blackey

iTrader: (1)

What would be the largest cam for a 50% roadrace, 50% track engine. This is not a daily driver. Ideally it would last 60 hours between valve changes and 6K miles while reving to 6500. Is it the lift that kills the valvetrain or the shape of the lobe. AKA if you had a mild lobe with .600" of lift would this last?

I'm currently using the ASA cam (entire engine actually), and would like a bit more without getting carried away.

Assume al the supporting mods are done.

SouthFL.02.SS

I don't think it's the lift that kills the valvetrain- moreso the aggressiveness of the lobe itself is what does things in. But! Since you're going to have such frequent parts refresh cycles I'd say go for a proven LG G5X3 (Compe XER lobe) and not worry about valvetrain wear if you're setting up the valvetrain well (invest in some nice lifters).

Otherwise, if you wish to stay conservative, something on a Comp XE grind, within the range of 228 thru 234 duration, .57ish lift, on a 110 thru 112 lsa will suit you fine.

SouthFL.02.SS

Or, for a mildly decent upgrade, you could always upgrade your LS6 springs with some Comp 918's and put some Crane 1.89 Roller Rockers on there and stay with the ASA cam.
http://www.vincihighperformance.com/...RTSPARENT.HTML

Phoenix 5.7

iTrader: (7)

either the ASA, or give LG Motorsports. Lou has years of experience in road racing, and, of the sponsors i know of, has the most knowledge of actual road racing when it comes to engines

blackey

iTrader: (1)

I've thought about the keeping the ASA cam and going with rockers, but I've heard so many issues with them, aka heavy, valve float, etc...

So how about something like Patrick G's cam? Would it last 60 hrs at 4500-6500 rpm?

SouthFL.02.SS

Patrick G's XER lobed cam or his LSK lobed cam? I think as long as you have the right valvespring and a decent lifter in there, properly setup, you could do just about anything. PM him and ask him about his entire valvetrain setup. Also, if I recall correctly, he has flycut pistons to accomodate the high lift of his cam grind (at least, this was the case a year ago).

As for the rockers, there are some out there with valve float issues, there are some without. I'd do a little more research into the matter (and try calling Vinci) before giving up on the Crane rockers, as everyone on the board is quick to point out that aftermarket rockers (without knowing which ones) are prone to valvetrain problems at high rpm.