More NA power

[tgroth]

Short of supercharging, turbo-ing, or dropping in an M3 engine, is their anyway that the M42 could make more power than 140hp? I flipped through "Unbeatable BMW" at BMW of San Diego, and in the chapter about the 318 touring car, there was mention of an S42 engine capable of 280hp. While I realise that this probably wasn't a daily driver engine, are their any internal NA upgrades for the M42? Lighter rods? Stroker kits? Higher compression pistons?

[Ralliart]

The obvious intake, chip, and exhaust. Look into a cam from bmpd. You could probably do some porting to get some better flow also.

I would really like to know how well those cams work.

[tgroth]

True, I could do all of that, but has anyone actually upgraded the internals of the engine? I know eventually I'm going to get a Supersprint exhaust, hi-performance ignition wires, a chip, and maybe Redline Diff fluid, but I've heard that an intake does only harm to the M42/44 because the AFM flap sensor of the car does not realize that the car is receiving more air, and thus, it runs a dangerous lean mixture. I've noticed that Korman sells Mahle rods for the M42 that can be from 8% to 25% lighter. Can anyone estimate how much of a difference those would make?

[pbuchholz66]

I am planning on pulling the head on my ti and doing a full race port and larger valves (piston permitting) The stock short block should hold up well. If you do any internal mods let me know some day I might get into the short block too.

[tgroth]

Yeah, if I ever get the $$$, I would love to do some NA mods to my M42 engine, to get as much, if not more hp than the SCing it. Anyone ever put a split second HFM kit on their TI to replace the dated AFM flap valve system? I've heard that with the S14 M3 engine, 20-30 hp is easily reached with the HFM set-up.