1.6 rocker 's on 00' 350 vortec?

[Green meanie]

Will I have to change pushrod length, and has any body else done this to there 350 vortec with good results, and does it mess with programing? any help appreciated.:fsc:

[battyice]

The pushrod length shouldn't change, but it is easy to check; you will need to open up the pushrod slots in the heads for additional clearance. Another concern is the stock valve springs, they can't handle very much lift and 1.6 ratio rockers may cause them to bind.

In my opinion any gains from the 1.6 ratio rockers on a stock engine would be minimal. A set of stock ratio roller rockers would give you the same reduced friction benefits without the clearance issues.

[Boosted-Z71]

Hate to disagree but anytime you change any valve train components other than stock (I still check the stock stuff for peace of mind) you need to check the entire VT geometry. 1.6 RR are not a slap on item, you will need to adjust the pushrod length to obtain the correct rocker tip to valve tip contact area. There are many posts on this. If you dont do this you can wear out valve guides, damage the tips of the valves, ruin your nicce new rockers & worst of all the motor could loose cam lift from the rocker arm being mis-aligned & not going straight up & down on the valve & sliding across the tip surface. There are alot of good articles on the net that do a much better job of explaining this. The previous post is correct that you may need to open up the pushrod hole, I have seen Vortec heads that had plenty of room & others that needed more.

Boosted

[S/C Z71]

Not worth it.

[SuperChevy17]

I've got 1.6s on my new engine build, but I swapped cams too. You'll see a little gain, but don't expect anything more without additional upgrades. I don't know how the stock computer will handle the additional valve lift. It may compensate, it may not. Vortecs use self-aligning rockers, so you don't really have to worry about alignment issues. Just cut the pushrod holes to 1/2" for clearance.

[Boosted-Z71]

The alignment your refering to is left & right on the stem, The Vortec are self-centering as they have a washer on either side of the pin that keeps them on the stem. You need to check your valve train geometry if you change parts other than stock. I have seen cam lift decrease from adding rockers & they are now not centered in the valve front to back, so rather than a 90 degree pressure angle on the tip you get a different angle that with the roller, now has a tendency to slide across, Its a function of Geometry & friction.

More than likely the reason you did not see much increase with cam change is you probably went backwards on your actual valve lift (not cam card lift). There are reasons that they make degree wheels & indicators to check such things.


Boosted

[SuperChevy17]

I didn't say that I saw little increase. I stated that he would see very little increase by using 1.6 rockers and no other mods.