Ok guys let’s hear it s8 heads/cams

[mi021le]

Alright guys I wanna hear any knowledge you have on this topic and hopefully we can make a guide if it’s worth it. I’ve heard from some people it’s not worth it yet others say it is. I know the s8 heads are different them the rs6. The rs6 heads have a code but all the s8 heads I’ve seen are all just serial numbered and don’t have code number. I sent off the s8 valves to see if they could be just replaced with a ferrea rs6 kit and they said the rs6 valves are 8mm longer then s8.

Now which s8/s6 cams are people using? Intake and exhaust or just one. I’ve heard Tim used some on his rs6 build but don’t know much more then that. I’ve seen s8 dyno graphs a d it looks like you get more above 5500 rpms.

Again any info would be appreciated. Thank you

[nubcake]

Exhaust cams are the same.
Intake cams are different.

RS6 exhaust valves are smaller & sodim-filled for better cooling.
Intake valves should be the same, but I didn't verify part numbers. 90% sure Ferrea messed something up.

Heads are therefore different as well (exhaust valve size). But they will bolt on.


Bottom line is:
You're doing a big turbo setup with good intake/exhaust flow - go for S8.
You're leaving RS6 intake & turbo hot sides - don't bother.

[RS8]

There is also more overlap on S8 cams.


But then there are different castings, I now use A8 cylinder head with S8 camshafts, but these cylinder heads lack water outlet at the front edge under the intake so the shiny aluminum pipe that sits on rs6 is missing and it is this pipe that also supplies the water to turbo, so had to make a separate outlet in the rear pipe for the water, then it was also necessary to grind away aluminum behind the cylinder head so that the RS6 pipe that goes behind and down to the water oil cooler in the front would fit.
So it is important to buy the right S8 cylinder head to avoid rebuilding too much.

I have Supertech big valves and Supertech valve springs fitted in this A8/S8 head.

But I have not tested back and forth, so I can not say what the difference was with S8 camshafts.
I was driving with only A8 intake camshafts before.