Jimgreek, have to agree there. 7000 is plenty enough and realistic for fast road and some track and probably reasonably reliable, and 6500-7000 is what I am looking at with this spare engine. As you say, I find it hard to visualise how the 12v 2.5 or 3.0 heads could breathe past 8000rpm, maybe you would have to seriously port the heads, with huge valves and cam duration, and run some sort of open trumpet intake, with a custom plenum and scoop??? The lack of valves would be a problem!. having said that these engines have been up to that sort of rpm, as 80's touring cars proved, but they broke a lot!
But seriously, I think it could be done with a 24Valve, afterall F1 are only allowed 4 valves per cylinder!!
I would love to have the cash to build a light weight absolute screamer 3.0 24v turbo, 9000 rpm!. Imagine that!, into late eighties williams and benneton territory
![Cool 8)](./images/smilies/icon_cool.gif)