Re: [alfa] Weber (Was..SPICA Fuel System)

[George Graves <gmgraves@xxxxxxxxxxx>]

On Friday, September 26, 2003, at 03:49 PM, alfa-digest wrote:

> Date: Fri, 26 Sep 2003 13:31:31 -0700 (PDT)
> From: Richard Lane <srlane@domain.elided>
> Subject: [alfa] Weber  (Was..SPICA Fuel System)
>
> I haven't owned a Spica car and so won't comment beyond voicing my 
> concern at
> there being anything on my car that only two men in the country know 
> how to fix
> when it wears out.
>
> However, I do know a little about Webers:-
>
> George Graves said:
>
> > > be advised that Webers, while arguably the very best carbs 
> > > available, require
> a lot of fiddling to keep them running right.
>
> This is simply untrue. The reason so many are out of tune now is that 
> this myth
> is perpetuated, causing everyone (whether a "professional" or not) to 
> get their
> flat-bade screwdriver out and start twiddling screws. Beyond a quick
> synchronization check, as George described, at each oil-change (30 
> seconds to
> check, 30 more to adjust..when necessary),  there is no adjustment 
> necessary.
> Webers stay in tune too.
I also know a bit about Webers. I owned a Jaguar XK140 SC roadster with 
three 42mm dual choke side-drafts for a number of years, I also owned a 
Guilietta Sprint Veloce with two side-draft dual-choke 40mm Webers 
(IIRC), and I briefly owned a Ferrrari 212 Inter MM Berlinetta with 
three down-draft dual-choke 36DCF Webers. I took the time to learn 
about them. I agree that they don't require much in the way of 
"tuning", but I've never seen a multiple carburettor setup, whether, 
SUs on a Jag or an MG, Solexes on a Mercedes or an Alfa 2000 or 
multiple Webers on anything that didn't almost constantly wander out of 
sync. When I said 'fiddling" I was referring to synchronizing, not 
tuning. Although I must say that I did have mess with the idling screws 
on both the Jag and the Giulietta quite a bit. I found that the sync 
problem seemed to get critical every 3K or so. In those days we didn't 
have a fancy instrument like a Synchrometer to help us out. All we had 
was a pot-metal device with a pith-ball in a glass tube called a 
Unisyn. It was BARELY better than a piece of surgeon's tubing stuck in 
one's ear.



> and Sherwood White said:
> > > weber carbs destroy motors spica injection is the way to go
> They "destroy motors" do they? and the same poster later criticized 
> the "alfa
> club of america" for spreading misinformation....I subscribe to the 
> belief that
> Alfa Romeo knew more about building well-engineered cars in the '60s 
> than just
> about any other company of the day; and so their continuing with 
> Webers on
> no
> n-USA cars for a decade demonstrates that Webers do not "destroy 
> motors" at
> all.

Well, at least I know where this one started. High performance carbs 
tend to flood the engine with way too much gasoline on cold starts. 
Many exotic engines like those in Alfas, Maseratis and Ferraris needed 
a very rich mixture when cold or they simply either wouldn't start or 
idle properly. It was (and is) impossible to correctly meter cold 
engine mixtures on a carburetted car, so usually too much gas poured 
into the cold cylinders and the excess made it's way past the rings and 
into the engine oil where it diluted it and, eventually broke it down. 
Unless this oil was changed often, it accelerated engine wear. But 
anyone who owns a car that would have multiple Webers and who doesn't 
change the oil at about 2000 mile intervals, doesn't deserve the car. 
The key here is proper maintenance. It's true that EFI systems are MUCH 
better in this regard by properly enriching the fuel mixture on cold 
starts, but really, all it does is allow one to go longer between oil 
changes (all else being equal). But in this regard, SPICA is actually 
worse than carburettors. The SPICA pump shares it's lower-end 
"crankshaft" oil with the engine's oil. Since the pump pistons have no 
rings, a lot of gasoline gets past the pistons and into the oil. This 
requires that owners of SPICA'd Alfas change their oil often too, and 
between oil changes add Marvel Mystery Oil to their crankcases to 
offset the effects of having large amounts of gasoline in the oil.



> > > if webers wern't dirty therewould have never been spica and dirty 
> > > means less
> motor life in a nut shell next?
> Please don't confuse dirt that could destroy an engine with an 
> over-rich
> mixture from a badly-adjusted Weber.
>
> Those who admire the Spica system for its design-elegance (and it is 
> pretty
> amazing) would perhaps also enjoy the Weber's elegance once they got 
> one apart
> (definitely feasible for the amateur). It performs the same function 
> with about
> 1/10 the number of moving parts - and that's elegant too.
Webers are beautiful. Like many of the cars that used them, they are 
true works of Italian art. Before the advent of EFI, they were the best 
way to get power from an engine and they were far less troublesome than 
most mechanical fuel injection schemes (Rochester, anyone) In fact, 
4-two choke Webers on a Chevy 327 would give exactly the same 
horsepower as as Rochester mechanical FI system-375 horsepower. But the 
Webers were far less trouble. EFI is the best way ever devised for 
getting the correct fuel-air mixture to an engine, but I sure miss the 
soul-satisfying WOOSH! of air through the venturi's of a pair of 
twin-throat Webers when you put the hammer down whether on a 109 
horsepower Alfa Giulietta Veloce, or Ferrari 365 Daytona.

> Anyway...Spica? Webers? as a wise man often says, "Enjoy yours".
Agreed.


George Graves
86 GTV-6 3.0'S'
> - -Richard Lane
> '67 GTV with 2xDCOE (not converted)
> '68 Maserati with 4xDCNL
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