whats the safe max rpm a FI application a 4.100 crank can handle

 

Depends a little on power level and the quality of the crank itself. If it is a 4340 center counterweighted crank with properly matched components it should be fine at 8000, if the right parts are used and the supporting oiling is in place 9000 would be achievable.

Kurt

 

What motor do you intend on putting that in? What length rods? NA?

 

7500rpm with 4.1 stroke will be around 5125 fps piston speed
with quality bearings,assembly and premium parts it should have no problem spinning that.

 

yes, what he said

 

its a FI application vortech ls2 block

can i do a 6.125 with a 4.1 stroke in a ls2 block

what im trying to do is keep the stock bore and add some stroke in order to add tq but also rev her to atleast 7500