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Discussion Starter #1 (Edited)
Hi

I’ve found an unstamped NOS Alfetta block that I am possibly going to use in my 105 Sprint GT.

I’ve been told it’s a 1750/1800 but from the info I’ve found online I’m not completely sure as the symbol on one end seems to denote 1750 but the other 1600 please can anyone help clarify exactly what model of block it is?

Many thanks in advance Pete
 

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Quite easy.
Forget the marks.

It's a late block because it already has 7mm studs for the water passage.

Measure center bore holes: If 1/2 and 3/4 are equal to 2/3, it's a 2000 (all center bore figures =93mm)

Regarding block height ABOVE the 7mm studs it's not a 1600. 1750/1800 and 2000 blocks share same height.

Center bores are the way to verify it's a 2000 or not.

Do you have the front chain cover to that block, too? Post pictures please.
 

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@hunttheshunt

Thanks for your reply it much appreciated I’ll get measuring!

Unfortunately I don’t have the front chain cover it’s on my need to find parts list along with a crank etc.

Regards Pete
 

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No side oil filter in the block. Not a 1750, must be a 2liter
Wrong conclusion.
LATE blocks (=7mm studs), also on 1800's, do have oil filter flange in front cover as well.

1750 called blocks are from 105/115's.
1800 called blocks are from 116/162's.

That shown block definitely is not from a 105/115. No thread for oil pressure warning light switch.
 

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Wrong conclusion.
LATE blocks (=7mm studs), also on 1800's, do have oil filter flange in front cover as well.

1750 called blocks are from 105/115's.
1800 called blocks are from 116/162's.

That shown block definitely is not from a 105/115. No thread for oil pressure warning light switch.
Correct. Alfa made smaller capacity engines with later style front cover oil filters deep into the 80’s. Think 1,6 and 1,8 75’s as examples. Just not sold in the States.
 

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Discussion Starter #7
@hunttheshunt

Following your help I have measured the bore centres and have 1/2 and 3/4 at 90mm and 2/3 different at 93mm so I can assume it’s a 1750/1800 block.

Please correct me if I’m wrong?

Thanks again for all your help!

Regards Pete
 

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I can measure the OD of a 2000 liner to give you that dimension (fitting into the holes in the block). A 1750/1800 would be smaller OD.
Andrew
 

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@hunttheshunt

Following your help I have measured the bore centres and have 1/2 and 3/4 at 90mm and 2/3 different at 93mm so I can assume it’s a 1750/1800 block.

Please correct me if I’m wrong?

Thanks again for all your help!

Regards Pete
You're partly right BUT it's only proven now that it's NOT a 2000 block for sure. It still could be a 1600. Measure now the height above the upper/outer 7mm bolt near the water passage up to top of the block.
 

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Then you definitely have a 1600 block. Without any doubts. One of your first pictures did mislead me a little bit as the height above the stud didn' t look like for a 1600, but with 2,5cm it's definitely a 1600.

1800/2000 would measure 3,5cm there.

But: 80mm liners from a 1750/1800 will fit into that block when shortened. This would give you 1648cc against 1570cc std from 1600 with 78mm pistons. Cyl. head from 1750/1800 perfectly fits on a 1600 block, too.
 

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Or if you want the longer stroke, get somebody to make an alloy plate to sit on top of the block ... although the head holding studs may then be too short ...

If this is to be a race engine, then the alloy plate should be designed to locate the top of the liners, which surely will make the block close to as strong as a mono-liner block.
Pete
 
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