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Re: 40 DCOE numbers

To: millerls@ado13.com, spridgets@autox.team.net
Subject: Re: 40 DCOE numbers
From: Daniel1312@aol.com
Date: Mon, 1 Mar 1999 18:50:25 EST
Reply-to: Daniel1312@aol.com
Sender: owner-spridgets@autox.team.net
In a message dated 01/3/1999  8:52:21PM,  millerls@ado13.com writes:

<< 40 DCOE - This is all I know at the moment
 
 Choke - 28
 Idle jet - 45 F9
 Main jet - 115
 Emulsion tube - F16
 Air correction jet - 200
 
 Engine
 
 948 cc with 1098 cc head
 Kent street cam - 254 degree duration (in/out)
 LCB header
 Centrifugal advance distributor (Aldon Yellow)
 
  >>

Larry,

I don't think much to Pierce manifolds jetting.  My observations are:

The main venturi is incredibly small - but is not causing the problems (I
would put in at least 32mm,ok a 30 minimum)

The main jet size is probably about righ for the main venturi but I guessed
this much from the symptons you describe.

No one ever fits a 200 air corrector on an A-Series because it will lean out
too much at high revs (watch the revs over 6,500 and don't take it to 7,500 as
a precaution - I have no idea of what effect this size of air correcter will
have)  But, this is not likely to be the cause of the problems.

The emulsion tube is probably ok.

The idle jet is not in itself unduly large but it might be on the big side for
the 28mm main venturi - also from what you say the progression is poor (from
mains to idle)

You don't give details of the aux venturi but from what you say it seems ok.

The pump jets are located on the side of the carb but I doubt if they are the
problem either. But check that it does have some fitted!!!

Are you absolutely sure you have some air horns/trumpets/rams fitted to the
carb, also do they fit correctly - they should kind of sleeve the aux vent.

Check that the jet inspection cover is fastened down nice and tight (car runs
like a pig at mid range rpm and gets worse when it comes off altogether!!

In summary, although the calibration is less than ideal and somewhat peculiar
it would not appear to give the symptons you are experiencing (other than
maybe the idle jet is less than ideal).  Why not give A.P.T a ring and see
what they suggest?  Also check you have blocked off the vacuum advance on the
distributor (I assume the DCOE manifold doesn't have a take off).

Trust this helps.


Daniel1312

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