G'etta fastener torque: Antonio's query

[BEast750F@domain.elided]

> Antonio wrote:
>
> Hello,
> I have a 1960 Giulietta 101 spyder (but it has a 750 series engine with
> front mounted bell type fuel pump) and need a little help.
> Does anyone know the torque wrench settings for the water/fuel pump
> bolts, and for the rocker cover securing studs (not cylinder head
> bolts)?
> Also if anyone knows where I can get hold of specification data like
> this I would be really grateful.
> Best regards
> Antonio Caira
>

Tony,

I have a Giullietta 101 spider with a 101 engine and 750 serial numbers!  
Guess they were cleaning the shelves.  The hood tag on mine calls it a 
101.04.  What does yours say?  My chassis number is 1495.08126, and my engine 
number is 1315.010647.  How close was yours in production?

As far as torque goes, you seem to be concerned about the 6mmx1.0mm/thread 
fasteners (nuts) that hold things to the front of the engine.  I use the 
following guide lines for 8.8 nuts and bolts:

6x1.0 = 6.5 lb.ft. (0.9 mkp/ 9nm)
8x1.25 = 16 lb.ft. (2.2 mkp/22 nm)
8x1.0 = 29 lb.ft. (4.3 mkp/43 nm)
10x1.5 = 29 lb.ft. (4.3 mkp/43 nm)
10x1.25 = 52 lb.ft. (7.2 mkp/72 nm)

consistent values assume clean, oiled threads.

In practice, I can't remember seeing anyone torque a 6mm fastener.  It's 
usually "hand tight."  Should you have the tools (and an inch/pound device 
might be necessary for the smaller ones) it is good practice to see what the 
engineers think "hand tight" is.  Interesting, also, is the dramatic 
difference the thread pitch makes.

My practical advice for such things is this: not too tight!

The cam covers used to have cute plastic/rubber covered nuts (8x1.25, I 
think?) that were designed for fingers to use.  I believe they (the 
designers) wanted the cam cover to be held down finger tight.  The black 
plastic covers would break off, leaving only a place for a large allen 
wrench.  Later, the black plastic was discontinued and the nuts were edged 
like a coin for something to grip, and I think they meant fingers again.

Unfortunately, most if not, all have been overtightened.  The ability to use 
a large allen tool on these encouraged 1/2" breaker bars and such.  Finding 
these cam cover nuts in pristine condition is rare as many have been plied 
and vice gripped.  The mistaken notion that oil leaks could be remedied by 
overtightening is prevalent and now a startling number of cam covers are 
cracked in six places...

...not too tight!

Bill

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