BMW V8 S65

[Irace86.2.0]

Originally Posted by GrabTheWheel

If you have the budget to do an M motor swap you could pretty much do whatever you want with an LS. Here’s one that revs to 10K rpm and has 16.25:1 compression.

Oh I’m sure anything can be done with an unlimited budget on any motor. A used S65 motor and trans seems to be cheaper than a LS and trans, let alone a built LS and custom gears/box for a 10k redline.

[Tristor]

There is an S85 sitting partially assembled at my local shop along with the BE Bearings to go in it. I'm heavily considering buying it off the shop and rebuilding it for an eventual swap. I took some measurements, and it's clear you'd need to move the firewall back a few inches and fabricate a custom front subframe. I cannot imagine doing this swap in anything except for a purpose-built track car, but I will freely admit that a high-revving version of the S85 swapped in would be really quite fantastic.

The S65 is essentially a V8 version of the S85, with two less cylinders, but otherwise mostly the same. I think it is has a higher reliability version of Vanos because it removes the high pressure side in later revisions of the engine, but otherwise it's basically the same. It might fit a little better, but I didn't take measurements for it.


Given what I know and the expected cost involved, I decided a much more sensible swap would be the Synergy V8 if I wanted a high-revving V8. I think it's possible to get quite a lot more power out of the S85 or S65 than you can get out of a Synergy, but I don't believe it'd be any higher reliability, and it certainly would not be cheaper. To get into similar rev ranges (10k RPM+) reliably on the S65/S85 you need custom short stroke billet crank, bored and sleeved block, significant valvetrain work, aluminum pistons, solid lifter conversion, etc. to reduce rotating mass enough and resolve valve float tendencies.


I am not really a BMW fan, but these engines truly roar like the voice of a thousand angels with a good exhaust as is, so I can only imagine a higher-revving version. It'd definitely make a beautiful sound in this platform. Given the work required to do it and the cost, it is actually more economical to go a proven route like the Synergy V8, as surprising as that may sound.

[Irace86.2.0]

@Tristor

In the video, the S85 engine looks snug, but not bad. They mention needing to modify the transmission tunnel more than going crazy on the engine mounts. Just saying.

http://www.ft86club.com/forums/showp...62&postcount=5

[GrabTheWheel]

If you want to do something different than an LS the 1UZ swap is one of the coolest swaps I've seen on here. Since dumping so much into my swap I'm pretty much married to the car at this point and the idea of having affordable parts readily available for years to come makes me feel good.

My hope with the swap was to increase reliability and get away from boost while still making great power. If you get accustomed to the torque of a V8 for street driving it's hard not to always want it. The S65 makes good power without FI and it sounds good, I'm just not sure about the reliability part. (Not to mention the cost and difficulty of actually doing the swap)

[Irace86.2.0]

@Tristor

As I said earlier, I wasn’t interested in a swap. It was more of an exercise in possibilities, but I agree the LS is the cheaper route most likely due to support and kits available to make swaps plug n play. The S65 will be more available as used motors, so I think this could be a good option for anyone wanting something more exciting than the typical LS/2JZ. ITBs with high revs without needing to crack it open is a big deal.