If you're building a car from scratch that will have a shortened drive
shaft, why use the Alfetta drive shaft and Guibos AT ALL? I'd
fabricate a torque-tube (which Alfa SHOULD have done with the Alfetta
design in the first place) and dispense with the troublesome guibos.
This simplifies everything. The engine and transaxel move together as
a unit (rather than independently) and no U-joint is required. This
means that the shaft can be one piece, significantly lightened, and
balanced only once, and that's just before assembly. The heavy drive-
line is what I blame for the Alftetta line's poor throttle response
when the clutch is is disengaged or the tranny is in neutral.
George Graves
'86 GTV-6 3.0 'S'
On Jan 31, 2010, at 2:53 AM, The Baylys wrote:
I too have seriously considered a couple of different spaceframe
designs utilizing a variety of Alfa donor drivelines. I got to the
stage of parting out an Alfetta sedan and laying out the components
on the garage floor to mark it all out. I offer the following random
and raving comments, but caution that my memory may not be 100%
accurate:
1. If you are building a 2-seater, and especially if the design
has a high profile (i.e. replica 1930s style) then you should be
able to considerably reduce the flywheel-to-transmission distance of
an Alfetta driveline. This allows you to shorten the propshaft,
maybe to the extent of only needing one half (propshafts are
different lengths in coupes Vs sedans so may be able to mix-n-match
rather than cutting and welding). If you are seated back towards
the transmission, you can also fabricate a much better gearchange
system. The combination of short propshaft and more direct shifter
should yield very good results.
2. To give you an idea of how this would work, imagine sitting in
the rear seat of an Alfetta coupe, but having the steering wheel,
dash and pedals all in reach. In fact one could probably come up
with a design where the flywheel connects directly to the
clutch.......but this would be the same as a 105 driveline with a
bunch of disadvantages, so you'd be better off just using the 105
setup to begin with..........
2. There should be no need to use an Alfetta bellhousing on the
115 engine. It only serves as a rear engine support and it
shouldn't be difficult to fabricate a plate to bolt to the rear of
the engine to connect to the chassis. I would do all I could to NOT
use the Alfetta housing, even if only to make changing guibos easier.
3. Depending on the body design, you may be able to have the
pedal box and your feet well forward and beside the engine block.
This will further assist in shortening the overall design.
4. My RHD design used an inverted LHD steering rack situated
forward of the sump, connecting to modified Alfa 75 steering arms.
The 75 ( Milano) arms are removable whereas the earlier Alfetta
items are all cast as one piece. The inverted rack is needed
because moving the steering arms from behind the axle line to in
front of the axle line means a standard rack would make the car
steer the opposite to your inputs. This would take some time to
master.............. ;-)
5. The simplest design would utilise a standard 105/115
driveline, and there are a few Clubman style (Lotus-7) cars using
exactly that. There are also a couple of Alfetta based cars, but
the low floorline is a problem when trying to design around the
Alfettas massive clutch housing. Have you considered an Alfa
engine, Alfa DeDion suspension, and a Japanese transmission and diff?
6. Another option is to design things so the hump for the Alfetta
clutch housing sits under your knee. This would allow a lower seat.
7. If you are set on using an Alfetta rear end, why not buy a
GTV6 or Milano junker and build a V6 version?
8. Alternatively, use a 164 engine/tranny and design a mid/rear
engined, RWD chassis around it. Basically design a cradle to hold
engine, tranny and rear supension, then you are free to design any
number of cockpits and front ends to simply bolt on.
My (stalled) plans for an Alfetta based homebuilt chassis ended up
at a vaguely 1750 Zagato body style (very vaguely!). The higher
floor and straight body lines simplifies the design and manufacture
considerably, both for the chassis and the bodywork (no complex
curves in any sheetmetal). Having the wheels external to the body
does make legroom an issue though, meaning that you need to sit a
little further aft. When I had the design bug, large diameter
wheels were only available for SUVs. Now of course lightweight 20"
wheels are all over, and this would help keep a 1930s influenced
design more in proportion. I've always found that the single
biggest aesthetic issue with the Quattroroute and MGTC replicas is
the small wheels.
A couple of good resources for this type of project are the Ron
Champion books (google Locost), The SpeedPro series of books
(particularly How To Build & Modify Sportscar & Kitcar Suspension &
Brakes), and if you can find an old copy, Racing and Sports Car
Chassis Design by Michael Costin and David Phipps. I have a library
full of other books but find these ones to be the simplest. Most of
the others are so detailed and offer so many options they scare me
off ever cutting or welding a chassis tube.
Don't search for perfection first time out or you will never
start.......
Good Luck!
Beatle
Alfaless in Oz --
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