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      09-26-2013, 05:13 AM   #18
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Originally Posted by mkoesel View Post
What is the bore center dimension of the S55?

I am having a very hard time believing that they've increased the bore center only to achieve essentially no displacement increase. Sure, the stroke decrease is great, but they've avoided it for years with the S50->S52->S54 even as RPMs were pushed higher and piston speeds went up and up. Why the change now?

If we really do get a new longer block, then this is arguably the single biggest piece of engine news from BMW since they reintroduced turbocharging seven years ago. It would mean a square bore 89.6 x 89.6 3.4L engine is possible - the first time we can (safely, reliably) go over 3.2L with a BMW I6 since they retired the "Big Six" decades ago. And without resorting to an iron block as every OEM I6 engine above 3L from BMW has used.

And if we don't get a new bore spacing, I am at a complete loss for words as far as the incredible 1.4mm between cylinders.
Good points.

I hope that what we see is the basis of what happened with the E36 engine. First a 3l then a later version with 3,2l. This engine leaves (possibly) room for displacement upgrades down the road and/or CSL type versions with larger volume than the std. engine...

On a NA engine they wanted the longest stroke possible to gain some torque for driveability, hence why the old engines had a fairly long stroke. On the S55 the FI takes care of the torque deficit present in a short stroke engine. You can have your cake and eat it Both short stroke and high torque

Last edited by Boss330; 09-26-2013 at 05:39 AM..