Re: Failure modes for starters

[JHertzman@domain.elided]

In AD7-508 Jay Mackro asks about the seriously different cranking speeds of
two two-liter engines in his cars, one a '76 and the other a swapped engine
which may be earlier.

>> OK, here's my bottom line question: is it possible for a 
starter or solenoid to degrade?  I know they can die outright, 
but can starters also wear in a way that diminishes their 
torque before they totally die?<<

I am not a starter expert, but my understanding is that starters degrade, but
solenoids should not have anything to do with it. I have never had an Alfa
(1300, 1600, 1750, 2000) which cranked "really slowly". Some difference, yes,
but not great.

>> Another possibility is simply that the engine in the Duetto 
is an from an earlier 2L, and as such, has the older starter
(1.1hp?), while the one in the spider is the type that has
the bracket at the front that attaches to the right motor 
mount (1.5hp?) Does that make that much difference?  We're
talking the Duetto just barely turning, while the spider
just spins and starts.<<

It is the starters after October 1975 which are 1.1 hp, with a 131 tooth ring
gear; the previous ones were .7 hp. with a 130 tooth ring gear.

All USA Alfettas had the larger starter; given the number of scrapped Alfettas
a good used starter might be cheaper than rebuilding the .7 hp. unit. It
should not be a difficult swap, but does require some grinding of the motor
mount, and can require slight clearance grinding of the engine block.

The basic installation is covered in ARI Service Bulletin Group 05 #02,
October 1975.

Stewart Sandeman, Technical Editor of "Alfa Owner" in the early nineties, said
in a September 1993 article that the ring gear must be changed also. The ARI
Service Bulletin does not mention this. Herbert Bridge, and his brother Jim
had investigated the gear-mesh question and found that the late starter pinion
had a sloppy (thus noisy and probably faster wearing) fit with the early ring
gear, but had never run into a serious problem on several which they had
converted. Jim Bridge did come up with a "fix" in the form of one eccentric
starter mounting bolt which moved the pinion and ring gear into correct mesh.
This, and the overall story, is covered in an article and addendum which Herb
wrote for "Velocissima", November and December 1993.

1750 owners should note that this three-bolt starter with 130/131 tooth ring
gear does not apply to their two-bolt 110 tooth ring gear cars without more
work-

Cordially,

John H. 
Raleigh, N.C.

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