Valve lash on new head

kipo

kipo

King of swag
Joined
May 27, 2008
Messages
707
What's the valve lash supposed to be on a cr head... on a vp truck???
My brother stopped by last night and was wanting to set the valves on his truck and we noticed the .10 and .26 sticker on his valve cover. His engine # was what I used to buy my new CR head that I put on my truck. So after the cam seizure we are picking through everything with a fine tooth comb. Found some debris in the oil passages in the rockers and some trunion wear but it wasn't very bad. We used Rotella and a bottle of ZDDP when we started it but only got 50 miles out of it before it seized.
Could the lash have been too tight causing the bent pushrods and therefore seizing the cam?
Thanks, Kip.
 
Search on the 6.7l forum here. Someone posted the new spec and reasoning for the 6.7l engines.
 
I searched before I posted and only come up with "the valve stays closed longer to transfer heat from the valve to the seat". I'm assuming that's for dropped seat issues? Cam profiles are the same on CR and VP 5.9?
Just trying to cover all angles before we fire it up again.

Thanks.
 
.010 and .020 are factory vp and 12v settings I have always set mine a little tighter @ .008 and.018 on all of my trucks and never had a problem.

Jake
 
Bodie: piston to valve contact was not evident but spray pattern was odd. not real definate but that could have been due to such low miles.

Smokem: This is a hamilton big stick cam.

We got it fired up tonight and it still seemed like something was off. We put the Mach 1.6's in and it seemed a lot smoother but some of the rockers were not oiling as much as i would like and motor seemed to be a little off balance. Rockers were completely dissasembled and slightly polished to remove some of the galling and all were well within spec. All passages were cleaned, inspected and installed after being dipped in oil. I even made a pre-luber (old oil pump with gear grinded off and nut welded on) and hit it a few times prior to starting.

We set the valves at .10 & .24 and all but one of the set screws were in the same spot. We made damb sure all push rods were seated in the cr tappets too. The set screws are pretty much flush with the lock nut but we're thinking that's due to the .20 over gasket and new head.
Should i go back to a stock thickness gasket??? What affects would the big gasket and tall head have other than lowering compression??

Thanks , Kip.
 
Last edited:
cummins spec is .006 to .015 intake and .015 to .030 exhaust on a vp truck

i set my truck to .006 and .015, much quieter than .010 and .020
 
i'm trying to keep away from them being real tight right now until we get a couple hundred miles on it.
 
You must log in or register to reply here.
Back
Top