slowec

iTrader: (9)

I have a small base circle z06 cam.
I was told 7.45 pushrods were correct?????????
Is this correct?????

kbracing96

iTrader: (26)

No, stockers will work, but to keep the same range of travel in the hydraulic lifters, the Z06 cam is .050 smaller in diameter, so to make up for that, you need .025 longer (diff in the radius), so that would be 7.425.

slowec

iTrader: (9)

I was told by a sponser ...That I needed 7.45. I believe the 02 ls6 valve is .7 millimeters longer which comes to .275 inch difference, so I am not sure why I was told I would need 7.45's. I do know I have the 7.45 on my tool box and if they are wrong ...my install schedule is PHUCKED!!!

I have read old posts for over an hour and found people have used this cam with 7.4 , 7.425, and 7.45 pushrod lenths and they all claim it worked out fine.

How much difference could .25 make anyhow. Its not like I am running solid lifters???

kbracing96

iTrader: (26)

I can tell you this. I DID this swap and i measured the two cams myself with a digital micrometer. The 02 Z06 cam is .050 smaller. Yes, the valve on the Z06s are longer, but you have to take into consideration the rocker arm ratio, that lessens the amount of the travel back to the cam.

You can use you stockers to get it going and order some 7.425 if you want, but I ran that cam with stock push rods in my motor for 10K+ miles.

slowec

iTrader: (9)

I will install 2 of them and compare the valve stem contact . I will put the best ones in. If the stockers almost fit and the .45s are to long, I will order the .25s. I will post my findings, but more opinions are always wanted.

So much for a simple add on

kbracing96

iTrader: (26)

Valve stem contact won't change unless your running adjustable rockers, it the amount of pre-load the lifter will see that will be different.

slowec

iTrader: (9)

Thanks...
So much for a simple add on

Is the extra .025 gonna be to much preload you think. Looking at that amount on a dial caliper its pretty damn small. maybe I should just send em back now? I need a drink

kbracing96

iTrader: (26)

If it was me, I'd run the stock push rods, but that's what I did,

slowec

iTrader: (9)

Look at this picture and see if you stand by your previous statement. I agree to much rod could preload the lifter, but the contact will change with rod length.

Geometry Lesson

All pushrod engines that pivot a rocker arm on a stud determine the location of the rocker-arm tip relative to the valve tip with pushrod length. The small-block Chevy, along with many other production engines, originally came equipped with stamped-steel rocker arms. These rockers used a very wide rocker tip with a very gentle radius that was extremely forgiving when it came to pushrod length. The pushrod length could be short or long and the broad rocker-arm tip would accommodate it.


let me know what you think.

And thanks for reponding. I think all of us are learning.

kbracing96

iTrader: (26)

That is true on the small blocks and with adjustable rocker on these motors, but stock rockers are not adjustable, they tighten down against the saddle and there for the pivot point on the rocker can not change in relationship to the valve, so the contact point will be the same.

See where I'm coming from on this. The rocker will always be in the same location, no mater what push rod you install in the motor, a longer push rod just pushes the lifter piston further into the lifter.