Difference between M54b30 &b25

[LsBeema 464]

Bemma brus...

Can some please tell me the differences between these 2 engines...?

Crank, rods even pistons are different. B30 pistons are completely different in shape then ones of B25. B30 has a different Intake cam. Exhaust cams are identical with both B25 and B30. Obviously B30 has a bigger and more flowing intake manifold with a bigger DISA valve. Head with valves and cams ledges are the same.....

Can someone confirm this...

Sweet

Thanks

 

Edited July 16, 2022 by LsBeema

[Vass 832]

Yeah looks about right.

Heads are identical apart from the intake cam. Currently using a head from a b25 for my b30 rebuild. The flap on the b30 DISA is bigger so the manifold must be different as well.

Haven't pulled the bottom end of the b25 apart just yet so can't compare, but safe to assume that at a minimum the crank will be different. 

[LsBeema 464]

45 minutes ago, Vass said:

Yeah looks about right.

Heads are identical apart from the intake cam. Currently using a head from a b25 for my b30 rebuild. The flap on the b30 DISA is bigger so the manifold must be different as well.

Haven't pulled the bottom end of the b25 apart just yet so can't compare, but safe to assume that at a minimum the crank will be different. 

Thanks Man

[Vass 832]

Don't know what mission you're undertaking but might be worth noting that there were also a few things that changed around 09/2002 for both b25 and b30. The valve cover, coils and associated wiring changed as well as a difference in harmonic balancers. The main auxiliary side is the same I believe but on the AC side the number or ribs changed so the belts aren't interchangeable.

Worth checking out if you're swapping engines that are opposite sides of that date.