Wizzrd1001@aol.com wrote:
> On my MG, the PO installed an SK Racing carb, a clone of the Weber DCOE, the
> air filter he was using was a Superflo, well, it was really dirty, and the
> bracket broke, so, it kept falling off and melting against the headers...I
> replaced it with an oval 3" high K&N Filtercharger or whatever
<snip>
Hi Ian, I hope you've gotten over your Mini-lust,
I don't know nothin' about that Jap poser for a Weber.
Having said that, how does the air get into the float chamber? On a real, honest
to Pope, genuine WOP DCOE Weber, there are three holes on the intake side of the
carb. The two big ones are pretty easy to figure out but the other one is about
3/8's of an inch and at the 11 o'clock position of the casting. This is the
required inlet for the float chamber. Cover this up and the car will run real
goofy. The filter housing on the K&N's that I use can easily be mounted upside
down and cover up the float breather.
Yes, K&Ns could screw up a motorcycle's tuning. Many of those carbs were another
type of 'constant depression' design that didn't have any oil in the dashpots.
They were carefully tuned to a comparitively very high-ouput motor. We don't
usually have to worry about high-output on our LBCs and, besides, the Weber
design can easily oblige increased venturi velocity. So I'd guess lean running
ain't the problem.
Also, make sure you didn't invent a vaccuum leak downstream from the carb --
like maybe to the power brake booster.
As for vibration, Weber recommends a vibration-aborbing mounting system on 4
cylinder engines when using the DCOE. This is a flexible gasket between the carb
and manifold, loose fitting, spring loaded attachment nuts, and a support rod
that goes down to the block.
The main attraction of Velocity stacks on Webers (or any other sidedraft) is
that they are attractive. They don't do much for performance except you can tell
really smart-sounding stories about how the air gets smoothed out going into the
carb. The original purpose of the velocity stack was to keep the 'gas cloud'
close to the carb when letting off the go pedal. With sidedrafts and a lumpy
cam, there can be some blowback in the carbs on deceleration and it was thought
that the velocity stacks will help corral the fog until you put your foot into
the motor again. Kept gas fumes out of the driver's bay. And they polish up
nicely.
I believe I have now consumed my entire allotment of witty advice for the whole
day.
--
Bob Allen, Kansas City, '69CGT, '75TR6, '61Elva(?)
"Diplomacy is the art of saying 'Nice doggie!'.... until you can find a rock."
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