m40 318i vs m42 318is

[chirayath21]

hey guys,
was wondering what the main differences between the two blocks in the title are.
I know that the m42 is 16v, but thats about it.
Are all the other compnents the same such as the breathing gear, as i am looking at induction kits for a 318i, and im wondering if i can use parts advertised for the IS?

cheers!

[SwirlyE30]

No mate the intake and stuf fis differnt. The airbox looks the same shape off the top of my head, but the pipe going to the AFM from the Throttle body is differnt and the AFM probbably is as well. Not sure you could get away with using bits meant for the IS!

[Dan318-is]

m42 was based on the m40 block. thats the only similarity

M42 has lightened pistons and balanced forged crank and a heavier flywheel than m40, also has a adjsutable cam sprocket completely different head and different exhaust manifold. add this to the air flow meter comment about, i dont really know if the bits are compatable lol