I think it would really help clarify the debate on Weber vs SU if we could
all be more specific about WHICH Weber we mean- There is a big difference
between a single sidedraft Weber and a DGV Weber on an MG. It is my
impression that there are many more people who convert to a DGV than a DCOE-
yet the debate always seems to lump the two together. Apples and oranges.
That being said, on my last '78 B the original ZS was trashed, and sucked so
much air around the throttle shaft that you could actually hear it whistling
at certain throttle angles. After pricing new and rebuilt ZS carbs, and
considering simplicity and performance, I installed a header and a Weber DGV
downdraft carb. The car ran beautifully with the DGV right out of the box,
never required any adjustment after setting the idle once, with great
throttle response and very good economy.
My choice of carb was partly based on my experience running a DGV on a 2
liter Ford cammer putting out aroung 125-130 hp. I was able to do some very
socially unacceptable things turning 7500 RPM in a relatively lightweight
'72 Pinto...(There, I've said the "P" word ;-) )
Scott Pontius
yet another '78 B, now with 8 cylinders and fuel injection
Los Angeles
-----Original Message-----
Subject: Re: SU's vs Webers when converting a rubbernose
>On Tue, 24 Nov 1998 17:37:30 -0500 Steven Tritle <stritle@epix.net>
>writes:
>>Sounds more like SU's than Webers.
>>
>>Steve
>>52 TD
>>Mike Gigante wrote:
>>
>>> Webers just sound so much better :-)
>>>
>>> In addition, unlike SUs, they are "set and forget" - they don't
>>drift out
>>> of tune, and they are less prone to wear problems. If they are set
>>up
>>> correctly, they are wonderful.
>>>
>>> Mike
>>>
>>> -----Original Message-----
>>> From: Neil Cotty <neilc@tradesrv.com.au>
>>> To: MG Mailing List (E-mail) <mgs@autox.team.net>
>>> Date: Monday, November 23, 1998 10:01 PM
>>> Subject: SU's vs Webers when converting a rubbernose
>>>
>>> >Hi all,
>>> >
>>> >I've read quite a bit lately on SU's, Webers etc and I'm not sure
>>why there
>>> >are so many people out there with rubbernose cars converting to a
>>Weber
>>> when
>>> >they could convert to SU's. As far as I'm aware a single Weber
>>*may* have
>>> an
>>> >advantage at very high RPM's (3-5 bhp according to the Special
>>Tuning
>>> manual
>>> >with other mods) but SU's have the advantage lower down, producing
>>more
>>> >torque - at least thats what I hear from many racers and the books
>>I've
>>> >read - but essentially overall performance is similar - power band
>>is
>>> >different. If you own a single carbed B why not replace them with
>>dual SU's
>>> >instead of a single Weber? They leave more space in the engine bay
>>thanks
>>> to
>>> >the smaller intake, and are more 'original' than webers. They also
>>look
>>> >quite pleasant! I'm not bagging Webers (I'd love a pair of
>>sidedraft DCOE's
>>> >and a xflow head!) I'm just genuinely wondering why Webers are
>>chosen
>>> before
>>> >SU's. Is it a supply issue or one of 'perception', as Webers are
>>really
>>> seen
>>> >as performance carburettors..
>>> >
>>> >I'd like to hear some comments on this rubbernose issue. The Weber
>>route is
>>> >chosen far more often than the SU when changing from single carbs
>>to
>>> >increase performance (*without* other engine mods!! not talking
>>about head
>>> >work, headers etc) - I'd think you'd get similar performance by
>>going to
>>> >dual HS4 SU's on a std car. I've never experienced a late model
>>rubbernose
>>> >so I can't appreciate how 'impaired' they actually are. My GT is no
>>> >bahnstormer even as std with 94hp, in good nick with dual carbs, a
>>lot more
>>> >has to be done to improve it's performance! Heck even my A eats it
>>for
>>> >breakfast! <G> Yes, it really does.
>>> >
>>> >Cheers,
>>> >Neil.
>>> >--
>>> >Neil Cotty - Sydney, Australia
>>> >1970 MG B GT / 1959 MG A 1600 Mk1
>>> >
>>
>>
>>
>>
>
>
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