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Discussion Starter · #21 ·
I agree with all the above, primarily that I should look into making a torque plate. I am switching machine shops as all the other shops here in the Carlsbad area seem to have closed, and my new machinist is not an Alfa guy. I will meet with him tomorrow and see how he wants to handle it. It is getting hard to find anyone who wants to do anything "hands-on" these days. I can't recall the last time I met a restoration shop owner who didn't have grey hair.
 

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Discussion Starter · #22 ·
Hi Koenraad,

Neat trick with the 10 mm spark plugs, I had never thought of it. I opted to use off-the-shelf parts on this build in an effort to keep the cost down. I used 1 mm oversize intake and exhaust valves with stock stem diameters so I could use stock guides, seals, retainers, locks, shims, etc. The 1 mm oversize valves fit on the stock valve seats as well. If the engine output on the dyno is disappointing when I am done, the first place I would turn to try to make more power is the head, but I hope it doesn't come to that.

FYI, my cylinder head man told me that he can get better flow out of a 1750 head than a 1600 head. I believe that Mike Sperry of Sperry Valve works told me the same thing 30 years ago. The guy I bought my used engine parts from told me I could have either one for the same price, so I picked the 1750 head. The better flow thing might just be an "old wives' tale", but I figure the chambers might be shaped better for matching up to my 80 mm bore.

Rob
 

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750 Sprints, 750 Spider, 101 Sprint, 101 Spider, 101 Ti, 105 Sprint GT, 105 Juniors, others
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I put a 1600cc into my '60 Spider Normale, tweaked the head a bit by matching ports etc, my extremely talented engineering friend built me a 1600 Veloce branch for it, we sorted cams till we had a nice non-matched pair, a 1750 Euro 00548 on the intake and a 1600 Giulia Sprint GT 00502 on the exhaust, fitted twin Webers & a full Veloce intake system. The cams give it such a nice spread of mid range torque and it pulls like a steam locomotive. Owners of proper Giulia Spider Veloces are smiling as they've known this all along....

1300 is oiled & wrapped up under the bench.

Ciao
Greig
 

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Hi Koenraad,

Neat trick with the 10 mm spark plugs, I had never thought of it. I opted to use off-the-shelf parts on this build in an effort to keep the cost down. I used 1 mm oversize intake and exhaust valves with stock stem diameters so I could use stock guides, seals, retainers, locks, shims, etc. The 1 mm oversize valves fit on the stock valve seats as well. If the engine output on the dyno is disappointing when I am done, the first place I would turn to try to make more power is the head, but I hope it doesn't come to that.

FYI, my cylinder head man told me that he can get better flow out of a 1750 head than a 1600 head. I believe that Mike Sperry of Sperry Valve works told me the same thing 30 years ago. The guy I bought my used engine parts from told me I could have either one for the same price, so I picked the 1750 head. The better flow thing might just be an "old wives' tale", but I figure the chambers might be shaped better for matching up to my 80 mm bore.

Rob
I think you will find the 1600 and 1750 combustion chambers identical with the exception of a very small chamfer at the interface on the 1750.
 

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... The better flow thing might just be an "old wives' tale", but I figure the chambers might be shaped better for matching up to my 80 mm bore.
I checked Jim K. famous book... just before the inlet valves both heads can be enlarged to 37 (between valve and valve seat) and 39 mm (1) (valve seat). Just before the valve guide a 1600 head can or should (2) be enlarged to 34 mm, the 1750 head to 36 mm.

Jim K. advises to enlarge the intake manifold to 37 mm for the 1600 head and 40 mm for the 1750 head.

On the exhaust side, there are no differences.

(1): For a 2000 head this dimension is (only) 39,5 mm.
(2): The numbers indicated by Jim K. can be read in two ways: as in "should" (for ideal performance) or as in "this is the maximum possible", that's not clear to me.
 

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Nice work indeed. So from a rotating/reciprocating perspective, this is basically a 1750 but with a shorter rod/stroke ratio?
 

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I think what you are doing is great and probably what I'd do if I still had my 750F. And talk about class, I mean what car has such an elegant petcock on the side of the block! It was things like that made me love Alfas even more.
 

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I am so happy that you and your wife enjoy driving a car from a simpler time. Most importantly a car that has a built in theft deterant...... a clutch pedal. 🤯🤣🤣👍
 

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Discussion Starter · #29 ·
Thanks everyone for your comments. I suppose that what I am trying to build is just a 1750 with a shorter block. As Ipalmer pointed out, I will end up with a 1750 with a less desirable rod length/stroke ratio, but it will fit under my hood. Everything is a tradeoff.

Thanks, Koenraad for the port dimensions. I was not aware of this book and will be interested to see how my port dimensions compare. Interesting that the dimensions are different for the 1600 and 1750, but I wonder whether that is due to casting differences or just an adjustment for larger displacement?

Rob
 

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Thanks, Koenraad for the port dimensions. I was not aware of this book and will be interested to see how my port dimensions compare. Interesting that the dimensions are different for the 1600 and 1750, but I wonder whether that is due to casting differences or just an adjustment for larger displacement?
It was Domenico Chirico, a long time Alfa engineer, who said in his book that the 1750 engine uses the same head as the 1600, so casting wise, I think they are the same.

The combustion chamber will probably have a trimmed edge to adapt the bigger bore.
 

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Discussion Starter · #32 ·
I will have to get my head down off the shelf and measure the ports to see how well they correspond to Jim K's book. I will also have to get a copy of the book.

I don't know if anyone noticed, but the blue Abnormale we discussed earlier in this thread sold for $80k on Bring a Trailer ($84k including commission). That makes me feel a little better about all the work I am putting in.
 
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