[CrispDust]

Whats the difference between the 3.2 and 3.0 V6. Presumably its bored out with slight increase in torques and horses, but similar otherwise?

 

[David C]

Longer stroke too.
So crank & rods also different.

 

[badgers_nadgers]

Longer stroke too.
So crank & rods also different.

Really? I thought it was just a longer stroke. Interesting.

 

[David C]

Can't remember and can't be arsed to look.
The bore may be the same, but the pistons are different anyway.

 

[robcarrera32]

just longer stroke - from internet research. Makes sense for most capacity increases, cheaper to add stroke with new pistons and/or rods rather than machine bores. Sometimes can fit new liners, but would need to be pre-engineered of course.

Checked this to confirm the F/L 166 with 3.2 engine was still the Busso unit, not the GM unit. What chance the GM unit would be the same bore?

 

[Pomeo]

Whats the difference between the 3.2 and 3.0 V6. Presumably its bored out with slight increase in torques and horses, but similar otherwise?

Different camshafts ...It has a different camlock kit.

Pomeo

 

[badgers_nadgers]

Different camshafts ...It has a different camlock kit.

Pomeo

Isn't it just the inlet camshaft that's different?

 

[Pomeo]

Isn't it just the inlet camshaft that's different?

don't know badge...just that the kit is different.

If that's the case why not just do like all the software companies do and just do an upgrade...ie the inet locks.

Pomeo

 

[fetta head]

whats the difference in real terms drivabilty performance etc?

 

[alan Q4+33]

3.2 has longer stroke and shorter rods, so that the pistons dont hit the heads. Engine block is the same.


3.0 - bore 93.00mm x stroke 72.60mm
3.2 - bore 93.00mm x stroke 78.00mm

3.2 has different inlet cams

All in all 3.2 is a little more torquey engine and powerfull ofcourse.


GM based engine is totaly different: bore × stroke 87.50mm × 88.00mm

 

[robcarrera32]

3.2 has longer stroke and shorter rods, so that the pistons dont hit the heads. Engine block is the same.


3.0 - bore 93.00mm x stroke 72.60mm
3.2 - bore 93.00mm x stroke 78.00mm

3.2 has different inlet cams

All in all 3.2 is a little more torquey engine and powerfull ofcourse.


GM based engine is totaly different: bore × stroke 87.50mm × 88.00mm

So Alfa engines should rev higher than GM unit due to being over-square and short stroke. The 3.2 unit is even shorter stroke so could rev even higher that 3.0 as piston speeds will be lower?

 

[alan Q4+33]

3.0 revs the most
3.2 piston speed is bigger and that can be an issue, and also the angle of the rod when the crank is on quarter of rotation is bigger because rod is shorter and the crank has bigger stroke (not good and puts much more stress on components)

Sketch made in paint for understanding:

 

[robcarrera32]

Nice picture Alan, thanks. Did not realise 3.2 had different crank, I thought capacity increase was just the shorter conrods giving less stroke, therefore more combustion volume. Guess I was being too simplistic, although is does seems expensive to add new crank for 200 cc.

 

[David C]

Nice picture Alan, thanks. Did not realise 3.2 had different crank, I thought capacity increase was just the shorter conrods giving less stroke, therefore more combustion volume. Guess I was being too simplistic, although is does seems expensive to add new crank for 200 cc.

Changing rod length does not change stroke or capacity.
Engine capacity is the swept volume of the piston, not the size of the combustion chamber.

To change from 3.0 to 3.2 would mean new: crank, rods, pistons+liners.
There is no point doing it as an upgrade, going to 3.5 would probably cost less as it still uses the 3.0 crank.

 

[robcarrera32]

Changing rod length does not change stroke or capacity.
Engine capacity is the swept volume of the piston, not the size of the combustion chamber.

To change from 3.0 to 3.2 would mean new: crank, rods, pistons+liners.
There is no point doing it as an upgrade, going to 3.5 would probably cost less as it still uses the 3.0 crank.

Thanks DavidC
Must re-visit my engine theory, "how stuff works" website perhaps.
If I were in the market, I would look at AH upgrade to 3.7 or 3.8.:wow: with Q2 of course.

 

[CrispDust]

I only asked as am considering a GTV and don't if to go for f/l 3.2 or not ( i'm not keen on the f/l GTV front though)
Just wondered if there was a real difference in the engines performance etc
However in summary 3.2 the crank swept diameter must be longer and con rod shorter to allow the greater stroke over 3.0 if bore is the same.
What is 2.5? Same bore and shoter stroke or different bore/stroke?

 

[alan Q4+33]

2.5: Bore × stroke 88.00mm × 68.30mm

I will say go for the 3.0 and for the money that you will have left, buy a q2 diff an go for the remap (maybe exhaust and intake too, ofcourse before remap)
Then you will have a great reliable alfa that's just as quick as the 3.2

 

[Pomeo]

3.0 revs the most
3.2 piston speed is bigger and that can be an issue, and also the angle of the rod when the crank is on quarter of rotation is bigger because rod is shorter and the crank has bigger stroke (not good and puts much more stress on components)

Sketch made in paint for understanding:

wow alan ..a flashback to 5th year at high school over 40 years ago.:wow:

Pomeo