[Fot] Weber DCOE 45's on TR4

[TR4Tony]

Peter

I have had and dealt with this issue on BST82B, which has 1990's vintage 
Spanish origin Weber DCOE 45 152's with the three progression holes. Exactly 
this 'pickup' problem, which is a big issue on a rally car with lots of 
short, sharp moves where the full rev range is used, much more so than a 
race car (except from initial launch!).

WEBCON in the UK can set each carb in a jig and drill the missing 2 holes 
accurately for about #50 a carb (phew!) but it does the job nicely. I dare 
say you can do this at home with a decent pillar drill and a plate mounted 
jig.

The DCOE 45 152G carbs now sold have 5 progression holes (WEBCON tell me 
that these were developed for the Zetec engine), so if anyone is buying 
carbs those are the ones to look for if its a TR application. the plain old 
152's only have 3 holes.

The DCOE 45 09's on 3VC (Ex Works TR4) dont seem to have this problem but I 
havent checked yet to see how many progression holes. The other ex works 
carbs I have show 4 holes, the 3rd past the critcal point you note, but the 
car these came from was rallied hard in the USA so maybe they were added 
after manufacture.

There are a couple of people here in the UK that I can point you at for some 
serious technical advice if that will help.

Happy new year.

Tony
----- Original Message ----- 
From: "Peter Vucinic" <pvucinic at netspace.net.au>
To: "FOT" <fot at autox.team.net>
Sent: Friday, January 02, 2009 1:38 AM
Subject: [Fot] Weber DCOE 45's on TR4


> Dear Lister's,
>
>
>
> I am seeking those people who have had experience with 45mm WEBER DCOE's
> fitted to TR3/4 engines.
>
>
>
> Specifically those that have modified the progression circuit holes to
> remove problems such as 'stumbling/hesitation' and having to run 
> excessively
> RICH idle jets to overcome 'stumbling/hesitation'. I suspect this issue 
> will
> more relevant to those of us who run road cars, rather than race. But it 
> is
> as equally relevant to those who race. It appears that the problem is 
> found
> with those of us running modern DCOE 152's with 78 Degree throttle plates.
> But not limited to this model. DCOE 152's have three progression holes 
> that
> are all position FORWARD of the throttle plate.
>
>
>
> When you look at the throttle plate position (remove progression hole plug
> in top of carb), it is behind the first progression hole and NOT directly
> over the plate. This means that when acceleration begins, the top of the
> throttle plate, moves forward towards the ram tube/air cleaner side. The
> throttle plate then covers the first progression hole as the throttle 
> plate
> moves forward.
>
>
>
> My question is, has anyone drilled other progression hole(s) so that 
> it/they
> are positioned directly above the throttle plate?
>
> I suspect the 'period' DCOE9's will have different progression holes and 
> or
> positions.
>
>
>
>
>
> Kind Regards
>
> Peter Vucinic
>
> TR-4
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