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[gbh]

I was just wondering really when looking at the 3lt and 3.2lt engines on the 3lt there is a lot of extra bits in the engine.Were they just put somewhere else on the latter and could you modify the 3lt with 3.2 parts if they just improved the design.

[05omegav6]

Mostly emission control related... Early cars have ecu controlled mechanical devices, later cars 2.6/3.2 and 2001 US 3.0 have all the work done by a far more intelligent ecu, negating the need for the gubbins

[Andy H]

The 3.0 litre had a secondary air injection (SAI) pump to blow air into the exhaust manifolds during warm up to warm the catalytic converters more quickly. It doesn't usually cause any trouble (and you can remove it if you want to), The 3.2 dropped the SAI and had small catalytic converters added in front of the main cats with the intention that the small cats will warm up quickly to handle some of the emissions until the main cats were up to temperature. The 3.2 has extra Lambda sensors between the pre and main cats which sense when the pre cats stop working (and will fail the MOT) there is a fix which involves moving the sensors to after the main cats however.

The 3.0 litre has an exhaust gas recirculation (EGR) valve which opens when cruising which sends some exhaust back into the inlet manifold to modify combustion and reduce the amount of nitrous oxides (NOx) produced. The 3.2 has a reduced compression ratio to reduce NOx - unfortunately this makes the engine less efficient (so they made it 200cc bigger to compensate).

The only real improvement on the 3.2 is the stainless steel exhaust manifolds. Deleting SAI and EGR makes the engine a little bit easier to work on and the throttle is 'fly by wire' so you get cruise control as a bonus (it doesn't require a separate servo motor).

The ECU is a newer design with more sophisticated fault diagnosis but it doesn't have any magic way of reducing emissions - it can only adjust fuel/air ratio and ignition timing - the earlier one could also open the EGR.

[zirk]

And with all these bits they added or took away, they managed to screw up on economy.

The 3.0 are far better on mpg than the 3.2's.

[tunnie]

Yup, I owned a 3.0 PFL Estate for a while many moons ago, was MaxV6's old one. It was actually very good on fuel, the 3.2's are utter shite in comparison.

[biggriffin]

The perfect situation is.
3.2 bottom end, 3.2 heads skimmed,3.2 manifolds, in a 3.0L car.and a chipped ecu.

[tigers_gonads]

Has anybody ever dropped the heads of a 2.6 and fitted them to a 3.2 ?

Much difference in fuel economy of power ?

[biggriffin]

Has anybody ever dropped the heads of a 2.6 and fitted them to a 3.2 ?

Much difference in fuel economy of power ?

They are the same.

[Kevin Wood]

Has anybody ever dropped the heads of a 2.6 and fitted them to a 3.2 ?

Much difference in fuel economy of power ?

They are the same.

I'd expect the 2.6 to have smaller combustion chambers, giving a 3.2 higher compression.