ALFAGTV6.COM

Hi Guys!

I´m a bit curious, what are the gains/losses of lightening the flywheel and crank. (The car is my GTV6 3.0 QV)

I realise it all gets lighter and that will give some results. But if it is such a gain, howcome it isn´t done from factory?

If you have the crank and flywheel loose, how much work is it and what does it cost to lighten/ballance crank and flywheeel? How much is just ballancing?

I´m a n00b at this, so treat me nice

Cheers Seb

Hi Seb,
Here's my thought on the subject:
Acceleration times moment of inertia equals torque. For a given torque, if you reduce moment of inertia, the acceleration increases. By lightening the crank, you reduce moment of inertia. So you get better acceleration. But the same applies to deceleration. So i guess the factory came up with a compromise that runs smoothly in all rpm ranges without stalling. Maybe someone with practical experience on this could supplement.

When it comes to balancing, a friend of mine here in Norway got it done on his engine. As you know, Norway is a country where all good/fun things are taxed and priced beyond belief. It was between 3000-4000 Norske kroner for a good balancing job, i think. In Sweden you probably could get away with a little bit less.

Note that something about the V6 geometry makes balancing of these engines more difficult than on straight 4's. So you need to find a place where they actually know what they are doing. Otherwise you could end up with a poor result.

When i had my engine apart, i considered the balancing myself. But a very experienced mechanic i used on the valve seat machining suggested that there are plenty of better ways i could get rid of my escudos. So i let it be as original. Balanced rods and pistons though.

I make up a lightweight clutch for my milano. (look for lightweight clutch on alfabb) . The difference in response and acceleration was quite dramatic. You could probably reduce the stock clutch flywheel weight quite a bit. Its simpler to balance too.
-Tom P.