I have a cc306 cam and was wondering if it would be practical to have 1.7 rockers with this cam. If it is what would i need to change valve train wise to make it reliable and run good. I have a set of AFR 190cc heads and lots of bolt ons including LT headers.

 

Good question, I woul dhate for you to have piston to valve clearance. Why dont you clay it first?.

 

I was wondering the same thing. I was thinking the lift might clear, but wouldnt with a custom grind cam.

 

and what about valvetrain stuff like springs and retainers??

 

has anyone done this? I'm runnin 1.6's and am also curios if 1.7's would work

 

bump

come someone try it and tell us!!!

 

Hell I'll do it. I really don't want my LE2 heads being destroyed when my Ferra valves smash into my pistons, but someone needs to know. If no one else answeres this before next month, i will buy 1.7rrs instead of 1.6 rrs and i will stick them on and see what happens.

 

I have heard of guys running over .600 lift without problems the exhaust will be .612 lift.
Good luck

 

Obviously you don't want to go with a ton of lift if your heads don't support it.
.578/.612 lift is a pretty decent amount w/1.7:1 rockers. Get the heads flowed first, then pick what rockers you want, IMO.

If you're going to use the stock pistons, you'll probably need them fly-cut to run that much lift.

Mike

 

what do you mean by the fly-cut?

 

considering valve lift is not what gets you into trouble its the duration of the cam although lingenfelter does say that the stock motor can handle .600 lift they dont specify with what duration..that cam is at 230/244 @.050 510/540 you will see .541/.571 w/1.6s and roughly .603/.633 w/1.7s personally i dont see it worth the hassle of 1.7s just get a custom cam with those specs in it,besides when you combine that type of valve lift with that duration you may have enough clearence with the "clay method"but at RPM you will have rod/piston streatch and may contact a piston.
without having the pistons fly-cut i would stay under .600 lift with that type of duration,i would rather be safe than sorry...

 

You have to be careful the 1.7 rockers may open the valves to quick for the piston down stroke you should to clay up a piston and check the complete piston cycle. The reason people use higher ratio rockers is not just for increased vale lift, but to open typically the intake valve quicker for better throttle response. I would suggest using the 1.6 rockers with that cam.
I would ask a engine shop that has build a few high performance LT1 motors first before using them.

 

You have to be careful the 1.7 rockers may open the valves to quick for the piston down stroke you should to clay up a piston and check the complete piston cycle. The reason people use higher ratio rockers is not just for increased vale lift, but to open typically the intake valve quicker for better throttle response. I would suggest using the 1.6 rockers with that cam.
I would ask a engine shop that has build a few high performance LT1 motors first before using them.

 

If i were to use 1.6 Pro mag what should i change in my valvetrain i just want to do this right. Is there any significant gain between 1.5 Pro mag and 1.6 pro mag? I have 1.5 Pro mag installade because i was lazzy and didn't get valvetrain stuff. Now i want to know what valvetrain stuff to get so i can squeeze every bit of HP from my setup.

 

i would go with 1.6's to get the lift up above .550. What needs to be changed really depends on what you have now. Mainly just your valvesprings.