I had my 383 LE3 H/C put together by a engine builder that does mainly older performance motors - he keeps confusing LT1 with SBC.

I've had problems with the pushrods falling out. I had two fall out of cylinder 1, a friend put them back in after checking that the (hardened) pushrods were not bent. Then we adjusted the valve lash to about 1/4 past 0 (caddy racing lifters) and started the car and another pushrod on the opposite cylinder bank came out. The rebuild was started in 2005 and finished last year, and has had 3 different shops involved.

It has self aligning 1.6 roller rockers and beehive springs. My friend wants to put guideplates on to prevent the rockers from falling out again, suggesting that aggresive ramp on this cam could be a contributing factor - im wondering if that could interfere with the self aligning mechanism of the rocker arms.

My main question is, what would cause the pushrods to keep coming out??

 

How much lift do you have on the cam? SA rockers are not necessarily the best choice for a big cam with a lot of lift.

Did anyone check the pushrod length? Is the wear pattern centered on the tip of the valve?

 

The LT1 is pretty much just a SBC far as a machinist is concerned so I wouldn't necessarily fault the guy there.

Have you checked to make sure the SA part of the rocker is working right? As in not hitting the retainer or anything during travel?

I would tend to agree with your friend in thinking the valvetrain is out of control BUT would strongly disagree with putting guideplates on with SA rockers.

If the build was started that long ago is this a Bauer cam? If so you should be aware some of the cams he was specing were VERY hard to control and the parts he was recommending were NOT capable. I suspect that had a LOT to do with Lloyd no longer using him.

Can you borrow a set of 1.5s and see if slowing the cam down a little that way helps. Either SA without guideplates or non-SA with guideplates. If you do guideplates look at GMPP or Trickflow for cheap and "close enough" or Isky adjustables if you want it to be just right.

 

I use the non-self aligning and have guideplates, I dont see how they would be falling off though with proper lash. You may be setting the lash wrong. There is a serious art to setting the lash. I have done it so many times its not even funny. There for a year every 3rd time I went to the track I was knocking one loose; not enough past 0 lash. Falling completely off though would to me be way too close to 0 lash.

 

Are some of the rockers installed upside down (i.e., the trunion flat spot is facing DOWN on the rocker stud)?

 

You might also look for contact between the valve spring and the rocker. Some of the large diameter springs can hit the rocker body...

 

Silly question but did the builder use a smaller base cam when he built the stroker?

 

The LE3 cam was purchased in 2005.

I will get back to you all with pushrod length and wear pattern on the valve tip. I might invest in NSA rockers if its not something obvious like incorrect pushrod length, upside down rocker, or incorrect valve spring contact, or self aligning mechanism hitting the retainer. The engine builder did assure me that he would put the correct length of pushrod in there while he was building it. My friend did the valve lash while I turned the motor over, he's done it many many times on all sorts of different vehicles.

Sorry I dont know what a small base cam is? The LE3 cam has been used successfully in 383s so i think it should be ok size wise? If we figure this out, and I hope we will I'll be sure to post whatever the solution ends up being!

 

Running beehives with certain lock combos does not allow the use of s/a rockers. If stock locks were used you could use the s/a rocker. The valve tip doesn't stick up enough to contact the roller and rides on the alignment tabs. In such cases a NSA rocker and guideplates are required.

 

I ran into the same problem!!! I have part # in this Post:

https://www.camaroz28.com/forums/sho...d.php?t=817137