Alfa Romeo Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
561 Posts
Discussion Starter #1
I have a few questions here. To start: I am going to list all variations of engine capacities of the classic Alfa twin cam that I know. Then ask the questions for people to have input. I have added a couple of other reasonably well known unique engine capacities just for the hell of it. I realise this is by no means every combination that can or has been achieved with this engine. But then, this is the point of this exercise. With a few questions answered, I can formulate a spreadsheet of all reasonably achievable engine capacities of the TC, and how to achieve it.

Format: Bore x stroke (mm) = capacity (cc) [model, notes]

74 x 75 = 1290 [all standard 1300 engines]
78 x 67.5 = 1290 [GTA Juniors]
80 x 67.5 = 1357 [Neuvo 1300 engine]
86 x 67.5 = 1568 [GTASA]
78 x 82 = 1567 [all standard 1600 engines]
80 x 88.5 = 1779 [all standard 1750, or 1800 Alfetta engines]
84 x 88.5 = 1962 [all standard 105 and 116 engines, 75 and early 155 T-S]
84.5 x 88.5 = 1985 [GTAm]
84 x 90 = 1995 [Late 155 2.0 T-S, all 2.0 164 T-S]
84 x 80 = 1773 [Alfa 155 1.8 T-S]
80 x 87 = 1749 [Alfa 155 1.7 T-S]

1. Have I got any of the above dimensions wrong?

2. Any additions?

3. What was the purpose of the 1.7 155 engine? (also: I am not quite sure on the dimensions of this engine…. )

4. Are there any significant differences between the 75 and the 155 cranks? E.g: nose of crank…

5. Do the 1.7 and 1.8 155 T-S engines use the same bore pitch of 2.0? (Would make sense)

6. I have heard a couple of people on this site refer to a 2.1 engine. I also have heard that there were a few engines using this capacity (legally and illegally) in Australia for racing. How was this capacity achieved?
 

·
Registered
Joined
·
757 Posts
Hi Clayton,
1) 1357cc is the Giulietta 1.3 (80's)
3) 155 1.7 = 83.4x80 = 1749cc. This model did not have vvt and was only sold in certain markets where there was a road tax and insurance rate discount because it was under the 1800cc class. A specific market targeted back then was Portugal - I know because I used to translate the official factory marketing literature.
6) The 2.1 engine (more precisely 2.06) was the 2liter with 87mm pistons. Liners can be bored out to this size and there was an actual Spider version available as a new car in Germany back around 1972 or thereabouts. With minimal other mods (jets etc)it had a real (dyno) 150hp, tested by the respected AMS carmag.
Jim K.
 

·
Registered
Joined
·
268 Posts
for the 2.1 cosworth pistons were (are) still available, though expensive. Then have the bores honed and there you go. lot's of lowdown torque in the two 2.1s I had, one in a Super, the other in a Berlina.
Don't remember the head gasket used though...
Jim, there was also a company in Germany at the time who built 2.1 engines in Supers new at that time. I have an old Quattroruote with a lyrical road test of one.
Somewhere, so don't go asking.....
 

·
Registered
Joined
·
2,222 Posts
86 x 67.5 = 1568 [GTASA]
78 x 82 = 1567 [all standard 1600 engines]
86 x 67.5 = 1600F2 engine mounted also in some GTA's

GTA-SA has the same bore and stroke as the regular 1600, ie. 78 x 82, even though most printed material suggests otherwise.

I have seen 3 of these engines (at the late Angelo Chiapperini's shop) and acutally measured one of them after it was pointed out to me that they had standard bore and stroke. Actually makes sense when you think about what effect you are trying to achieve w/ supercharging ... certainly not high rpm.
 

·
Registered
Joined
·
2,222 Posts
Actually 1600F2 should be 86 x 68.5 (monobloc) for 1592cc total displacement

Some others:

83.4 x 68.5 1497cc 1500 marino (monobloc)
86 x 82 1905cc GTA 1900
86 x 88.5 2056cc 2000sp (monobloc - 1 built)
1698cc IMSA engine 81.2? x 78?
 

·
Registered
Joined
·
561 Posts
Discussion Starter #6
Thanks for the input guys. Man, those liners with 87mm slugs must be thin down the bottom!

Any info on the compatibility of 155/164 t-S cranks into the earlier type of engine? From what I know about these (not very much!), the oil pump is a different arrangement. Therefore it is conceivable that the nose is different.

The 1.7 (a true 1750!!!) has a sweet bore/stroke ratio. If you had a reason, you could turn that into a really nice engine. Probably rare as rockin' horse poo though!
 
1 - 6 of 6 Posts
Top