I'm wondering how much boost a stock crank in a 6.0 can handle? On a previous engine that was completely stock I ran 10 lbs of boost with a whipple sc, and after some issues (none related to the crank) I built an engine that had forged pistons and an 8:1 cr and ran 15+ lbs of boost with a single turbo and no crank issues.
I currently have a stock 6.0 in the truck with just 4 lbs of boost, and the driveability is good, with very good mpg. The truck won;t see alot of track time anymore, and I'm getting ready to build the broke LQ4 with a 9.75:1 cr and run 5-6 lbs of boost around town with maybe 10-12 for the occasional track night.
Is there really a need for a high dollar forged crank at this level with race gas and meth inj?

 

Your crank, bearings, and connecting rods should be fine. What you need IMHO are new rod bolts (stock ones stretch at high rpm's), maybe forged pistons depending on how aggressive you plan to get with spark timing, and some better valve springs and pushrods. A search will yield some good brand names.

 

 

Kinda high CR for 12#'s of boost no?

 

... depends on how much timing you screw into it. Also, if race gas and meth is used that will add a bit more insurance. I will concede, however, that a cheap set of Eagle H-Beams would go along way for insurance considering the minor difference in cost of better rod bolts versus the cost of Eagle rods.

Bill

 

I personally like the I-Beam rods Richard @ WCCH sells because they are lighter than stock and come with 7/16" bolts for a great price....and they needed zero additional work before install.

 

Speaking of Richard @ WCCH, he and rex build my motor and I plan on running +20# of boost on a stock crank...They said the crank was not gonna be the weak link in my set-up and therefore going forged wasn't necessary.

 

I would only go to an aftermarket crank if you plan on increasing the stroke...because, then, you have to.

 

Rod bolts, etc were going to be arp (or eqv) on the new engine, and I won't be stroking it. with just some forged pistons and the low 8:1 cr in the previous engine it went low 12's, and we are not planning on going back there. Low 13's high 12's is sufficiently fast for what will now be a mostly street truck. (A 69 camaro in the mid 11's and a 67 camaro in low 10's high 9's as the dedicated race car are more than sufficient for breaking out the wallet on a regular basis for repairs) I'm planning on the higher cr to help with drivability and mpg as a street vehicle running just 5-6 lbs 95% of it's life. The only time it will see much higher boost is at the track with race gas and meth, and that will be limited to maybe 10-15 passes a year. Thx for the replies!

 

That CR won't be a problem at 12 psi depending on the tune and fuel delivery. I ran 12 psi with meth (no FMIC) on 10.1:1.