well let start off with this isnt the first motor i have builted i have done two. stock 350 and a 383 stroker. now when my oil pump went out on my 350 lt1 i wanted to do more than just replace the oil pump. i put a high volume oil pump in, deep sump pan, 1.6 roller rockers, harded push rods, had the heads shaved .10, and a bigger cam comp cam 280 XFI cam #07-467-8

Duration Advertised: 280° Intake / 288° Exhaust
Duration @ .050'' Lift: 230° Intake / 236° Exhaust
Valve Lift w/1.6 Rockers: .576'' Intake / .570'' Exhaust
Lobe Separation Angle: 113°

doing the valve lash and "bing" piston hit valve
now what should i do
change cam?
rockers?
different size push rods?
i never had this problem
so some imput would be nice

 

Lots of people have ran this cam on stock motors without issue, even some as high as .615 lift. If the motor was rebuilt was the block decked, what head gaskets ? Shaving a head .100 is alot, hopefully you ment .010. Coil bind ? More info will be helpful.

 

have you changed the cam timing?

 

i ment .010 sorry forgot the .0 and the block is untouch with stock piston. its got new comp cam valve springs and i did not change the cam time

 

Oops! You know you have too much lift, so best to start checking clearances with the 1.5 rockers instead.
Back to kindergarten, you get to play with clay again: Century Performance Center, Inc. :: Checking and Setting Piston-to-Valve Clearance

 

Then we must question the proceedure of valve adjustment, what method do you use ? Also what ratio rocker are you using, those cam specs are for a 1.6. What valve spring combo do you have ? The common GM 847 cam has .595 lift with a 1.6 and is widely used.

 

i am running 1.6 roller rockers

howards cams valve springs
Valve Spring, Single, 1.250 in. Outside Diameter, 411 lbs./in. Rate, 1.160 in. Coil Bind Height, Set of 16

i use the methon in the haynes repair manual page 2c-4 do set my rockers

 

The only Howards spring I saw with those specs is the 98214 and if set up correctly are only rated for .500 lift, you have .576. Looks to be a stock replacement. I'd say you need new valve springs. That cam was made to run the 26918 beehives which is what's recommended. You'll also need the 787-16 retainer and 648 lock.

 

even if wrong the springs arent going to change the valve hitting the piston while turning over by hand.
94z, is this how you adusted the lash..?

4th Gen LT1 F-body Tech Articles

 

He has coil bind, .576 lift on a .500 lift spring. I guess we need to know who spec'd the springs for his cam. Maybe he threw the cam in without new springs. People run that cam everyday. The only other thing is like you said, the cam timing is off.