Re:1600/1300 Cyl. Heads & other thoughts

[ReOriginal@domain.elided]

     The discussion about putting a 105 1600 head on a 101; it can certainly 
be done. Consider this though. The 1600 domed combustion chamber is made for 
a 78 mm hole(piston). The 1300 hole/piston is 74mm. From the side view, that 
would look like a mushroom top. Picture it? A mismatch on an Alfa makes me 
feel wierd so though this kind of retrofit can certainly be accomplished, 
let's talk about how to make it really work. There exists a 1300 cylinder 
head that came on a 1300 Jr. that is also made for a 74 mm bore that would be 
much better. It also benefits the motor by giving 33mm intake valves as 
opposed to 31mm as on the 101 car. Now that's not as big as the 35mm as on 
the 105 1600 motor but it ain't bad. You'd want to look for a 10530 motor. 
That's the motor that should  work. The head is also internally strenghened 
as it's considered a 105 too. There are only a couple people in the U.S. that 
have this kind of special head that I know of. If interested parties contact 
us off-digest we'll dig up the names.
     Regarding the info about the 1300 and 1600 GTA intake manifolds, valve 
size etc. I'd like to offer this. The carbs for both cars are 45mm bores. 
They both use 78 mm pistons. Yes, both! In fact the pistons are identical. 
That's like being the same. The parts numbers in the books are identical. 
What changes is the stroke. The valve sizes are identical, 40.5mm and 36.5mm. 
What made the 1300 GTA head work better on the 1600 GTA was the increase in 
fuel mixture velocity that occured when air is sucked though 45mm carbs into 
a 33mm +/- hole and then expanded again into a bigger compartment, the 
combustion chamber. The "competition" manual years ago even taught us how, 
with sketches, to sleeve down the 1600 intake manifold with an aluminum tube 
in each port and then reshape it to be like the 1300. Their "secret" being 
that if the in-rushing fuel mixture is squeezed even tighter in the 1300  
than in the 1600, it litterally "leaps" out of the manifold into the 
combustion chamber. The bigger the squeeze and "leaping" expansion, the more 
the temperature for that incoming fuel drops, again giving us more power. 
They were very clever or lucky to have discovered this.  And we benefit 
'cause they shared the info.
     My vote for the best GTV is the '69 GTV Jr. It had the ATE brakes , the 
highly strengthened front chassis not seen on the 1600's at all, the really 
cool "flying buttress" seats, the twin pod dash like the 1750's and a super 
sweet motor; that carbed 1300. It was and still is a really balanced ride. We 
never saw them officially imported here unfortunately, though a few did make 
it here. If you have one, smile a lot! If not, Scott Fisher's note that the 
best GTV is the one we have is right on.
     It somehow  just doesnt't seem right to put a bra on something that 
doesn't look more provocative because of it.
     Jim Clark wore his tires evenly 'cause he was always sliding the 
cars.Wheel drift is more precise. It's easy to imagine how everything wears 
evenly when you're always sliding. Take thee to a driver's school anywhere in 
your Alfa. Alfas are generally better at sliding controllably than most cars 
on the planet. Get thee sliding! It's  not for everybody, but if you go fast 
enough it will happen . The GTV's are especially adept. That's just on reason 
why we're still enthusiastic about Alfa after all these years; right?
     Re-Originals..........O.E.M....all over again 

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