rocker shaft breakage

[wants a tr]

i've done a search on the topic but really didnt find what i was needing.

Here's the problem. Its broke the rocker shaft @ the #1 cylinder TWICE now. The heads were checked b4 the motor was put together. Running CC 981 springs. 212/206 hyd. I know i can just put another shaft on and be done with it, but this has happened twice. there must be something causing it. Does anyone have any ideas? The first time it just broke idlein' at a stop light. 2nd time was about the 1000' foot mark at the track. I let the car shift itself and i dont spin it up hard.

TIA....

 

[Grandnat]

I suspect this happens from overtightening the rocker shafts and causing metal fatigue. But I cannot confirm this

It has happend to me several times, and eveyone I know that is making good power, this happens to as well.

The solution is aftermarket rocker shafts (roller or thicker factory style), or possibly the little caps that RJC sells.

I just bought a set of thicker shafts for this reason.... guess we'll see if that fixes the problem..

if not... I am getting the T&D roller rockers.

 

[V6 Beast]

I was breaking them pretty good too but the ones from Mike Savino at turbo buicks.com haven't broken. I think they are on sale now for $79.95 for shafts and rockers. Torque spec is only 20 ft/lbs on the bolts.


Sully

 

[gnx7]

I've broken one at the #1 myself on my last engine..... get the HD ones like mentioned above.

-GNX7