BMW Retires Its Legendary Straight Six Engine S54B32

[Sid 6.7]

BMW Retires Its Legendary Straight Six Engine S54B32

Fantastic engines are to car people like a fine vintage is to a wine enthusiast - not just to be used, but enjoyed, savored as some of the highest expressions of the art of their creation. But like all such things, they are fleeting. BMW's S54B32 engine, the straight-six 3.2L cast-iron motivator that powered such greats as the E46 M3, the Z3, Z3 M, Z4 M, and even the Wiesmann MF3, has now headed into retirement.

The final Z4s, built at the tail end of 2008, housed the last of the S54 straight-sixes, reports CAR. Instead, the replacement cars will feature only a 3.0L twin-turbo rated at 300hp (223kW) as the top-of-the-range model. They're sure to be fun and are most likely somewhat underrated in terms of outright horsepower, but they are unlikely to have the same character of the outgoing mill.

Singing along at its 7,900rpm power peak - just 100rpm shy of redline - the S54 was one of the most sonorous of BMW's sixes, and a worthy successor to the S50B32 of the E36 M3, itself a sonic powerhouse.

At 3.2L, the engine was a middleweight doing the fighting of a heavyweight. Rated at 343hp (252kW) in Euro-spec trim, the addition of U.S. emissions equipment bridled the engine back down to 333hp (248kW) in America.

Some of the awards the S54 earned over its roughly seven-year tenure at BMW include the International Engine of the Year Overall and Best New Engine awards in 2001, the winner of the 3-4L category from 2001-2006 and a spot on Ward's 10 Best Engines for four years running from 2002 to 2004.

Though troubled early on by some mechanical problems, most relating to the car's stratospheric redline and some sub-par contracted engine parts, the S54's cast-iron block and otherwise bulletproof construction have earned it a spot among the most praise-worthy engines of recent times.

[Sugarphreak]

That is too bad, I have a special place in my heart for inline 6's

I was pretty unhappy that Jeep replaced the inline-6 with a V6. While you can squeeze higher RPM's and more horses out of them, you loose that huge stroke and massive low end torque. For 4x4's who cares about high RPM's or max horsepower... you need that low end torque to move the truck controllably over steep grades.

I always thought it was cool that BMW kept the inline-6 because it offers such great response off the line and keep the RPM's nice and quiet for long drives.

Oh well, pretty soon all cars with be a homogeneous mix of lame designed to appeal to the statistical masses.

[kylerwho]

i have heard that the V is a cheaper design when casting the block. that is why everyone is getting rid of the inline 6. its a bummer cause the 2jz, rb26, and s54 have been some of the best power motors around.

[polaski]

That's too bad. I've always been an I-6 fan, mostly because it's the only piston engine (that, and flat/v 12) that can be perfectly balanced, rotationally and end-for-end. Other engines, sure you can balance the crank, I-4s can have opposing pistons cancelling each other's momentum, but the I-6 even has the connecting rod motions canceling themselves out. Makes for one smooooooth runner.

It's just so expensive not just because of the block, but because the longer the crankshaft the more perfectly centered and balanced it has to be to keep it from wobbling and eating bearings.

Oh my, are those individual throttle bodies I spy in that picture?

[meestersteph]

Originally Posted by polaski

That's too bad. I've always been an I-6 fan, mostly because it's the only piston engine (that, and flat/v 12) that can be perfectly balanced, rotationally and end-for-end. Other engines, sure you can balance the crank, I-4s can have opposing pistons cancelling each other's momentum, but the I-6 even has the connecting rod motions canceling themselves out. Makes for one smooooooth runner.

It's just so expensive not just because of the block, but because the longer the crankshaft the more perfectly centered and balanced it has to be to keep it from wobbling and eating bearings.

Oh my, are those individual throttle bodies I spy in that picture?

IIRC, ITBs came stock on all E46 US M3s and E36 EURO M3s :)