sliding block, SPICA et al

["Steve Schaeffer" <borrani@domain.elided>]

RE: Sliding Block
The reason I've heard most commonly for the front wheel wagging poise is, as
Mike Valant pointed out, the difference in roll center height, and
stiffness, front to rear.  I heard one story that the sliding block was not
the most pleasant solution, but was retained because it was Chiti's idea.  A
Panhard rod is the most popular way to lower the rear roll center, it seems.
There are plenty of vintage race GTV's out there, mine included, with the
standard T-bar arrangement doing just fine!  A locked rear end takes care of
wheelspin.

RE: SPICA  The story seems to go that Alfa used it in the US strictly to get
by emissions, it was not installed to make the motor more powerful, so I
wouldn't compare it to the 300SL, or Fuelie Vettes.  FI is more efficient
than carbs.  Scott Fisher went on to very nicely say what a black box SPICA
was for so many years.  True, it can't be tinkered with by so many backyard
mechanics, but once properly setup, you just keep your hands off of it and
it'll run in all conditions.  It doesn't have to be hot rodded to run
correctly, but if you do increase the breathing capacity of the motor, you
have to match the pump as well, see Wes Ingram.  After 20 plus years the
pump could probably use a rebuild, so get some cams and a HP pump from Wes
and you're set!  His '73 street GTV has just Euro cams and his HP pump, and
is among the nicest, fastest, smoothest I've driven.  I think everybody
knows a 1600 is about the thirstiest Alfa 4-cyl.

The GTV weight issue has been dealt with on this digest, did anyone catalog
it?  My '67 weighs 2150lbs w/half tank of gas, no driver.  There's less
metal in the front of a step-nosed GTV, even their hoods are less-gussetted.

Steve S.
Seattle, WA


> Any thoughts?

>Sliding block rear suspension?  I have no idea how it works or even, to
>any degree, what it looks like, but John Tipler's book on Giulia Coupes
>hints at some of the effects that it had on the car's roll center.  Are
>you using the sliding block, or have you stayed with Alfa's stock
>T-shaped trunnion as a diff locater?  I'd guess that, since all the
>Autodelta cars used the sliding-block rear and probably very few of the
>later ones do, that it has something to do with that.

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