Re: 1.8 crank in 2.0 engine, etc.

["John Hertzman" <johnhertzman@domain.elided>]

In AD8-0192 Jonas asked if the 1.8 (EuroAlfetta) crank which he has will fit
into a 2.0 litre 105 block?

Still in 192 Henrik Johansen replied "Yep it's a straight fit. Did that a few
years ago. You do need to drill a hole at the end of the crank in order for it
to accept the gearbox shaft"

Then in 196 Wille R. wrote "In AD V8 #192 the question about swapping cranks
from an 1.8 to a 2.0 engine. I have found that the 2.0 crank dous not fit the
1.8 block. The 2.0 is as I can see it somewhat fatter and the 1.8 block does
not accept this. Been there, done it."

Steve Spiers asked "What engine is this for?", and Wille answered "It is the
105 series bertone/Spider engines and the 116 Alfetta range. They share the
block but not the crank. The crank needs to be drilled fot the shaft from the
gearbox."

I, being a Bloody Yank who was never offered the 1.8 Alfetta, had always
assumed that the 105 "1750" 1779 cc, 80 x 88.5 engine was essentially the same
as the Alfetta "1.8" 1779 cc, 80 x 88.5 engine except for the transmission
pilot bearing drilling in the crank. The 105 1750 crank and the 105/115 2000
crank (and several associated parts) have different part numbers in the parts
books.

There was a thread on 1750/2000 crankshaft issues in AD7-539 through AD7-605,
starting with several questions from Peter Audet in Canada who mentioned that
"in April'99 European Car, an Alfa article says MOST 1750 and all 2000 cranks
were nitride treated. If some 1750's were treated, did this start with a
certain engine number?" Replies from Simon Favre and Les Singh agreed that
production cranks were not but that optional competition cranks were. Nobody
supported a contrary position. The parts books show only one 105 1750 crank. I
assume that the 1.8 crank would be nitrided.

BUT (and here is the main point) Les Singh also wrote "The 2000 GTV Veloce
nitrided crank cannot be used in the 1750 because the bore centres hence the
journal spacings are different." If this is correct (and with Les I assume it
is) then a 1750 crank won't work in a 2000 engine. There remains the
possibility that for the Alfetta 1.8 engine Alfa used the same bore centers
(US spelling) as the 2000 engine, in which case the 1.8 Alfetta crank cannot
be simply drilled to fit a 105 1750 block. (Crank-swapping issues in the US
are usually Alfetta 2.0 into 115 2000, or Alfetta 2.0 engine into an earlier
car).

Les also mentioned (in the same posting and in a later one on a different but
related topic) that the flywheel bolt drillings were different between the 1.8
and the 1750, which would be consistent with differences in flywheel and
attachments which show up in the 105 1750 and 105/115 2000 parts books. I
don't have any parts books covering the 1.8 or any other European Alfettas, so
I can't pursue that end.

One other distantly related crankshaft issue is that a few people have been
intrigued by the possibility of using the 67.5 mm stroke crank from a late
seventies Giulietta Nuova 1300 (1357 cc, 80 x 67.5 mm) in other Alfa blocks
with special pistons etc for various odd displacement class records, and the
bore centers questions could introduce problems for such projects.

John H.

Raleigh, N.C.

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