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Dual Carb Question/Weber question too

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Do webers come in the form of a single barrel also or are they all 2 BBl?

 

How the heck did they ever come up with the abbreviation BBL for barrel?

 

When utilizing dual carbs, they have to be exactly the same and also tuned or set exactly the same correct? I know on motorcycles they do but I don't know why I feel so stupid right now, I am asking. So if I put dual webers on my car, how come VW's can do it but some here say it's too much gas for our subes? They are approximately the same CC's. Or are they using smaller carbs? If I use 32/36's can't I just re-jet them so they are "smaller"?

I cannot remember exactly why, but using a carb that is too big just won't work. I think that it won't produce enough vacuum to work properly, or something like that. It actually results in running too lean with a carb that is more than the engine can handle. I'm sure they have single-barrel webers available, you would just have to figure out what size is correct for your engine.

Haynes has a weber book out that covers many of the webers available in addition to the DGAV 32/36. You'll find it pretty informative. The book I have is Haynes #393 which covers Webers to 1979; I suspect there are later versions available.

  • Author

And just where would I find this magical book????

I've come accross a couple dual carb options while researching ea81 performance mods. RAM Performance sells a Twin carb Mikuni Intake system for $849.95.

 

The FAQ at www.subspeed.com suggest the Weber 34 ICT, or similar, for the single port heads, but say require the fabrication of custom manifolds to mount. (I wonder if you could adapt them to the Asian market OEM dual carb manifold?)

  • Author

I already have the dual carb manifold (For EA81) and the stock carbs with it. I wonder if I can just call or email a place that deals with webers and give them the type and part number and they can give me an equivolent weber for each carb. I would still have to get some cam work done and heads and maybe a few more tricks up the old sleeve. This probably won't happen for quite some time though. Boz

the only problem(s) with dual carbs are these:

 

linkage, how will you work throttle brackets? mechanical linkage, or two accelerator cables?

need to split the fuel lines, fuel return lines... one of each for each carb.

 

need either a dual carb manifold (RARE) or to get two single or two double barrel carbs and fab up your own intake system.

 

need to run vacuum lines from both carbs/manifolds to even it out.

 

you could do a dual weber 32/36 or a dual 34ICT, but you'd either need a complicated dual intake setup with interesting routing for the coolant, or to build your own manifold with two carburetor bases. either way, lots of time and/or money.

 

If dual hitachi manifolds were only less rare, the world would live in harmony. (or at least, would be closer to world peace.)

 

oh, and I took a look at a two barrel off an old Mazda... and it looked nearly identical in mounting of that of an EA81... but I doubt it's a good performance upgrade... looks like same barrels.

Originally posted by PHATBRAT

I already have the dual carb manifold (For EA81) and the stock carbs with it. I wonder if I can just call or email a place that deals with webers and give them the type and part number and they can give me an equivolent weber for each carb. I would still have to get some cam work done and heads and maybe a few more tricks up the old sleeve. This probably won't happen for quite some time though. Boz

 

He's got the dual carb manifold (lucky bastage ;) ). If you know the manufacturer and model number of the stock carbs, you should be able to look up the appropriate Weber conversion. I'd poke around the Redline Weber website and see if you can find the stock carbs on a conversion table...

if you have the manifold, they should be the same mounting as a normal EA81 Hitachi... so you *could* do a dual 32/36... but of course you might want to go ahead with the rest of the engine upgrade(s) to really get something out of this.

 

I don't think a dual carb setup would really show it's full potential until people made the engine breathe better (better flowing exhaust, better intake system, ported... polished... good cams... ect.)

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