Re: flywheel position

[Charles Slayman <Charles.Slayman@domain.elided>]

Paul,
	I thought the crank, damper and flywheel were independently (ie 
externally) balanced on the 4 cylinder aluminum block Alfas.  (Digest experts 
like John, Fred, Jim, Russ, etc please correct me if I'm wrong).  As such, the 
flywheel to crank orientation on your '72 Spider shouldn't matter.
	However, on the L-Jetronic Spiders, there is a trigger pin on the 
flywheel that must be aligned with #1 TDC.  I recently had the flywheel on my 
'89 L-Jetronic Spider lightened and lost the timing mark.  For those Digesti 
with L-Jet Spiders, I post these instructions in case you run into trouble 
yourself.  Here is the process I used to get the crank and flywheel properly 
aligned (Thanks to Tom Sahines, Bob Wandel and Larry Dickman Jr):

ALIGNMENT OF L-JET FLYWHEEL TO CRANKSHAFT
=========================================
	1)  With #1 at TDC, the crankshaft bolt hole with the recess in it is at 
12 o'clock (the other 5 bolt holes have no recess).  I'm not sure if pre-L-Jet 
cranks have this recessed bolt hole.  I can't think why they would.
	2)  The line or mark on the flywheel should be at 12 o'clock also (mine 
was machined off in the lightening process).   
	3)  Bolt the flywheel up with the trigger pin located at 2 o'clock when 
viewed from the back of the engine (ie the trigger pin is in alignment with the 
second bolt from the top bolt in the clockwise direction).  
	4)  The height of the trigger pin is even with the bottom of the ring 
gear teeth (I shimmed mine up about 4mm after the lightening process).  
	5)  I measured the clearance between the sensor and the trigger pin with 
a piece of clay once everything was together to verify.  Both the ring gear 
sensor and the trigger pin sensor have ~1mm gap (pretty tight, huh!)
	
	Bob Wandel also showed me a trick to prolong ring gear life.  The engine 
has a tendency to stop in one or maybe two locations.  So the starter motor 
tends to engage these teeth first.  If you look, you can see an uneven wear 
pattern where this engagement occurs.  If you rotate the ring gear (mine was off 
the flywheel) by 60deg or one bolt hole, then the starter will engage fresher 
teeth.  Granted, I have over 170K on my motor, and had to look really hard to 
detect the wear pattern.  But it's worth a thought (especially if there is no 
special crank-flywheel alignment on the Spica or Motronic Spiders).
	On a related topic, my flywheel has the special ring spacer insert 
between the bolts and flywheel (can't figure out what it does other than make 
sure the bolts don't bottom out) without anylocktabs.  You have to use Locktite 
to keep things bolted together.
	
Cheers,
Charlie S
'89 Spider
San Jose	



>From: "pi" <pi@domain.elided>
>To: <alfa-digest@domain.elided>
>Subject: flywheel position
>Date: Tue, 6 Nov 2001 21:42:05 -0800
>MIME-Version: 1.0
>Content-Transfer-Encoding: 7bit
>
>'Project Alfa' was on hold for awhile as I was waiting for the "economic
>boom" to catch up to me (I'm an airline mechanic). Well it doesn't look like
>the "boom" is ever going to get to me and the poor old Alfetta only has a
>few more months of life left in her so I'm putting 'Project Alfa' back
>together due to the need of having a car to get to work with.
>
>Anyway - enough whining. I had the engine balanced before I put it together
>and all the marks are there for the flywheel and pressure plate but I can't
>remember how to align the flywheel with the crank. There's a big "O" stamped
>on the flywheel. Does this line up with #1 TDC or something like that?
>
>this is a 1972 2 liter
>
>Paul Irvine  - Antioch CA
>72 Spider - 79 Sprint Veloce - 82 GTV6
>---------------------------------------------
>Project Alfa
>
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