Quote:
Originally Posted by Boss330
The S54 certainly isn't a run of the mill engine. Not even remotely so! It's a fantastic engine and this was not the point at all. Point is that it is a development based on a BMW AG engine, just like the S55...
You might want to reconsider your impression that the S70/2 engine use S50B30 heads/cams/vanos/pistons/rods though...
First of all, a V engine needs to run two mirror shaped heads. At best you could use a S50B30 head on the right hand bank of a V12, but it would not work on the left hand side for obvious reasons...  Same with cams, VANOS and cam drive obviously.
Also, since the S50-S54 use a cast iron block and the S70/2 use a alloy block with Nicasil liners, I suspect special pistons was made for the S70/2. Similar in design most likely, but probably not the same part number (unless you have info otherwise?). And with a I6 engine having just one con rod per crank journal and a V12 having two, I suspect that con rods also are different...
Not to take anything away from the S54, since that is a "old" engine. But the Porsche 997 GT3 RS 4.0 and 991 GT3 engine also makes more tq/liter than the S54.
As regards piston speeds, it sure has a really high piston speed, but not quite as high as the 2006 F1 engines that revved to 20.000rpm... It's also not the highest piston speed seen in production engines...
1. Audi RS4 (2005)
2. Audi R8 V10
3. Honda S2000 (F20C1 engine)
4. Lamborghini Gallardo
5. Acura Integra Type R (B18C5 engine)
6. BMW S54
Again, this is not to take anything away from the awesomeness of the S54, just discussing some points  |
Perhaps I should have more accurately said the S50B30 is half of an S70/2, instead of the S70/2 is two S50B30s. Because, yes the other head is indeed the mirror (a fact I'm well aware of, sadly, having just refreshed the top end of my S62 this summer (an engine that really is just a worked over M62)). My point was, jokingly, that the S54 has more in common with the McLaren F1 engine than the M50-- which I believe you agree with, technicalities aside.
Okay, 6th highest piston speed of all engines of all time, and slower than one year of Formula 1. I guess my info is a bit out of date. Still, relevantly to the discussion at hand: faster than the S65/S85. Higher specific output than the S65/S85.
My point was that it wasn't a worked over M50