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2 Re: DCOE

To: PilotRob@webtv.net
Subject: 2 Re: DCOE
Date: Fri, 10 Aug 2001 16:52:29 EDT
Cc: spridgets@autox.team.net
Cap'n Bob,

Yes, you could be mistaken.  Adopting the belt and braces approach I have 
just pulled the top cover from a 45DCOE and while it does indeed have 5 
screws (and the jet inspection cover) holding it on, nothing drops out when 
it is off whether the carb or the cover is shaken or not.  There is a ball 
bearing in the float needle valve but it can't and doesn't come out.  In fact 
it doesn't come out AFAIK even when the float assembly is removed.

SO

No balls drop out and no balls in the acc pump jet circuit.

I do agree you can lean back (but not excessively) the main jet circuit and 
go up on pump jets to get high rpm mixture strength balanced and said from 
the beginning the pump jet supplements the mains at high rpm.  I also said 
you should jet the mains and then the pumps.  Jetting lean on mains and 
supplementing on the pumps can be done but what is the point?  What you get 
is black smoke (and less power) every time you accelerate hard, a lean low 
power spoooooooooooootttttttttttttt, and power back up at high rpm which 
incidentally might not combine with the maximum peak power the cam is 
designed for.  You get cruise economy but the DCOE wasn't designed as an 
economy carb and to my mind defeats the object of fitting one.  I like to 
cruise at about 85 in 5th and be able to accelerate to over a 100 without 
having to drop into 4th or stamp on the throttle pedal.

The pumps stream fuel at the rear of the carb and not through the venturi as 
you originally described.  The main jet circuit feeds into the aux venturi 
and has to because if it didn't the fuel wouldn't be drawn into the air 
because no low pressure area would exist.

Daniel1312



In a message dated 09/08/01 19:45:01 Pacific Daylight Time, 
PilotRob@webtv.net writes:

<< Sorry, Daniel-

Me either, Daniel, but I haven't run a Weber in years so I am relying very 
much
on memory, I am afraid.

Could I be mistaken? Sure. But, I remember there being more than a few
things that could be opened on top of
a DCOE and I remeber the little "balls"
very well as I almost lost these two little
critters during annual "cleaning" more than once.

Take off the five screws holding on the
top cover and unscrew everything in site;
find the balls? Aha!!

 
 I had to be "short" on my last reply 'cause
 Seinfeld was coming on, and I cannot
 miss Kramer and/or Neuman!
 
 Do not worry about a "contest" of any sort
 here. I know you from the site and can
 accept an honest error, whether it be on
 my part or your's; no problem, either way.
 
 Now, I have not run a Weber since my
 "tuned" 1311 went away years ago and
 I replaced it with a stock SU equipped
 '67, which got a Judson later on. When
 this car got destroyed, I picked up my
 current 1098 (stock) equipped '61 Frog
 which is getting a Judson-tailored 1293
 and the Delrin-vane equipped overhauled
 Judson after initial run- in on stock SU's.
 
 So, I've been out of the Weber business
 for many years. So, could I be mixed up
 in memory after so many years? Sure!
 
 When dyno tuning my prior 45DCOE
 equipped tuned 1311, the operator-
 tuner weakened my main system for
 better economy and made up for slight
 leaness on the "top end" by increasing
 the size of the accelerator pump jet
 from 50 to 60; quite a difference.
 
 But, it worked on the dyno according
 to the CO readings, and cruise economy
 subsequently increased without any
 "drying out" on the top end. Got 60K
 out of that 100hp+ motor before it
 dropped a valve taking off gently from
 a stop lite one day.
 
 So, technically I may be wrong about
 exactly how the "balls" fit in to the
 entire scheme of things but in practice,
 there is no doubt in my mind that the
 accelerator pump circuit is involved
 in mixture strength at the top end of
 the rpm scale as high speed flow
 "pulls" fuel from this opening on it's
 way through the barrel into the intake
 manifold.
 
 So while operationally correct, I could
 very well be technically wrong? Yes!!
 
 Now, I am gathering up all my Weber
 stuff to send to Mike Maclean out in
 California. As I gather this stuff next
 week when I return home after my
 next trip with the airline, I shall no
 doubt find my old Weber books and
 shall look through them, accordingly.
 
 After which, I shall again contact you
 after "re-educating" myself, so to speak!
 In the meantime, there are two little
 balls in the little monster, for sure.
 
 I thought I knew their function, but I'll
 re-check as aforementioned.
  
 
 
 
 
 Cap'n. Bob
     '61 :{) >>



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