.....

Ol racer

Twin - H - Intake Also drilled & tapped for NOS

super651

Chuck, thats the one that We will copy,later in year. May Not need a Turbo on the 308? This will make it come out of the gate quicker.

Hudsonly Rudy.

( we still like to get a little more out of the Hudson Built Engines ,they respond so Good as is )

Ol racer

Rudy,

Because of your success with the Turbo 262" I suggest continuing plans for the 308. Normal aspiration is good but 'forced induction' is much better, especially when driven 'freely' by exhaust..





I like Holley 500cfm 2bbl's but they have too large a base to easily adapt. Rochester 2GC with small base is next best.. Actually, learned when choosing carb's big isnt always better. Smaller carb's are more 'responsive' & large Carbs better for total HP...

[Deleted User]

I really, really like that manifold.



I've wished that a similar intake manifold was commercially available. I'd much rather have that manifold in aluminum than anything I've seen.



Rudy, are going to be building these for folks?



Mark

[Deleted User]

I really like the Weber/Carter DGV carbs. About 230 cfms each with progressive secondaries. They would sit opposite of the 2GC, but would work with Twin-H linkage as well.



I don't have a thing against the 2GC. I can deal with it.



The one thing I've noticed, is that 500 cfm gets hard to tune. I'd opt for 2 - 2 barrels of around 220-230 cfms each.



Mark

SuperDave

There are a lot of different Rochester 2GC's out there. The front feed ones are larger than the side feeds. Different size bases. The side feeds are early models. The front feed ones have at least 7 different venturis that I have actually measured. Some books say three. Parts are not always interchangeable on these carbs .. If you miss match some parts, you will loose the squirter function! All the front feeds use the same size cast iron bases with butterflys. The only acception to that are the ones with a governor. They are the same size but you don't want to use it.. there can be problems with the idle stop on some combinations, but that is a simple mechanical problem that can be easily worked around. Carbs can be drilled and tapped to use Holley Jets to increase your choices. The big block Pontiac, and Chevy trucks and school busses will have the largest venturis. If you really want a beeeg flow, find a Mercruiser (Rochester)air horn. It doesn't have the obstructions in the intake. They didn't have an air cleaner. only a simple clamp on spark arrestor.With the right combination of parts, it will flow right along with a Holley 4412.

I have lots of short track experience with these things and I have outrun many 4412 equipped cars with my 2GC. Makes 'em scratch their heads..

Never tried one on a Hudson, but I know it would do wonders in place of a single 2bbl.