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View Full Version : I wonder, 4bbl the weber DCOE way



Magny
06-13-2005, 09:23 PM
would this work for our cars???

http://www.jameng.com/products/images/021000202.jpg

mmmmmmmmm...............4 barrels lol

but yeah just wondering lol

88accordalltheway
06-13-2005, 09:58 PM
i freakin wish!!!

phrenology
06-13-2005, 10:15 PM
would this work for our cars???

http://www.jameng.com/products/images/021000202.jpg

mmmmmmmmm...............4 barrels lol

but yeah just wondering lol

It will if you mount those DCOEs on the right intake manifold for the A20. It looks fancy but its just two Weber DCOEs with fuel pressure gauges (or regulators) mounted on a downdraft manifold for replacing a (Holley or other) 4 barrel downdraft carb. Personally I'm not sure why you would want to do a set up like that, it kind of defeats the purpose of using sidedraft carbs. I guess when you have a V8 set-up you have to set em' up like that or use a manifold for 4 DCOEs ported to each cylinder, its still a bit restrictive. Ask Rjudgey he's the Honda-Weber man...or PhydeauX.


Badass Webers on Spitfires (http://triumphspitfire.com/images/engine/Schumanneng2.jpg)

Webers on Everything from Honda to Lambos (http://www.piercemanifolds.com/yourwebers.htm) :rockon: :devil: :rockon: :devil:

A20A1
06-13-2005, 10:57 PM
Do you really what to know?

You can use it... but not with all 4 barrels exposed to all 4 cylinders though. It's too much carb for our small motor. I'm splitting a 4bbl to use on the A20.

I think that maifold you posted is more for show on a V8... and it allows the use of air horns with filters without cutting a hole in the hood. Nice low profile.
http://www.3geez.com/attachment.php?attachmentid=3486
http://www.3geez.com/attachment.php?attachmentid=3487
http://www.3geez.com/attachment.php?attachmentid=3882
http://www.3geez.com/attachment.php?attachmentid=3881
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FyreDaug
06-14-2005, 04:05 PM
Just curious because I dont know myself, but what if the carb put on the engine was too big for it? What kind of issues do you get? I'm sure it can be tuned and you can probably get normal 100% throttle out of like 60% out of a bigger carb, anything else would be too much right? If you know what I mean...

A20A1
06-14-2005, 06:08 PM
I think I see what you mean and there is a way to use only what the engine requires when you switch to a larger carb, but it doesn't always work out.

Lets say you had a 4bbl with a Vacuum Secondary as opposed to a Mechanical secondary. The Vacuum secondary will only open if the demand of the motor can pull it open so the throttle is fairly balanced along with the demand of the motor.
On a side note it would be better probably in that instance to have rather small primary barrels like on our stock carb and much larger vacuum operated secondaries.

Now if you ran with mechanical secondaries you let in more air as the secondaries open reguardless of the engine demand.
This excess air flow could cause problems since you're distributing the air flow past the venturies in such a way that there is no longer enough pull / venturi vacuum to effectively get the correct fuel mixture.

Fuel needs the a drop in pressure in the booster venturies for fuel to flow into the barrels, with 1 barrel all the engine demand creates a very strong drop in pressure in that one barrel. When you add another barrel that drop in pressure is distributed among the 2... add 3 barrels and the singal drops even further, add 4 and you'll still flow air but the pressure drop at each of the barrels might not enough to pull out the correct amount of fuel. Thats why too big a carb is bad.

My manifold divided the carb so that the vacuum signal / pressure drop is not distributed among all 4 barrels but rather 2 barrels per 2 cylinders.