RE: SPICA pump gap setting

[Hirsch <Catenary@xxxxxxxxxxxxxx>]

Bruce Giller wrote:
> I'm confused. I've read the AROC SPICA manual and it seems to
> be a history of all relevant notes about the SPICA pump from
> the time it was introduced until now. And I've found
> contradictory instructions on how to set the pump gap
> correctly from both ALFA themselves and AROC members.

Here's my impression of how it should be done:
1) Use dummy actuator (DA) set to correct length for year
of car to set pump gap to 0.019in. (Long link disconnected.)
2) Test TA and shim so shim plus TA length at 68 deg F is
23mm +- 1mm.
3) Install TA and adjust long link to reestablish a pump gap
of 0.019in.

I found Appendix 5 in the Spica Tech Notes to be most helpful
in explaining the setup procedure This ARI doc covers cars
'70 thru '79. =


As to using an in-spec TA to adjust the pump gap, this is what
the Oregon AROC Club website's Spica tuneup instructs. The site
is at  www.alfaclub.org  and in the section, "Adjusting the
Thermostatic Actuator screw" it states:

   "With the engine (and thermostatic actuator (TA)) at
   operating temperature, disconnect the long rod from the
   bellcrank. Measure the gap between the lever at the back
   of the pump and the reference screw. If the pump gap is 0
   to 0.019 inch, the TA screw is adjusted correctly."

As stated earlier, this procedure uses the TA to set the pump
gap. Unfortunately, David Rogers, National Service Operations
Manager, ARDONA, warns against just this practice. On page 168
of the AROC Spica Tech Notes, Rogers writes:

   "The adjustment of the cam centering screw (with a specific-
   length dummy TA in place) IS THE ONLY WAY to synchronize the
   3D cam with the internal pump cold enrichment linkage. Due to
   the different model year 3D cam profiles, different length
   dummy actuators are incorporated, allowing the control lever
   to reference screw clearance spec (0.5mm/0.020") to remain
   uniform for all model years. This simplifies/standardizes
   the cam centering adjustment."

   "The use of a real TA to adjust the cam centering screw to
   achieve the specified clearance WILL NOT CORRECTLY SYNCHRONIZE
   the internal pump linkage with the 3D cam."

   "When the TA reaches operating temperature, the nub protrusion
   will exceed that of the correct dummy actuator. When this
   occurs, the 0.5mm/0.020" clearance at the control
   lever/reference screw is MAINTAINED BY THE CORRECT
   ADJUSTMENT OF THE LONG CONTROL ROD, NOT THE CAM CENTERING SCREW."

   "With a warm engine, the long control rod disconnected, and
   the real TA in place, the control lever to reference screw
   clearance should be NOTHING (0.0mm/0.000in)."

My interpretation of ARDONA's position is that it is wrong to
set the pump gap by adjusting the TA screw using a real live
TA. The correct way to set the pump gap (0.019in) is to use
a dummy actuator set to the proper length based on your model
year. (In either case set the pump gap with the long rod
disconnected.) Then, once at operating temp, adjust the long
rod to re-establish a 0.019in pump gap. =


Good luck

Rich Hirsch
'87 Milano
'78 Spider
'67 Duetto
'66 Sprint GTV <- Catdaddy
Editor, i Saluti, St Louis AROC
Website: http://www.catenary.com/victor/isaluti

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